JP6975687B2 - Heat treatment equipment - Google Patents

Description

The present invention is a thin plate precision electronic substrate such as a semiconductor wafer (hereinafter, simply referred to as "substrate") relates to a heat treatment equipment for heating the substrate to by irradiating flash light.

In the process of manufacturing semiconductor devices, flash lamp annealing (FLA), which heats a semiconductor wafer in an extremely short time, has attracted attention. Flash lamp annealing uses a xenon flash lamp (hereinafter, simply referred to as "flash lamp" to mean a xenon flash lamp) to irradiate the surface of the semiconductor wafer with flash light, thereby making only the surface of the semiconductor wafer extremely. This is a heat treatment technology that raises the temperature in a short time (several milliseconds or less).

The radiation spectral distribution of the xenon flash lamp is from the ultraviolet region to the near infrared region, and the wavelength is shorter than that of the conventional halogen lamp, which is almost the same as the basic absorption band of the silicon semiconductor wafer. Therefore, when the semiconductor wafer is irradiated with the flash light from the xenon flash lamp, the transmitted light is small and the temperature of the semiconductor wafer can be rapidly raised. It has also been found that if the flash light is irradiated for an extremely short time of several milliseconds or less, the temperature can be selectively raised only in the vicinity of the surface of the semiconductor wafer.

Such flash lamp annealing is utilized for processes that require very short heating times, such as activation of impurities typically injected into semiconductor wafers. By irradiating the surface of a semiconductor wafer into which impurities have been implanted by the ion implantation method with flash light from a flash lamp, the surface of the semiconductor wafer can be raised to the activation temperature for a very short time, and the impurities are deeply diffused. Only impurity activation can be performed without causing it.

In flash lamp annealing, since the temperature of the semiconductor wafer is instantaneously raised by irradiating the flash light having an extremely short irradiation time, it is not possible to feedback control the emission intensity of the flash lamp in real time while measuring the wafer temperature. Therefore, it is necessary to adjust the emission intensity of the flash lamp in advance so that the surface of the semiconductor wafer is appropriately heated to a predetermined target temperature. Patent Document 1 discloses a technique of measuring the reflectance of a semiconductor wafer to be processed before heat treatment and calculating the voltage applied to the flash lamp based on the measured reflectance. In the technique disclosed in Patent Document 1, the reflectance of the semiconductor wafer is measured before the semiconductor wafer is carried into the processing chamber to be irradiated with the flash light.

Japanese Unexamined Patent Publication No. 2011-204741

By the way, the reflectance of a semiconductor wafer differs depending on the properties of the wafer surface and the film formed on the wafer surface. Therefore, it is possible to check in advance that a non-standard semiconductor wafer is carried in by measuring the reflectance of the semiconductor wafer before carrying it into the processing chamber. However, in the past, since the reflectance of the semiconductor wafer was only measured before the semiconductor wafer was carried into the processing chamber, it was not possible to confirm by the reflectance measurement whether the normal heat treatment was performed. ..

The present invention has been made in view of the above problems, and an object thereof is to provide a heat treatment equipment which can confirm whether a normal heating process is performed easily.

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 flash light, in which a processing chamber accommodating the substrate and the substrate accommodated in the processing chamber are provided. A flash lamp that irradiates and heats the flash light, a reflectance measuring unit that measures the reflectance of the substrate after being heated by the flash light irradiation from the flash lamp, and an untreated substrate are carried into the apparatus. The present invention includes an indexer unit for carrying the processed substrate out of the apparatus, and the reflectance measuring unit is provided in a transfer path of the substrate from the processing chamber to the indexer unit .

The invention of claim 2 is characterized in that, in the heat treatment apparatus according to the invention of claim 1, the reflectance measuring unit also measures the reflectance of the substrate before irradiating the flash light from the flash lamp. do.

Further, according to the third aspect of the present invention, in the heat treatment apparatus according to the first or second aspect , a cooling chamber for cooling the heated substrate is installed in the transport path, and the reflectivity measuring unit is used. It is characterized in that it is provided in the cooling chamber.

Further, the invention of claim 4 is a heat treatment apparatus according to any one of claims 1 to 3 , based on the reflectance of the substrate measured by the reflectance measuring unit. Further, a determination unit for determining whether or not the heat treatment is normally performed, and a warning issuing unit for issuing a warning when the determination unit determines that the heat treatment of the substrate is not normally performed. It is characterized by being prepared.

Further, the invention of claim 5 further includes a storage unit for storing the reflectance of the substrate measured by the reflectance measuring unit in the heat treatment apparatus according to any one of claims 1 to 4. It is characterized by.

Further, the invention of claim 6 is to adjust the light emission intensity of the flash lamp by artificial intelligence based on the reflectance of a plurality of substrates accumulated in the storage unit in the heat treatment apparatus according to the invention of claim 5. It is a feature.

Further, in the invention of claim 7, in the heat treatment apparatus according to any one of claims 1 to 6 , the substrate is irradiated with light to perform preheating before irradiating the flash light from the flash lamp. It is characterized by further providing a continuous lighting lamp.

According to the inventions of claims 1 to 7 , in order to measure the reflectance of the substrate after being heated by the flash light irradiation from the flash lamp, a normal heat treatment is performed based on the reflectance of the substrate after the heating. Can be easily confirmed if has been performed.

In particular, according to the invention of claim 6 , since the light emission intensity of the flash lamp is adjusted by artificial intelligence based on the reflectance of a plurality of substrates accumulated in the storage unit, the reflectance of the substrate after heating is also taken into consideration. The emission intensity of the flash lamp can be adjusted to an appropriate value.

It is a top view which shows the heat treatment apparatus which concerns on this invention. It is a front view of the heat treatment apparatus of FIG. It is a vertical sectional view which shows the structure of the heat treatment part. It is a perspective view which shows the whole appearance of a holding part. It is a top view of the susceptor. It is sectional drawing of the susceptor. It is a top view of the transfer mechanism. It is a side view of the transfer mechanism. It is a top view which shows the arrangement of a plurality of halogen lamps. It is a functional block diagram of the control part of a heat treatment apparatus.

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

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 the 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 that irradiates a disk-shaped semiconductor wafer W as a substrate with flash light to heat the semiconductor wafer W. The size of the semiconductor wafer W to be processed is not particularly limited, but is, for example, φ300 mm or φ450 mm. Impurities are injected into the semiconductor wafer W before being carried into the heat treatment apparatus 100, and the activation treatment of the impurities injected by the heat treatment by the heat treatment apparatus 100 is executed. In addition, in FIG. 1 and each subsequent drawing, the dimensions and numbers of each part are exaggerated or simplified as necessary for easy understanding. