JP2019129292A - Thermal treatment apparatus and thermal treatment method - Google Patents

Abstract

To provide a thermal treatment apparatus and a thermal treatment method, capable of accurately measuring a reflectance of a substrate by suppressing pattern dependency.SOLUTION: Light for reflectance measurement emitted from a light projection part 300 is reflected by a half mirror 236 and irradiated to a surface of a semiconductor wafer W supported by a rotation support part 237. Reflection light obtained by reflecting the light irradiated from one light projection part 300 by three different places of the surface of the semiconductor wafer W is received by three light-receiving parts 235a, 235b, and 235c. A reflectance calculation part 31 calculates a reflectance in each of three reflection positions from intensity of the light irradiated by the light projection part 300 and the intensity of the reflection light received by each of three light-receiving parts 235a, 235b, and 235c and further, calculates an average value of the reflectances. Reflectances of a plurality of places are measured so that the pattern dependency is suppressed to accurately measure the reflectance of the semiconductor wafer W.SELECTED DRAWING: Figure 12

Description

  The present invention relates to a heat treatment apparatus and a heat treatment method for heating a thin plate-shaped precision electronic substrate (hereinafter, simply referred to as a “substrate”) such as a semiconductor wafer by heating the substrate.

  In the manufacturing process of a semiconductor device, flash lamp annealing (FLA) that heats a semiconductor wafer in a very short time has attracted attention. Flash lamp annealing is to expose the surface of a semiconductor wafer to a flash light by using a xenon flash lamp (hereinafter simply referred to as a "flash lamp" to mean a xenon flash lamp), thereby exposing only the surface of the semiconductor wafer. It is a heat treatment technology that raises the temperature in a short time (several milliseconds or less).

  The radiation spectral distribution of a xenon flash lamp ranges from the ultraviolet region to the near infrared region, has a shorter wavelength than the conventional halogen lamp, and almost coincides with the fundamental absorption band of a silicon semiconductor wafer. Therefore, when the semiconductor wafer is irradiated with flash light from the xenon flash lamp, it is possible to rapidly increase the temperature of the semiconductor wafer because the amount of transmitted light is small. It has also been found that only the vicinity of the surface of the semiconductor wafer can be selectively heated if the flash light irradiation is performed for an extremely short time of several milliseconds or less.

  Such flash lamp annealing is used for processes that require heating for a very short time, for example, activation of impurities typically implanted in a semiconductor wafer. The surface of the semiconductor wafer can be heated to the activation temperature for a very short time by irradiating a flash light from the flash lamp to the surface of the semiconductor wafer in which the impurity is implanted by the ion implantation method, and the impurity is diffused deeply. Only the impurity activation can be performed without causing the

  In flash lamp annealing, flash light irradiation with an extremely short irradiation time is performed to instantaneously raise the temperature of the semiconductor wafer. Therefore, it is not possible to feedback control the emission intensity of the flash lamp in real time while measuring the wafer temperature. For this reason, it is necessary to calculate the ultimate temperature of the surface of the semiconductor wafer at the time of flash light irradiation beforehand, and adjust the light emission intensity of the flash lamp so that the surface rises to a predetermined target temperature. Patent Document 1 discloses a technique of measuring the reflectance of a semiconductor wafer to be treated and calculating the temperature reached by the surface of the semiconductor wafer at the time of flash light irradiation based on the reflectance. In the technique disclosed in Patent Document 1, the surface of a semiconductor wafer is irradiated with halogen light from a halogen lamp, and the reflectance of the semiconductor wafer is calculated from the intensity of the reflected light.

JP 2014-45067 A

  However, various patterns for device formation are often formed on the surface of a semiconductor wafer to be processed. If a plurality of different patterns are formed on the surface of the semiconductor wafer and there are patterns, the measurement results will differ depending on the portion irradiated with the halogen light for reflectance measurement, causing a problem that accurate reflectance can not be measured .

  Further, for example, in FinFET or the like, a three-dimensional pattern is formed on the surface of a semiconductor wafer, and the reflectance may vary depending on the direction even at the same location. That is, in the method of irradiating light to the surface of a semiconductor wafer and measuring the reflectance from the intensity of the reflected light, there is a strong dependence on the pattern and there is a problem that accurate measurement of the reflectance is difficult.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a heat treatment apparatus and a heat treatment method capable of accurately measuring the reflectance of a substrate while suppressing pattern dependency.

  In order to solve the above problems, the invention of claim 1 is a heat treatment apparatus for heating a substrate by irradiating the substrate with light, the lamp for heating the substrate by irradiating the substrate with light, and A rotating support unit for supporting and rotating the substrate, a light projecting unit for emitting light for measuring reflectance to a portion other than the rotation center of the substrate rotated by the rotation supporting unit; The reflectance of the substrate is calculated from the light receiving unit that receives the reflected light reflected by the substrate, the intensity of the light irradiated by the light projecting unit, and the intensity of the reflected light received by the light receiving unit. A reflectance calculation unit.

  The invention according to claim 2 is the heat treatment apparatus according to claim 1, further comprising a plurality of light projecting sections that irradiate a plurality of portions having different distances from the rotation center of the substrate with light for reflectance measurement. It is characterized by.

  The invention of claim 3 is a heat treatment apparatus for heating a substrate by irradiating the substrate with light, a heating lamp for irradiating the substrate with light to heat the substrate, and a reflectance measurement for the substrate. A light projecting unit that irradiates light for use, a plurality of light receiving units that receive reflected light reflected from a plurality of locations on the substrate, and a light emitted by the light projecting unit And a reflectance calculating section that calculates the reflectance of the plurality of locations on the substrate from the intensity of the light and the intensity of the reflected light received by the plurality of light receiving sections.

  According to a fourth aspect of the invention, in the heat treatment apparatus according to the third aspect of the invention, the reflectance calculation unit calculates an average reflectance that is an average value of the reflectances at the plurality of locations.

  Further, in the heat treatment apparatus according to claim 3, the invention of claim 5 irradiates the plurality of locations from the heating lamp based on the reflectance of the plurality of locations calculated by the reflectance calculation unit. The light intensity is adjusted.

  In the heat treatment apparatus for heating the substrate by irradiating the substrate with light, the heating lamp for heating the substrate by irradiating the substrate with light, and the measurement of the reflectance of the substrate For emitting light, a plurality of light receiving units for receiving light reflected from the light emitting unit reflected at a specific portion of the substrate, and light emitted from the light emitting unit And a reflectance calculating unit that calculates the reflectance of the specific portion of the substrate from the intensity of the reflected light and the intensity of the reflected light received by the plurality of light receiving units.

  The invention according to claim 7 is the heat treatment method of heating the substrate by irradiating the substrate with light, wherein a heating step of irradiating the substrate with light from the lamp for heating and heating the substrate is rotated. An irradiation step of irradiating a portion other than the center of rotation of the substrate with light for reflectance measurement, a light receiving step of receiving the reflected light reflected by the substrate and the light irradiated in the irradiation step, and the irradiation A reflectance calculating step of calculating the reflectance of the substrate from the intensity of the light irradiated in the step and the intensity of the reflected light received in the light receiving step.

  In the heat treatment method according to the invention of claim 7, in the irradiation step, a plurality of portions having different distances from the center of rotation of the substrate are irradiated with light for measuring reflectance. It is characterized by.

  The invention according to claim 9 is a heat treatment method of heating the substrate by irradiating the substrate with light, the heating step of irradiating the substrate with light from the lamp for heating and heating the substrate, and An irradiation step of irradiating light for reflectance measurement, a light receiving step of receiving reflected light reflected at a plurality of locations of the substrate by a plurality of light receiving units, and the irradiation step. Providing a reflectance calculating step of calculating the reflectance of the plurality of portions of the substrate from the intensity of the light irradiated in step b and the intensity of the reflected light received by the plurality of light receiving portions in the light receiving step. Features.

  According to a tenth aspect of the present invention, in the heat treatment method according to the ninth aspect of the invention, in the reflectance calculation step, an average reflectance that is an average value of the reflectances at the plurality of locations is calculated.

  In the heat treatment method according to the invention of claim 9, according to the invention of claim 11, the heating lamp is used in the heating process based on the reflectances of the plurality of places calculated in the reflectance calculation process. The intensity of light applied to the plurality of locations before is adjusted.

  The invention according to claim 12 is a heat treatment method of heating the substrate by irradiating the substrate with light, wherein a heating step of irradiating the substrate with light from the lamp for heating to heat the substrate; An irradiation step of irradiating light for reflectance measurement, a light receiving step of receiving reflected light reflected by a specific portion of the substrate by a plurality of light receiving units, and the irradiation step. Providing a reflectance calculating step of calculating the reflectance of the specific portion of the substrate from the intensity of the light irradiated in step b and the intensity of the reflected light received by the plurality of light receiving portions in the light receiving step. Features.

  According to the first and second aspects of the present invention, since light for reflectance measurement is irradiated to a portion other than the rotation center of the substrate to be rotated, the reflectance at a plurality of locations on the substrate is measured. The reflectance of the substrate can be accurately measured by suppressing the pattern dependency.

  According to the third to fifth aspects of the present invention, the reflectance of the plurality of locations of the substrate is calculated from the intensity of the reflected light reflected at the plurality of locations of the substrate. The reflectance can be accurately measured.

  In particular, according to the invention of claim 5, the in-plane temperature distribution of the substrate is made uniform in order to adjust the intensity of the light irradiated to the plurality of locations from the heating lamp based on the calculated reflectances of the plurality of locations. be able to.

  According to the invention of claim 6, since the reflectance of the specific part of the substrate is calculated from the intensities of the plurality of reflected lights reflected at the specific part of the substrate, the scattering component of the specific part is also measured. It is possible to accurately measure the reflectance of the substrate while suppressing the pattern dependency.

  According to the seventh and eighth aspects of the invention, since the portion other than the center of rotation of the substrate to be rotated is irradiated with the light for reflectance measurement, the reflectance at a plurality of locations on the substrate is measured. The reflectance of the substrate can be accurately measured while suppressing the pattern dependency.

  According to the ninth to eleventh aspects of the present invention, since the reflectance at a plurality of locations on the substrate is calculated from the intensity of the reflected light reflected at the plurality of locations on the substrate, pattern dependency is suppressed and The reflectance can be accurately measured.

  In particular, according to the invention of claim 11, the in-plane temperature distribution of the substrate is made uniform in order to adjust the intensity of the light irradiated to the plurality of locations from the heating lamp based on the calculated reflectances of the plurality of locations. be able to.

  According to the twelfth aspect of the present invention, since the reflectance of the specific portion of the substrate is calculated from the intensity of the plurality of reflected lights reflected at the specific portion of the substrate, the scattering component of the specific portion is also measured. It is possible to accurately measure the reflectance of the substrate while suppressing the pattern dependency.

It is a top view showing a heat treatment apparatus concerning the present invention. It is a front view of the heat processing apparatus of FIG. It is a longitudinal cross-sectional view which shows the structure of a heat processing part. It is a perspective view which shows the whole external appearance of a holding | maintenance part. It is a top view of a susceptor. It is a sectional view of a susceptor. It is a top view of a transfer mechanism. It is a side view of a transfer mechanism. It is a top view showing arrangement of a plurality of halogen lamps. It is a figure which shows the structure of a reflectance measurement part. It is a figure which shows typically the reflectance measurement area | region of 1st Embodiment. It is a figure which shows the structure of the reflectance measurement part of 2nd Embodiment. It is a figure which shows the structure of the reflectance measurement part of 3rd Embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

First Embodiment
First, the overall schematic configuration of the heat treatment apparatus 100 according to the present invention will be described. FIG. 1 is a plan view showing a heat treatment apparatus 100 according to the present invention, and FIG. 2 is a front view thereof. The heat treatment apparatus 100 is a flash lamp annealing apparatus which irradiates flash light to a disk-shaped semiconductor wafer W as a substrate to heat the semiconductor wafer W. The size of the semiconductor wafer W to be processed is not particularly limited, and is, for example, φ300 mm or φ450 mm. Impurities are implanted into the semiconductor wafer W before being carried into the heat treatment apparatus 100, and activation processing of the impurities implanted by the heat treatment by the heat treatment apparatus 100 is performed. In FIG. 1 and the subsequent drawings, the dimensions and the numbers of the respective parts are exaggerated or simplified as necessary for easy understanding. Further, in each of FIGS. 1 to 3, in order to clarify the directional relationship thereof, an XYZ orthogonal coordinate system in which the Z axis direction is a vertical direction and the XY plane is a horizontal surface is attached.

  As shown in FIGS. 1 and 2, the heat treatment apparatus 100 carries an unprocessed semiconductor wafer W from the outside into the apparatus and carries out the processed semiconductor wafer W out of the apparatus. Alignment unit 230 for positioning the semiconductor wafer W, two cooling units 130 and 140 for cooling the semiconductor wafer W after the heat treatment, a heat treatment unit 160 for performing flash heating treatment on the semiconductor wafer W, and cooling units 130 and 140 and A transfer robot 150 for transferring the semiconductor wafer W to the thermal processing unit 160 is provided. The heat treatment apparatus 100 further includes a control unit 3 that controls the operation mechanism provided in each processing unit described above and the transfer robot 150 to advance the flash heating process of the semiconductor wafer W.

  The indexer section 101 takes out the unprocessed semiconductor wafer W from each carrier C and load port 110 on which a plurality of carriers C (two in the present embodiment) are placed side by side, and the semiconductor wafer processed to each carrier C. And a delivery robot 120 for storing W. Carrier C containing an untreated semiconductor wafer W is transported by an automated guided vehicle (AGV, OHT) or the like and placed on load port 110, and carrier C containing a processed semiconductor wafer W is an unattended carrier Is taken away from the load port 110.

  Further, in the load port 110, the carrier C is configured to be movable up and down as shown by an arrow CU in FIG. 2 so that the delivery robot 120 can carry out the loading and unloading of any semiconductor wafer W with respect to the carrier C. ing. As the form of the carrier C, in addition to FOUP (front opening unified pod) for storing the semiconductor wafer W in an enclosed space, OC (open for open air) exposes the SMIF (Standard Mechanical Inter Face) pod and the stored semiconductor wafer W cassette).

  In addition, the delivery robot 120 is capable of sliding movement as shown by an arrow 120S in FIG. 1, turning operation and raising / lowering operation as shown by an arrow 120R. Thereby, the delivery robot 120 takes in and out the semiconductor wafer W with respect to the two carriers C, and delivers the semiconductor wafer W with respect to the alignment unit 230 and the two cooling units 130 and 140. Loading and unloading of the semiconductor wafer W with respect to the carrier C by the delivery robot 120 is performed by sliding movement of the hand 121 and lifting and lowering movement of the carrier C. The semiconductor wafer W is transferred between the delivery robot 120 and the alignment unit 230 or the cooling units 130 and 140 by the slide movement of the hand 121 and the lifting operation of the delivery robot 120.

  The alignment unit 230 is provided connected to the side of the indexer unit 101 along the Y-axis direction. The alignment unit 230 is a processing unit that rotates the semiconductor wafer W in the horizontal plane to direct it to the flash heating. The alignment unit 230 is a mechanism (a rotation support unit 237 and a rotation motor 238 in FIG. 10) for supporting and rotating the semiconductor wafer W horizontally in an alignment chamber 231 which is a housing made of aluminum alloy, and a semiconductor A mechanism or the like for optically detecting a notch, an orientation flat, or the like formed in the peripheral portion of the wafer W is provided. Further, the alignment chamber 231 is provided with a reflectance measurement unit 232 that measures the reflectance of the surface of the semiconductor wafer W supported therein. The reflectance measurement unit 232 irradiates the surface of the semiconductor wafer W with light, receives the reflected light reflected by the surface, and measures the reflectance of the surface of the semiconductor wafer W from the intensity of the reflected light. The configuration of the reflectance measurement unit 232 will be further described later.

  Delivery of the semiconductor wafer W to the alignment unit 230 is performed by the delivery robot 120. The semiconductor wafer W is delivered from the delivery robot 120 to the alignment chamber 231 so that the wafer center is positioned at a predetermined position. The alignment unit 230 rotates the semiconductor wafer W about the vertical axis about the central portion of the semiconductor wafer W received from the indexer unit 101 as a rotation center and optically detects a notch or the like to adjust the direction of the semiconductor wafer W Do. Further, the reflectance measurement unit 232 measures the reflectance of the surface of the semiconductor wafer W. The semiconductor wafer W whose orientation has been adjusted is taken out of the alignment chamber 231 by the delivery robot 120.

  A transfer chamber 170 that houses the transfer robot 150 is provided as a transfer space for the semiconductor wafer W by the transfer robot 150. The processing chamber 6 of the thermal processing unit 160, the first cool chamber 131 of the cooling unit 130, and the second cool chamber 141 of the cooling unit 140 are connected in communication to three sides of the transfer chamber 170.

  The heat treatment unit 160, which is a main part of the heat treatment apparatus 100, is a substrate processing unit that performs flash heat treatment by irradiating flash light (flash light) from a xenon flash lamp FL onto the pre-heated semiconductor wafer W.

  The two cooling units 130 and 140 have substantially the same configuration. The cooling units 130 and 140 respectively include a metal cooling plate and a quartz plate placed on the upper surface thereof in the first cool chamber 131 and the second cool chamber 141 which are aluminum alloy casings ( Both are not shown). The said cooling plate is temperature-controlled to normal temperature (about 23 degreeC) by Peltier device or thermostatic water circulation. The semiconductor wafer W subjected to the flash heating process in the thermal processing unit 160 is carried into the first cool chamber 131 or the second cool chamber 141, placed on the quartz plate, and cooled.

  Both the first cool chamber 131 and the second cool chamber 141 are connected between the indexer unit 101 and the transfer chamber 170. In the first cool chamber 131 and the second cool chamber 141, two openings for carrying the semiconductor wafer W in and out are formed. Of the two openings of the first cool chamber 131, the opening connected to the indexer portion 101 can be opened and closed by the gate valve 181. On the other hand, the opening connected to the transfer chamber 170 of the first cool chamber 131 can be opened and closed by the gate valve 183. That is, the first cool chamber 131 and the indexer unit 101 are connected via the gate valve 181, and the first cool chamber 131 and the transfer chamber 170 are connected via the gate valve 183.

  When the semiconductor wafer W is transferred between the indexer unit 101 and the first cool chamber 131, the gate valve 181 is opened. When the semiconductor wafer W is transferred between the first cool chamber 131 and the transfer chamber 170, the gate valve 183 is opened. When the gate valve 181 and the gate valve 183 are closed, the inside of the first cool chamber 131 is a sealed space.

  Of the two openings of the second cool chamber 141, the opening connected to the indexer unit 101 can be opened and closed by a gate valve 182. On the other hand, the opening connected to the transfer chamber 170 of the second cool chamber 141 can be opened and closed by the gate valve 184. That is, the second cool chamber 141 and the indexer unit 101 are connected via the gate valve 182, and the second cool chamber 141 and the transfer chamber 170 are connected via the gate valve 184.

  When the semiconductor wafer W is transferred between the indexer unit 101 and the second cool chamber 141, the gate valve 182 is opened. When the semiconductor wafer W is transferred between the second cool chamber 141 and the transfer chamber 170, the gate valve 184 is opened. When the gate valve 182 and the gate valve 184 are closed, the inside of the second cool chamber 141 is a sealed space.

  Furthermore, each of the cooling units 130 and 140 includes a gas supply mechanism that supplies clean nitrogen gas to the first cool chamber 131 and the second cool chamber 141 and an exhaust mechanism that exhausts the atmosphere in the chamber. The gas supply mechanism and the exhaust mechanism may be capable of switching the flow rate in two stages.

  The transfer robot 150 provided in the transfer chamber 170 can be turned around an axis along the vertical direction as indicated by an arrow 150R. The transfer robot 150 has two link mechanisms consisting of a plurality of arm segments, and transfer hands 151a and 151b for holding the semiconductor wafer W are provided at the tips of the two link mechanisms. These transport hands 151a and 151b are vertically spaced apart from each other by a predetermined pitch, and can be slid linearly in the same horizontal direction independently by a link mechanism. Further, the transfer robot 150 moves up and down the two transfer hands 151a and 151b in a state of being separated by a predetermined pitch by moving up and down the base on which the two link mechanisms are provided.

  When the transfer robot 150 transfers the semiconductor wafer W as a transfer partner of the first cool chamber 131, the second cool chamber 141, or the heat treatment unit 160, first, the transfer hands 151a and 151b are moved to each other. Then, it turns so as to face the delivery partner, and then moves up and down (or while it is turning) to position any one of the transfer hands at the height at which the semiconductor wafer W is delivered to the delivery partner. Then, the transfer hand 151 a (151 b) is linearly moved in the horizontal direction to transfer the semiconductor wafer W to the other party.

  The transfer of the semiconductor wafer W between the transfer robot 150 and the transfer robot 120 can be performed via the cooling units 130 and 140. That is, the first cool chamber 131 of the cooling unit 130 and the second cool chamber 141 of the cooling unit 140 also function as a pass for delivering the semiconductor wafer W between the transfer robot 150 and the delivery robot 120. . Specifically, the semiconductor wafer W is transferred when the other receives the semiconductor wafer W transferred by the one of the transfer robot 150 or the delivery robot 120 to the first cool chamber 131 or the second cool chamber 141.

  As described above, the gate valves 181 and 182 are provided between the first cool chamber 131 and the second cool chamber 141 and the indexer unit 101, respectively. Further, gate valves 183 and 184 are provided between the transfer chamber 170 and the first cool chamber 131 and the second cool chamber 141, respectively. Furthermore, a gate valve 185 is provided between the transfer chamber 170 and the processing chamber 6 of the thermal processing unit 160. When the semiconductor wafer W is transported in the heat treatment apparatus 100, these gate valves are appropriately opened and closed.

  In addition, an oximeter 155 is provided inside the transfer chamber 170 (FIG. 2). The oximeter 155 measures the oxygen concentration in the transfer chamber 170. Further, nitrogen gas is also supplied to the transfer chamber 170 and the alignment chamber 231 from the gas supply unit, and the atmosphere inside them is exhausted by the exhaust unit (all not shown).

  Next, the configuration of the heat treatment unit 160 will be described. FIG. 3 is a longitudinal sectional view showing the configuration of the heat treatment section 160. As shown in FIG. The thermal processing unit 160 includes a processing chamber 6 for housing and heating the semiconductor wafer W, a flash lamp house 5 containing a plurality of flash lamps FL, and a halogen lamp house 4 containing a plurality of halogen lamps HL. Prepare. A flash lamp house 5 is provided above the processing chamber 6, and a halogen lamp house 4 is provided below the processing chamber 6. Further, the thermal processing unit 160 holds the semiconductor wafer W in the horizontal posture inside the processing chamber 6, and the transfer mechanism 10 for delivering the semiconductor wafer W between the holding unit 7 and the transfer robot 150. And.

  The processing chamber 6 is configured by mounting quartz chamber windows above and below a cylindrical chamber side portion 61. The chamber side 61 has a generally cylindrical shape with an open top and bottom, the upper opening is fitted with the upper chamber window 63 and closed, and the lower opening is fitted with the lower chamber window 64 and closed ing. The upper chamber window 63 constituting the ceiling portion of the processing chamber 6 is a disk-shaped member formed of quartz, and functions as a quartz window that transmits flash light emitted from the flash lamp FL into the processing chamber 6. The lower chamber window 64 constituting the floor of the processing chamber 6 is also a disk-shaped member made of quartz, and functions as a quartz window that transmits light from the halogen lamp HL into the processing chamber 6.

  A reflection ring 68 is attached to the upper part of the inner wall surface of the chamber side part 61, and a reflection ring 69 is attached to the lower part. The reflection rings 68 and 69 are both formed in an annular shape. The upper reflective ring 68 is mounted by fitting from the upper side of the chamber side 61. On the other hand, the lower reflection ring 69 is mounted by being fitted from the lower side of the chamber side 61 and fixed with a screw (not shown). That is, the reflection rings 68 and 69 are both detachably mounted on the chamber side 61. An inner space of the processing chamber 6, that is, a space surrounded by the upper chamber window 63, the lower chamber window 64, the chamber side 61 and the reflection rings 68 and 69 is defined as a heat treatment space 65.

  By attaching the reflection rings 68 and 69 to the chamber side portion 61, a recess 62 is formed on the inner wall surface of the processing chamber 6. That is, a recess 62 surrounded by a central portion of the inner wall surface of the chamber side 61 to which the reflective rings 68 and 69 are not attached, the lower end surface of the reflective ring 68 and the upper end surface of the reflective ring 69 is formed. . The recess 62 is formed in an annular shape along the horizontal direction on the inner wall surface of the processing chamber 6 and surrounds the holding unit 7 that holds the semiconductor wafer W. The chamber side 61 and the reflection rings 68 and 69 are formed of a metal material (for example, stainless steel) which is excellent in strength and heat resistance.

  The chamber side 61 is formed with a transfer opening (furnace port) 66 for carrying the semiconductor wafer W into and out of the processing chamber 6. The transfer opening 66 can be opened and closed by a gate valve 185. The transfer opening 66 is connected in communication with the outer peripheral surface of the recess 62. Therefore, when the gate valve 185 opens the transfer opening 66, the semiconductor wafer W is carried into the heat treatment space 65 from the transfer opening 66 through the recess 62 and the semiconductor wafer W is unloaded from the heat treatment space 65. It can be performed. Further, when the gate valve 185 closes the transfer opening 66, the heat treatment space 65 in the processing chamber 6 is made a sealed space.

Further, a gas supply hole 81 for supplying a processing gas to the heat treatment space 65 is formed on the upper inner wall of the processing chamber 6. The gas supply hole 81 is formed at a position above the recess 62 and may be provided in the reflection ring 68. The gas supply hole 81 is communicably connected to the gas supply pipe 83 via a buffer space 82 formed in an annular shape inside the side wall of the processing chamber 6. The gas supply pipe 83 is connected to the processing gas supply source 85. Further, a valve 84 is interposed in the middle of the path of the gas supply pipe 83. When the valve 84 is opened, the processing gas is supplied from the processing gas supply source 85 to the buffer space 82. The process gas flowing into the buffer space 82 flows so as to expand in the buffer space 82 having a smaller fluid resistance than the gas supply holes 81, and is supplied from the gas supply holes 81 into the heat treatment space 65. As the processing gas, an inert gas such as nitrogen (N ₂ ) or a reactive gas such as hydrogen (H ₂ ) or ammonia (NH ₃ ) can be used (in this embodiment, nitrogen).

  On the other hand, a gas exhaust hole 86 for exhausting the gas in the heat treatment space 65 is formed in the lower portion of the inner wall of the processing chamber 6. The gas exhaust hole 86 is formed at a lower position than the recess 62, and may be provided in the reflection ring 69. The gas exhaust hole 86 is communicatively connected to the gas exhaust pipe 88 via a buffer space 87 formed annularly inside the side wall of the processing chamber 6. The gas exhaust pipe 88 is connected to the exhaust mechanism 190. Further, a valve 89 is interposed in the middle of the path of the gas exhaust pipe 88. When the valve 89 is opened, the gas in the heat treatment space 65 is exhausted from the gas exhaust hole 86 through the buffer space 87 to the gas exhaust pipe 88. A plurality of gas supply holes 81 and gas exhaust holes 86 may be provided along the circumferential direction of the processing chamber 6, or may be slit-shaped. The processing gas supply source 85 and the exhaust mechanism 190 may be a mechanism provided in the heat treatment apparatus 100 or may be a utility of a factory where the heat treatment apparatus 100 is installed.

  In addition, a gas exhaust pipe 191 for exhausting the gas in the heat treatment space 65 is also connected to the tip of the transfer opening 66. The gas exhaust pipe 191 is connected to an exhaust mechanism 190 via a valve 192. By opening the valve 192, the gas in the processing chamber 6 is exhausted through the transfer opening 66.

  FIG. 4 is a perspective view showing the overall appearance of the holding unit 7. The holding unit 7 is configured to include a base ring 71, a connecting unit 72, and a susceptor 74. The base ring 71, the connecting portion 72 and the susceptor 74 are all formed of quartz. That is, the whole of the holding portion 7 is formed of quartz.

  The base ring 71 is an arc-shaped quartz member which is partially missing from the annular shape. This missing portion is provided to prevent interference between the transfer arm 11 of the transfer mechanism 10 described later and the base ring 71. The base ring 71 is supported on the wall surface of the processing chamber 6 by being placed on the bottom surface of the recess 62 (see FIG. 3). On the top surface of the base ring 71, a plurality of connecting portions 72 (four in the present embodiment) are provided upright along the circumferential direction of the annular shape. The connecting portion 72 is also a quartz member and is fixed to the base ring 71 by welding.

  The susceptor 74 is supported by four connecting portions 72 provided on the base ring 71. FIG. 5 is a plan view of the susceptor 74. As shown in FIG. 6 is a cross-sectional view of the susceptor 74. As shown in FIG. The susceptor 74 includes a holding plate 75, a guide ring 76 and a plurality of substrate support pins 77. The holding plate 75 is a substantially circular flat member made of quartz. The diameter of the holding plate 75 is larger than the diameter of the semiconductor wafer W. That is, the holding plate 75 has a larger planar size than the semiconductor wafer W.

  A guide ring 76 is installed on the peripheral edge of the upper surface of the holding plate 75. The guide ring 76 is an annular member having an inner diameter larger than the diameter of the semiconductor wafer W. For example, when the diameter of the semiconductor wafer W is φ300 mm, the inner diameter of the guide ring 76 is φ320 mm. The inner periphery of the guide ring 76 is tapered so as to widen upward from the holding plate 75. The guide ring 76 is formed of quartz similar to the holding plate 75. The guide ring 76 may be welded to the upper surface of the holding plate 75 or may be fixed to the holding plate 75 by a separately processed pin or the like. Alternatively, the holding plate 75 and the guide ring 76 may be processed as an integral member.

  A region inside the guide ring 76 on the upper surface of the holding plate 75 is a flat holding surface 75 a that holds the semiconductor wafer W. A plurality of substrate support pins 77 are provided upright on the holding surface 75 a of the holding plate 75. In the present embodiment, a total of 12 substrate support pins 77 are erected every 30 ° along the circumference of a concentric circle with the outer circumference circle of the holding surface 75a (the inner circumference circle of the guide ring 76). The diameter of the circle where the 12 substrate support pins 77 are arranged (the distance between the opposing substrate support pins 77) is smaller than the diameter of the semiconductor wafer W, and if the diameter of the semiconductor wafer W is φ300 mm, φ270 mm to φ280 mm (this embodiment) In the form, φ270 mm). Each substrate support pin 77 is formed of quartz. The plurality of substrate support pins 77 may be provided on the upper surface of the holding plate 75 by welding, or may be processed integrally with the holding plate 75.

  Returning to FIG. 4, the four connecting portions 72 erected on the base ring 71 and the peripheral portion of the holding plate 75 of the susceptor 74 are fixed by welding. That is, the susceptor 74 and the base ring 71 are fixedly connected by the connecting portion 72. By supporting the base ring 71 of the holder 7 on the wall surface of the processing chamber 6, the holder 7 is attached to the processing chamber 6. In a state where the holding unit 7 is mounted in the processing chamber 6, the holding plate 75 of the susceptor 74 is in a horizontal posture (a posture in which the normal line coincides with the vertical direction). That is, the holding surface 75a of the holding plate 75 is a horizontal surface.

  The semiconductor wafer W carried into the processing chamber 6 is placed and held in a horizontal posture on the susceptor 74 of the holding unit 7 attached to the processing chamber 6. At this time, the semiconductor wafer W is supported by the twelve substrate support pins 77 erected on the holding plate 75 and held by the susceptor 74. More strictly, the upper end portions of the twelve substrate support pins 77 contact the lower surface of the semiconductor wafer W to support the semiconductor wafer W. Since the heights of the twelve substrate support pins 77 (the distance from the upper end of the substrate support pins 77 to the holding surface 75 a of the holding plate 75) are uniform, the semiconductor wafer W is horizontally oriented by the twelve substrate support pins 77. It can be supported.

  Further, the semiconductor wafer W is supported by a plurality of substrate support pins 77 at a predetermined interval from the holding surface 75 a of the holding plate 75. The thickness of the guide ring 76 is larger than the height of the substrate support pin 77. Therefore, the horizontal displacement of the semiconductor wafer W supported by the plurality of substrate support pins 77 is prevented by the guide ring 76.

  As shown in FIGS. 4 and 5, the holding plate 75 of the susceptor 74 has an opening 78 penetrating vertically. The opening 78 is provided to receive radiation (infrared light) emitted from the lower surface of the semiconductor wafer W held by the susceptor 74, with the radiation thermometer 20 (see FIG. 3). That is, the radiation thermometer 20 receives light emitted from the lower surface of the semiconductor wafer W held by the susceptor 74 through the opening 78, and the temperature of the semiconductor wafer W is measured by a separate detector. Furthermore, four through holes 79 are formed in the holding plate 75 of the susceptor 74 so that lift pins 12 of the transfer mechanism 10 described later pass therethrough for delivery of the semiconductor wafer W.

  FIG. 7 is a plan view of the transfer mechanism 10. FIG. 8 is a side view of the transfer mechanism 10. The transfer mechanism 10 includes two transfer arms 11. The transfer arm 11 has an arc shape along the generally annular recess 62. Two lift pins 12 are erected on each transfer arm 11. Each transfer arm 11 is rotatable by a horizontal movement mechanism 13. The horizontal movement mechanism 13 transfers the pair of transfer arms 11 to the holding unit 7 at the transfer operation position (solid line position in FIG. 7) for transferring the semiconductor wafer W and the semiconductor wafer W held by the holding unit 7. Horizontal movement is performed between a retracted position (two-dot chain line position in FIG. 7) which does not overlap in plan view. As the horizontal movement mechanism 13, each transfer arm 11 may be rotated by an individual motor, or a pair of transfer arms 11 may be interlocked by one motor using a link mechanism. It may be moved.

  Further, the pair of transfer arms 11 are moved up and down together with the horizontal movement mechanism 13 by the elevation mechanism 14. When the lifting mechanism 14 lifts the pair of transfer arms 11 at the transfer operation position, a total of four lift pins 12 pass through the through holes 79 (see FIGS. 4 and 5) formed in the susceptor 74 and lift pins The upper end of 12 protrudes from the upper surface of the susceptor 74. On the other hand, when the lifting mechanism 14 lowers the pair of transfer arms 11 at the transfer operation position to extract the lift pins 12 from the through holes 79 and the horizontal movement mechanism 13 moves the pair of transfer arms 11 to open. The transfer arm 11 moves to the retracted position. The retracted position of the pair of transfer arms 11 is immediately above the base ring 71 of the holder 7. Since the base ring 71 is mounted on the bottom surface of the recess 62, the retracted position of the transfer arm 11 is inside the recess 62. An exhaust mechanism (not shown) is provided in the vicinity of the portion where the drive unit (horizontal movement mechanism 13 and lifting mechanism 14) of transfer mechanism 10 is provided, and the atmosphere around the drive unit of transfer mechanism 10 is provided. Are discharged to the outside of the processing chamber 6.

  Returning to FIG. 3, the flash lamp house 5 provided above the processing chamber 6 includes a light source including a plurality of (30 in the present embodiment) xenon flash lamps FL inside the housing 51, and the light source of the light source. And a reflector 52 provided to cover the top. In addition, a lamp light emission window 53 is attached to the bottom of the housing 51 of the flash lamp house 5. The lamp light emission window 53 constituting the floor of the flash lamp house 5 is a plate-like quartz window formed of quartz. By installing the flash lamp house 5 above the processing chamber 6, the lamp light emission window 53 faces the upper chamber window 63. The flash lamp FL irradiates the heat treatment space 65 with flash light from above the processing chamber 6 through the lamp light emission window 53 and the upper chamber window 63.

  The plurality of flash lamps FL are rod-shaped lamps each having a long cylindrical shape, and the longitudinal direction of each is along the main surface of the semiconductor wafer W held by the holder 7 (that is, along the horizontal direction) They are arranged in a plane so as to be parallel to each other. Therefore, the plane formed by the arrangement of the flash lamps FL is also a horizontal plane.

  The xenon flash lamp FL has a rod-like glass tube (discharge tube) in which xenon gas is enclosed and an anode and a cathode connected to a capacitor are disposed at both ends, and attached on the outer peripheral surface of the glass tube And a triggered electrode. Since xenon gas is an insulator electrically, no electricity flows in the glass tube under normal conditions even if charge is stored in the capacitor. However, when a high voltage is applied to the trigger electrode to break the insulation, the electricity stored in the capacitor instantaneously flows in the glass tube, and light is emitted by excitation of atoms or molecules of xenon at that time. In such a xenon flash lamp FL, the electrostatic energy stored in advance in the capacitor is converted into an extremely short light pulse of 0.1 milliseconds to 100 milliseconds. It is characterized in that it can emit extremely intense light as compared to a light source. That is, the flash lamp FL is a pulse light emitting lamp that emits light instantaneously in an extremely short time of less than one second. The light emission time of the flash lamp FL can be adjusted by the coil constant of the lamp power supply that supplies power to the flash lamp FL.

  In addition, the reflector 52 is provided above the plurality of flash lamps FL so as to cover all of them. The basic function of the reflector 52 is to reflect flash light emitted from a plurality of flash lamps FL to the side of the heat treatment space 65. The reflector 52 is formed of an aluminum alloy plate, and its surface (surface facing the flash lamp FL) is roughened by blasting.

  The halogen lamp house 4 provided below the processing chamber 6 incorporates a plurality (40 in this embodiment) of halogen lamps HL inside the housing 41. The plurality of halogen lamps HL perform light irradiation to the heat treatment space 65 from the lower side of the processing chamber 6 through the lower chamber window 64.

  FIG. 9 is a plan view showing the arrangement of a plurality of halogen lamps HL. In the present embodiment, the twenty halogen lamps HL are disposed in upper and lower two stages. Each halogen lamp HL is a rod-shaped lamp having a long cylindrical shape. The upper and lower 20 halogen lamps HL are arranged such that their longitudinal directions are parallel to each other along the main surface of the semiconductor wafer W held by the holder 7 (that is, along the horizontal direction). There is. Therefore, the plane formed by the arrangement of the halogen lamps HL in the upper and lower stages is a horizontal plane.

  Further, as shown in FIG. 9, the disposition density of the halogen lamps HL in the region facing the peripheral portion is higher than the region facing the central portion of the semiconductor wafer W held by the holding portion 7 in both the upper and lower portions. Yes. That is, in both the upper and lower portions, the disposition pitch of the halogen lamps HL is shorter in the peripheral portion than in the central portion of the lamp arrangement. For this reason, it is possible to perform irradiation of a large amount of light to the peripheral portion of the semiconductor wafer W in which a temperature drop is likely to occur at the time of heating by light irradiation from the halogen lamp HL.

  Further, the lamp group composed of the upper halogen lamp HL and the lamp group composed of the lower halogen lamp HL are arranged so as to intersect in a lattice pattern. That is, a total of 40 halogen lamps HL are disposed such that the longitudinal direction of each halogen lamp HL in the upper stage and the longitudinal direction of each halogen lamp HL in the lower stage are orthogonal to each other.

  The halogen lamp HL is a filament-type light source that emits light by making the filament incandescent by energizing the filament disposed inside the glass tube. Inside the glass tube, a gas in which a small amount of a halogen element (iodine, bromine or the like) is introduced into an inert gas such as nitrogen or argon is enclosed. By introducing a halogen element, it is possible to set the temperature of the filament to a high temperature while suppressing the breakage of the filament. Therefore, the halogen lamp HL has a characteristic that it has a long life and can continuously emit strong light as compared with a normal incandescent lamp. That is, the halogen lamp HL is a continuous lighting lamp which emits light continuously for at least one second or more. Further, since the halogen lamp HL is a rod-like lamp, it has a long life, and by arranging the halogen lamp HL in the horizontal direction, the radiation efficiency to the upper semiconductor wafer W becomes excellent.

  A reflector 43 is also provided in the housing 41 of the halogen lamp house 4 below the two-stage halogen lamp HL (FIG. 3). The reflector 43 reflects the light emitted from the plurality of halogen lamps HL to the side of the heat treatment space 65.

  FIG. 10 is a diagram showing the configuration of the reflectance measurement unit 232 provided in the alignment unit 230. As shown in FIG. The reflectance measuring unit 232 includes a light emitting unit 300, a light receiving unit 235, a half mirror 236, and a reflectance calculating unit 31. In the alignment chamber 231 of the alignment unit 230, a rotation support 237 for supporting and rotating the semiconductor wafer W and a rotation motor 238 for rotating the rotation support 237 are provided. The orientation of the semiconductor wafer W is adjusted by rotating the rotary support 237 supporting the semiconductor wafer W by the rotary motor 238.

  The light projector 300 includes a light source such as a halogen light source or an LED light source to emit light for reflectance measurement. The light receiving unit 235 includes a light receiving element that converts the intensity of the received light into an electrical signal. The light emitted from the light emitting unit 300 is reflected by the half mirror 236 and vertically irradiated on the upper surface of the semiconductor wafer W supported by the rotation support unit 237. In the first embodiment, the light emitted from the light emitting unit 300 is irradiated to a portion other than the rotation center of the semiconductor wafer W rotated by the rotation support unit 237. The light emitted from the light emitting unit 300 is reflected on the upper surface of the semiconductor wafer W. The reflected light passes through the half mirror 236 and is received by the light receiving unit 235. The reflectance calculating unit 31 calculates the reflectance of the semiconductor wafer W from the intensity of the light emitted by the light emitting unit 300 and the intensity of the reflected light received by the light receiving unit 235.

  The control unit 3 controls the various operation mechanisms provided in the heat treatment apparatus 100. The hardware configuration of the control unit 3 is the same as that of a general computer. That is, the control unit 3 includes a CPU that is a circuit that performs various arithmetic processing, a ROM that is a read only memory that stores a basic program, a RAM that is a readable and writable memory that stores various information, control software, data, and the like. It has a magnetic disk to be stored. The CPU of the control unit 3 executes a predetermined processing program to advance the processing in the heat treatment apparatus 100. The reflectance calculating unit 31 is a functional processing unit realized by the CPU of the control unit 3 executing a predetermined processing program. Although FIG. 1 shows the control unit 3 in the indexer unit 101, the present invention is not limited to this, and the control unit 3 can be disposed at an arbitrary position in the heat treatment apparatus 100.

  In addition to the above configuration, the thermal processing unit 160 prevents excessive temperature rise of the halogen lamp house 4, the flash lamp house 5, and the processing chamber 6 due to the thermal energy generated from the halogen lamp HL and the flash lamp FL during the heat treatment of the semiconductor wafer W. Therefore, various cooling structures are provided. For example, the wall of the processing chamber 6 is provided with a water cooling pipe (not shown). In addition, the halogen lamp house 4 and the flash lamp house 5 have an air cooling structure in which a gas flow is formed inside and heat is exhausted. Air is also supplied to the gap between the upper chamber window 63 and the lamp light emission window 53 to cool the flash lamp house 5 and the upper chamber window 63.

  Next, the processing operation of the semiconductor wafer W by the heat treatment apparatus 100 according to the present invention will be described. The semiconductor wafer W to be processed is a semiconductor substrate on which a pattern is formed and an impurity (ion) is added by an ion implantation method. The activation of the impurities is performed by flash light irradiation heat treatment (annealing) by the heat treatment apparatus 100. Here, after the rough transfer procedure of the semiconductor wafer W in the heat treatment apparatus 100 is described, the heat treatment of the semiconductor wafer W in the heat treatment unit 160 will be described.

  First, a plurality of unprocessed semiconductor wafers W that have been patterned and implanted with impurities are placed on the load port 110 of the indexer unit 101 while being stored in a carrier C. Then, the delivery robot 120 takes out the unprocessed semiconductor wafers W from the carrier C one by one and loads them into the alignment chamber 231 of the alignment unit 230. In the alignment chamber 231, the direction of the semiconductor wafer W is rotated by rotating the semiconductor wafer W supported by the rotation support portion 237 about the vertical direction axis in the horizontal plane about the central portion as a rotation center and optically detecting a notch or the like. Adjust the

  Further, the orientation of the semiconductor wafer W is adjusted, and the reflectance measurement unit 232 measures the reflectance of the surface of the semiconductor wafer W. The surface of the semiconductor wafer W is a main surface of the semiconductor wafer W on which a pattern is formed and an impurity is implanted. The light emitted from the light emitting unit 300 of the reflectance measuring unit 232 is reflected by the half mirror 236 and irradiated on the surface of the semiconductor wafer W at an incident angle of 0 °. In addition, the light for reflectance measurement emitted from the light emitting unit 300 is applied to the surface of the semiconductor wafer W supported by the rotation support unit 237 and being rotated. Furthermore, the light emitted from the light emitting unit 300 is irradiated on a portion of the surface of the semiconductor wafer W other than the rotation center. The light emitted from the light projector 300 is reflected by the surface of the semiconductor wafer W, and the reflected light is transmitted through the half mirror 236 and received by the light receiver 235. The reflectance calculating unit 31 calculates the reflectance of the surface of the semiconductor wafer W by dividing the intensity of the reflected light from the semiconductor wafer W received by the light receiving unit 235 by the intensity of the light emitted by the light emitting unit 300.

  FIG. 11 is a view schematically showing a reflectance measurement area of the first embodiment. In the first embodiment, since the light emitted from the light emitting unit 300 is irradiated to a portion other than the rotation center of the surface of the rotating semiconductor wafer W, the light is reflected to the annular region 301 on the surface of the semiconductor wafer W The light for rate measurement will be irradiated. Therefore, even if various patterns are formed on the surface of the semiconductor wafer W, the annular region 301 formed of a plurality of portions on the surface of the semiconductor wafer W is irradiated with light for reflectance measurement to be the annular region. Since the reflectance of 301 is to be measured, it is possible to accurately measure the reflectance of the semiconductor wafer W while suppressing the pattern dependency.

  Next, the delivery robot 120 of the indexer unit 101 takes out the semiconductor wafer W whose orientation has been adjusted from the alignment chamber 231, and carries it into the first cool chamber 131 of the cooling unit 130 or the second cool chamber 141 of the cooling unit 140. The unprocessed semiconductor wafer W carried into the first cool chamber 131 or the second cool chamber 141 is carried out by the carrier robot 150 into the carrier chamber 170. When an unprocessed semiconductor wafer W is transferred from the indexer unit 101 to the transfer chamber 170 through the first cool chamber 131 or the second cool chamber 141, the first cool chamber 131 and the second cool chamber 141 are semiconductor wafers W. It acts as a path for the delivery of

  The transfer robot 150 which has taken out the semiconductor wafer W turns so as to face the thermal processing section 160. Subsequently, the gate valve 185 opens the space between the processing chamber 6 and the transfer chamber 170, and the transfer robot 150 carries the unprocessed semiconductor wafer W into the processing chamber 6. At this time, when the preceding heat-treated semiconductor wafer W exists in the processing chamber 6, the semiconductor wafer W after the heat treatment is taken out by one of the transfer hands 151a and 151b, and then an unprocessed semiconductor wafer is obtained. W is carried into the processing chamber 6 to perform wafer replacement. Thereafter, the gate valve 185 closes the space between the processing chamber 6 and the transfer chamber 170.

  The semiconductor wafer W carried into the processing chamber 6 is preheated by the halogen lamp HL, and then flash heat-treated by flash light irradiation from the flash lamp FL. The flash heat treatment activates the impurities.

  After the flash heat treatment is completed, the gate valve 185 opens the space between the processing chamber 6 and the transfer chamber 170 again, and the transfer robot 150 unloads the semiconductor wafer W after the flash heat treatment from the process chamber 6 into the transfer chamber 170. . The transfer robot 150 which has taken out the semiconductor wafer W pivots from the processing chamber 6 toward the first cool chamber 131 or the second cool chamber 141. Further, the gate valve 185 closes the space between the processing chamber 6 and the transfer chamber 170.

  Thereafter, the transfer robot 150 carries the semiconductor wafer W after the heat treatment into the first cool chamber 131 of the cooling unit 130 or the second cool chamber 141 of the cooling unit 140. In the first cool chamber 131 or the second cool chamber 141, a cooling process of the semiconductor wafer W after the flash heating process is performed. Since the temperature of the entire semiconductor wafer W at the time of unloading from the processing chamber 6 of the thermal processing unit 160 is relatively high, it is cooled to near normal temperature by the first cool chamber 131 or the second cool chamber 141. is there. After the predetermined cooling processing time has elapsed, the delivery robot 120 carries out the cooled semiconductor wafer W from the first cool chamber 131 or the second cool chamber 141 and returns it to the carrier C. When a predetermined number of processed semiconductor wafers W are accommodated in the carrier C, the carrier C is unloaded from the load port 110 of the indexer unit 101.

  The description of the flash heat treatment in the heat treatment unit 160 will be continued. Prior to the transfer of the semiconductor wafer W into the processing chamber 6, the valve 84 for air supply is opened, and the valves 89 and 192 for exhaustion are opened to start the supply and exhaust of the inside of the processing chamber 6. When the valve 84 is opened, nitrogen gas is supplied from the gas supply hole 81 to the heat treatment space 65. Further, when the valve 89 is opened, the gas in the processing chamber 6 is exhausted from the gas exhaust hole 86. Thereby, the nitrogen gas supplied from the upper part of the heat treatment space 65 in the processing chamber 6 flows downward, and is exhausted from the lower part of the heat treatment space 65.

  Further, when the valve 192 is opened, the gas in the processing chamber 6 is also exhausted from the transfer opening 66. Furthermore, the atmosphere around the drive unit of the transfer mechanism 10 is also exhausted by an exhaust mechanism (not shown). During the heat treatment of the semiconductor wafer W in the heat treatment unit 160, nitrogen gas is continuously supplied to the heat treatment space 65, and the supply amount thereof is appropriately changed according to the treatment process.

  Subsequently, the gate valve 185 is opened to open the transfer opening 66, and the transfer robot 150 loads the semiconductor wafer W to be processed into the heat treatment space 65 in the processing chamber 6 through the transfer opening 66. The transfer robot 150 advances the transfer hand 151a (or the transfer hand 151b) holding the unprocessed semiconductor wafer W to a position immediately above the holding unit 7 and stops it. Then, when the pair of transfer arms 11 of the transfer mechanism 10 horizontally move from the retracted position to the transfer operation position and ascends, the lift pins 12 protrude from the upper surface of the holding plate 75 of the susceptor 74 through the through holes 79. Semiconductor wafer W. At this time, the lift pin 12 ascends above the upper end of the substrate support pin 77.

  After the unprocessed semiconductor wafer W is placed on the lift pins 12, the transfer robot 150 causes the transfer hand 151 a to withdraw from the heat treatment space 65, and the transfer opening 66 is closed by the gate valve 185. Then, when the pair of transfer arms 11 is lowered, the semiconductor wafer W is transferred from the transfer mechanism 10 to the susceptor 74 of the holding unit 7 and held horizontally from below. The semiconductor wafer W is supported by a plurality of substrate support pins 77 erected on the holding plate 75 and held by the susceptor 74. In addition, the semiconductor wafer W is held by the holding unit 7 with the surface on which the pattern formation is performed and the impurity is implanted as the upper surface. A predetermined distance is formed between the back surface (main surface opposite to the front surface) of the semiconductor wafer W supported by the plurality of substrate support pins 77 and the holding surface 75 a of the holding plate 75. The pair of transfer arms 11 lowered to the lower side of the susceptor 74 is retracted by the horizontal movement mechanism 13 to the retracted position, that is, to the inside of the recess 62.

  After the semiconductor wafer W is held in the horizontal posture by the susceptor 74 of the holding unit 7 from below, the 40 halogen lamps HL are turned on all at once and preheating (assist heating) is started. The halogen light emitted from the halogen lamp HL is transmitted from the lower surface of the semiconductor wafer W through the lower chamber window 64 and the susceptor 74 formed of quartz. The semiconductor wafer W is preheated by receiving light irradiation from the halogen lamp HL, and the temperature rises. In addition, since the transfer arm 11 of the transfer mechanism 10 is retracted to the inside of the concave portion 62, there is no hindrance to the heating by the halogen lamp HL.

  When preheating is performed by the halogen lamp HL, the temperature of the semiconductor wafer W is measured by the radiation thermometer 20. That is, the radiation thermometer 20 receives infrared light radiated from the lower surface of the semiconductor wafer W held by the susceptor 74 through the opening 78, and measures the temperature of the wafer during temperature rise. The measured temperature of the semiconductor wafer W is transmitted to the control unit 3. The control unit 3 controls the output of the halogen lamp HL while monitoring whether or not the temperature of the semiconductor wafer W heated by irradiation of light from the halogen lamp HL has reached a predetermined preheating temperature T1. That is, based on the measurement value of the radiation thermometer 20, the control unit 3 feedback-controls the output of the halogen lamp HL so that the temperature of the semiconductor wafer W becomes the preheating temperature T1. The preheating temperature T1 is set to about 600 ° C. to 800 ° C. (in this embodiment, 700 ° C.) in which there is no fear that the impurity added to the semiconductor wafer W is diffused by heat.

  After the temperature of the semiconductor wafer W reaches the preheating temperature T1, the control unit 3 maintains the semiconductor wafer W at the preheating temperature T1 for a while. Specifically, when the temperature of the semiconductor wafer W measured by the radiation thermometer 20 reaches the preheating temperature T1, the control unit 3 adjusts the output of the halogen lamp HL to substantially reserve the temperature of the semiconductor wafer W. The heating temperature T1 is maintained.

  By performing such preheating by the halogen lamp HL, the entire semiconductor wafer W is uniformly heated to the preheating temperature T1. At the stage of preheating by the halogen lamp HL, the temperature of the peripheral portion of the semiconductor wafer W which is more likely to cause heat radiation tends to be lower than that at the central portion, but the arrangement density of the halogen lamps HL in the halogen lamp house 4 is The region facing the peripheral portion is higher than the region facing the central portion of the semiconductor wafer W. As a result, the amount of light irradiated to the peripheral portion of the semiconductor wafer W that easily dissipates heat increases, and the in-plane temperature distribution of the semiconductor wafer W in the preliminary heating stage can be made uniform.

  When a predetermined time elapses after the temperature of the semiconductor wafer W reaches the preheating temperature T1, the flash lamp FL irradiates the surface of the semiconductor wafer W with flash light. At this time, a part of the flash light emitted from the flash lamp FL goes directly into the processing chamber 6, and the other part is reflected once by the reflector 52 and then goes into the processing chamber 6, and these flash Flash heating of the semiconductor wafer W is performed by light irradiation.

  Since the flash heating is performed by irradiation with flash light (flash light) from the flash lamp FL, the surface temperature of the semiconductor wafer W can be increased in a short time. That is, the flash light emitted from the flash lamp FL has an extremely short irradiation time of 0.1 milliseconds or more and 100 milliseconds or less, in which electrostatic energy previously stored in the capacitor is converted into an extremely short light pulse. It is a strong flashlight. Then, the surface temperature of the semiconductor wafer W flash-heated by the flash light irradiation from the flash lamp FL instantaneously rises to the processing temperature T2 of 1000 ° C. or higher, and the impurity implanted into the semiconductor wafer W is activated. After that, the surface temperature drops rapidly. As described above, since the surface temperature of the semiconductor wafer W can be raised and lowered in an extremely short time, the impurities can be activated while suppressing the diffusion of the impurity implanted into the semiconductor wafer W due to heat. Since the time required for activating the impurity is extremely short compared to the time required for its thermal diffusion, the activation can be performed even for a short time when diffusion of about 0.1 milliseconds to 100 milliseconds does not occur. Complete.

  At the time of flash light irradiation, the light emission intensity of the flash lamp FL is corrected based on the reflectance of the surface of the semiconductor wafer W calculated by the reflectance calculation unit 31. The temperature reached by the surface of the bare wafer when it is irradiated with flash light from the flash lamp FL on a silicon semiconductor wafer (bare wafer) which has not been subjected to patterning and impurity implantation is previously known and known. Also, the reflectance of the surface of the bare wafer is known. Then, based on the ratio between the surface reflectance of the bare wafer and the surface reflectance of the semiconductor wafer W calculated by the reflectance calculating unit 31, the flash lamp FL is controlled so that the surface temperature of the semiconductor wafer W reaches the processing temperature T2. Adjust the charging voltage to the capacitor. As a result, when the semiconductor wafer W to be processed on which a pattern or a film is formed is irradiated with flash light, the surface of the semiconductor wafer W can be accurately heated to the processing temperature T2.

  After the flash heating process is completed, the halogen lamp HL is turned off after a predetermined time has elapsed. Thereby, the semiconductor wafer W is rapidly cooled from the preheating temperature T1. The temperature of the semiconductor wafer W being cooled is measured by the radiation thermometer 20, and the measurement result is transmitted to the control unit 3. The control unit 3 monitors whether the temperature of the semiconductor wafer W has dropped to a predetermined temperature based on the measurement result of the radiation thermometer 20. Then, after the temperature of the semiconductor wafer W is lowered to a predetermined temperature or less, the pair of transfer arms 11 of the transfer mechanism 10 horizontally move from the retracted position to the transfer operation position again and rises, whereby the lift pins 12 are susceptors The semiconductor wafer W after heat treatment is projected from the upper surface of the substrate 74 from the susceptor 74. Subsequently, the transfer opening 66 closed by the gate valve 185 is opened, and the processed semiconductor wafer W placed on the lift pins 12 is carried out by the transfer hand 151 b (or the transfer hand 151 a) of the transfer robot 150. Ru. The transfer robot 150 advances the transfer hand 151 b to a position directly below the semiconductor wafer W pushed up by the lift pins 12 and stops the transfer hand 151 b. Then, the pair of transfer arms 11 is lowered, and the semiconductor wafer W after flash heating is transferred to the transfer hand 151 b and placed thereon. Thereafter, the transfer robot 150 withdraws the transfer hand 151 b from the processing chamber 6 to unload the processed semiconductor wafer W.

  In the first embodiment, the reflectance of the annular region 301 on the surface is measured by irradiating the surface of the rotating semiconductor wafer W with light for reflectance measurement. Therefore, even if various patterns are formed on the surface of the semiconductor wafer W, the reflectance of the annular region 301 composed of a plurality of portions on the surface is to be measured, so that the pattern dependency is suppressed and the semiconductor The reflectance of the wafer W can be measured accurately. As a result, it is possible to accurately adjust the light emission intensity of the flash lamp FL based on the reflectance of the semiconductor wafer W measured by suppressing the pattern dependency.

Second Embodiment
Next, a second embodiment of the present invention will be described. The overall configuration of the heat treatment apparatus 100 of the second embodiment is substantially the same as that of the first embodiment. Further, the processing procedure of the semiconductor wafer W in the heat treatment apparatus 100 of the second embodiment is substantially the same as that of the first embodiment. While the semiconductor wafer W is rotated in the first embodiment to measure the reflectance of the annular region 301 in the reflectance measurement, the semiconductor wafer W is provided with a plurality of light receiving portions in the second embodiment. It is designed to measure the reflectance of multiple points of.

  FIG. 12 is a diagram illustrating a configuration of the reflectance measurement unit 232 according to the second embodiment. In FIG. 12, the same components as those of the first embodiment are denoted by the same reference numerals. The reflectance measurement unit 232 according to the second embodiment includes three light receiving units 235a, 235b, and 235c having different installation positions. The light for reflectance measurement emitted from the light emitting unit 300 is reflected by the half mirror 236 and irradiated to the surface of the semiconductor wafer W supported by the rotation support unit 237. In the second embodiment, light emitted from one light emitting unit 300 and specularly reflected on the surface of the semiconductor wafer W is received by the three light receiving units 235a, 235b, and 235c. Therefore, the reflection positions on the wafer surface of the reflected light received by the three light receiving portions 235a, 235b and 235c are different from each other. That is, the light for reflectance measurement emitted from one light emitting unit 300 receives the reflected light reflected by three different places on the surface of the semiconductor wafer W by the three light receiving units 235a, 235b, and 235c. The reflectance calculating unit 31 calculates the reflectance at each of three reflection positions from the intensity of the light emitted by the light emitting unit 300 and the intensity of the reflected light received by each of the three light receiving units 235a, 235b, and 235c. . Then, the reflectance calculating unit 31 calculates, as the reflectance of the semiconductor wafer W, an average reflectance which is an average value of the reflectances at three locations on the wafer surface.

  The remaining points of the second embodiment except for the reflectance measurement are the same as in the first embodiment. In the second embodiment, the reflectances of the plurality of locations are calculated from the intensities of the reflected light reflected at the plurality of locations on the surface of the semiconductor wafer W, and the average value thereof is calculated as the reflectance of the semiconductor wafer W. There is. Therefore, even if various patterns are formed on the surface of the semiconductor wafer W, the reflectance of the semiconductor wafer W is accurately suppressed by suppressing the pattern dependency since the reflectances of a plurality of places on the surface are measured. It can be measured.

Third Embodiment
Next, a third embodiment of the present invention will be described. The overall configuration of the heat treatment apparatus 100 of the third embodiment is substantially the same as that of the first embodiment. In addition, the processing procedure of the semiconductor wafer W in the heat treatment apparatus 100 of the third embodiment is substantially the same as that of the first embodiment. In the first and second embodiments, the reflectances at a plurality of locations of the semiconductor wafer W are measured. However, in the third embodiment, the scattering component at the specific locations of the semiconductor wafer W is measured.

  FIG. 13 is a diagram showing the configuration of the reflectance measurement unit 232 of the third embodiment. In FIG. 13, the same components as those in the first and second embodiments are given the same reference numerals. The configuration itself of the reflectance measurement unit 232 according to the third embodiment is similar to that according to the second embodiment, and includes three light receiving units 235a, 235b, and 235c having different installation positions. The light for reflectance measurement emitted from the light emitting unit 300 is reflected by the half mirror 236 and irradiated to the surface of the semiconductor wafer W supported by the rotation support unit 237. In the third embodiment, the light received from one light emitting unit 300 and reflected at one specific place on the surface of the semiconductor wafer W is received by the three light receiving units 235a, 235b, and 235c. That is, the reflection positions on the wafer surface of the reflected light received by the three light receiving portions 235a, 235b, and 235c are common. In the third embodiment, as shown in FIG. 13, the light for reflectance measurement emitted from the light emitting unit 300 is not specularly reflected on the surface of the semiconductor wafer W from the macroscopic viewpoint and is scattered at the specific location. It is Such a phenomenon occurs, for example, when a three-dimensional pattern is formed on the surface of the semiconductor wafer W. In addition, since such a scattering phenomenon can occur in all locations where a three-dimensional pattern or the like is formed, the specific location of the semiconductor wafer W does not mean a fixed location on the wafer surface, but any one of them. It is a place.

  In the third embodiment, the light for reflectance measurement irradiated from one light projecting unit 300 is reflected by three light receiving units 235a, which are reflected at different angles at specific locations on the surface of the semiconductor wafer W. Light is received by 235b and 235c. The reflectance calculating unit 31 adds a scattering component to the reflectance of the specific portion from the intensity of the light emitted by the light emitting unit 300 and the intensity of the reflected light received by each of the three light receiving units 235a, 235b, and 235c. Also measure.

  The remaining points of the third embodiment excluding the reflectance measurement are the same as in the first embodiment. In the third embodiment, the scattered component is also measured in addition to the reflectance of the specific location from the intensities of the plurality of reflected lights reflected at different angles at specific locations on the surface of the semiconductor wafer W. Therefore, even if a three-dimensional pattern is formed on the surface of the semiconductor wafer W, the scattering component of a specific part of the surface is also measured, so the pattern dependency is suppressed and the reflectance of the semiconductor wafer W is accurate. Can be measured.

<Modification>
Although the embodiments of the present invention have been described above, various modifications can be made to the present invention other than those described above without departing from the scope of the present invention. For example, in the first embodiment, a plurality of light emitting units 300 for irradiating light for reflectance measurement to a plurality of portions having different distances from the rotation center of the semiconductor wafer W are provided, and a plurality of annular regions having different diameters. It is also possible to measure the reflectance of If the average value of the reflectances of a plurality of annular regions having different diameters is calculated, it is possible to accurately measure the reflectance of the semiconductor wafer W while suppressing the pattern dependency more.

  In the first embodiment, the reflectance of the annular region 301 is measured. However, the present invention is not limited to this, and the reflectance of the arc-shaped region is set so that the rotation angle of the semiconductor wafer W is less than 360 °. May be measured. Even in this case, the reflectance of the arc-shaped area formed of a plurality of portions on the surface of the semiconductor wafer W is to be measured, so that the reflectance of the semiconductor wafer W can be accurately measured by suppressing the pattern dependency. it can.

  Further, in the first embodiment, the semiconductor wafer W is rotated with respect to the fixed light projecting unit 300. On the contrary, the semiconductor wafer W in a stationary state or rotated is used for measuring the reflectance. Light may be scanned. Furthermore, the semiconductor wafer W may be moved linearly with respect to the light emitting unit 300, for example. That is, the semiconductor wafer W may be moved relative to the light for reflectance measurement emitted from the light emitting unit 300.

  In the second embodiment, the average value of the reflectance at a plurality of locations on the semiconductor wafer W is calculated, but it is not always necessary to calculate the average value. When the average value is not calculated, the intensity of the light irradiated to each of the plurality of locations from the flash lamp FL may be adjusted based on the measured reflectances of the plurality of locations. For example, based on the reflectance of the peripheral portion of the semiconductor wafer W, the intensity of light irradiated to the peripheral portion of the semiconductor wafer W from the flash lamps FL arranged at the end of the array of the plurality of flash lamps FL is adjusted You should do it. In this way, based on the measured reflectance of the semiconductor wafer W, the emission intensity of the flash lamp FL can be adjusted so that the in-plane temperature distribution of the semiconductor wafer W becomes more uniform.

  In the second embodiment, the average reflectance at three locations may be calculated from the intensity of the combined reflected light obtained by combining the reflected light received by the three light receivers 235a, 235b, and 235c by an optical fiber.

  In the second and third embodiments, the number of light receiving parts is not limited to three, and may be two or more.

  In the above embodiment, the flash lamp house 5 is provided with 30 flash lamps FL. However, the present invention is not limited to this, and the number of flash lamps FL can be any number. . Further, the flash lamp FL is not limited to the xenon flash lamp, and may be a krypton flash lamp. Further, the number of halogen lamps HL provided in the halogen lamp house 4 is not limited to 40, and can be an arbitrary number.

  Further, in the above embodiment, the preheating of the semiconductor wafer W is performed using the filament-type halogen lamp HL as a continuous lighting lamp that continuously emits light for 1 second or longer, but is not limited thereto. Instead of the halogen lamp HL, a pre-heating may be performed using a discharge arc lamp (for example, a xenon arc lamp) as a continuous lighting lamp. Alternatively, a susceptor for holding the semiconductor wafer W may be placed on a hot plate, and the semiconductor wafer W may be preheated by thermal conduction from the hot plate.

  The substrate to be processed by the heat treatment apparatus 100 is not limited to a semiconductor wafer, and may be a glass substrate or a solar cell substrate used for a flat panel display such as a liquid crystal display device. Further, the technique according to the present invention may be applied to heat treatment of a high dielectric constant gate insulating film (High-k film), bonding of metal and silicon, or crystallization of polysilicon.

Reference Signs List 3 control unit 4 halogen lamp house 5 flash lamp house 6 processing chamber 7 holding unit 10 transfer mechanism 31 reflectance calculation unit 65 heat treatment space 100 heat treatment space 101 indexer unit 130, 140 cooling unit 150 transfer robot 160 heat treatment unit 230 alignment unit 231 Alignment chamber 232 Reflectivity measurement unit 235, 235a, 235b, 235c Light receiving unit 300 Light emitting unit FL Flash lamp HL Halogen lamp W Semiconductor wafer

Claims (12)

A heat treatment apparatus for heating a substrate by irradiating the substrate with light,
A heating lamp which heats the substrate by irradiating the substrate with light;
A rotary support unit for supporting and rotating the substrate;
A light projecting unit that emits light for measuring reflectance to a site other than the rotation center of the substrate rotated by the rotation supporting unit;
A light receiving unit that receives light reflected by the substrate and light emitted from the light emitting unit;
A reflectance calculating unit configured to calculate the reflectance of the substrate from the intensity of the light emitted by the light emitting unit and the intensity of the reflected light received by the light receiving unit;
A heat treatment apparatus comprising: In the heat treatment apparatus according to claim 1,
What is claimed is: 1. A heat treatment apparatus comprising: a plurality of light projection units for irradiating light for reflectance measurement to a plurality of portions having different distances from the rotation center of the substrate. A heat treatment apparatus for heating a substrate by irradiating the substrate with light,
A heating lamp which heats the substrate by irradiating the substrate with light;
A light emitting unit for irradiating the substrate with light for reflectance measurement;
A plurality of light receiving units for receiving light reflected from the light projecting unit reflected by the plurality of portions of the substrate;
A reflectance calculating unit that calculates the reflectance of the plurality of portions of the substrate from the intensity of the light emitted by the light emitting unit and the intensity of the reflected light received by the plurality of light receiving units;
A heat treatment apparatus comprising: In the heat treatment apparatus according to claim 3,
The said reflectance calculation part calculates the average reflectance which is an average value of the reflectance of these several places, The heat processing apparatus characterized by the above-mentioned. In the heat treatment apparatus according to claim 3,
A heat treatment apparatus characterized by adjusting the intensity of light emitted from the heating lamp to the plurality of locations based on the reflectances of the plurality of locations calculated by the reflectance calculation unit. A heat treatment apparatus for heating a substrate by irradiating the substrate with light,
A heating lamp which heats the substrate by irradiating the substrate with light;
A light emitting unit for irradiating the substrate with light for reflectance measurement;
A plurality of light receiving units for receiving the light emitted from the light projecting unit and reflected by the specific portion of the substrate;
A reflectance calculating unit that calculates the reflectance of the specific portion of the substrate from the intensity of the light emitted by the light emitting unit and the intensity of the reflected light received by the plurality of light receiving units;
A heat treatment apparatus comprising: A heat treatment method of heating a substrate by irradiating the substrate with light,
Heating the substrate by irradiating the substrate with light from a heating lamp;
Irradiating a portion of the substrate other than the center of rotation of the substrate to be rotated with light for reflectance measurement;
A light receiving step of receiving light reflected by the substrate from the light irradiated in the irradiating step;
A reflectance calculation step of calculating the reflectance of the substrate from the intensity of the light irradiated in the irradiation step and the intensity of the reflected light received in the light reception step;
A heat treatment method comprising: In the heat treatment method according to claim 7,
In the irradiation step, a plurality of portions having different distances from the center of rotation of the substrate are irradiated with light for reflectance measurement. A heat treatment method of heating a substrate by irradiating the substrate with light,
Heating the substrate by irradiating the substrate with light from a heating lamp;
An irradiation step of irradiating the substrate with light for reflectance measurement;
A light receiving step of receiving, by a plurality of light receiving units, light reflected in the plurality of locations of the substrate and light reflected in the irradiation step;
A reflectance calculation step of calculating the reflectance of the plurality of portions of the substrate from the intensity of the light irradiated in the irradiation step and the intensity of the reflected light received by the plurality of light receiving portions in the light receiving step;
A heat treatment method comprising: In the heat treatment method according to claim 9,
In the reflectance calculating step, an average reflectance, which is an average value of the reflectances of the plurality of places, is calculated. In the heat treatment method according to claim 9,
A heat treatment method comprising adjusting the intensity of light irradiated to the plurality of locations from the heating lamp in the heating step based on the reflectances of the plurality of locations calculated in the reflectance calculation step. A heat treatment method of heating a substrate by irradiating the substrate with light,
Heating the substrate by irradiating the substrate with light from a heating lamp;
An irradiation step of irradiating the substrate with light for reflectance measurement;
A light receiving step of receiving light reflected in the specific part of the substrate by the plurality of light receiving parts, the light irradiated in the irradiating step;
A reflectance calculation step of calculating the reflectance of the specific portion of the substrate from the intensity of light irradiated in the irradiation step and the intensity of reflected light received by the plurality of light receiving portions in the light receiving step;
A heat treatment method comprising:

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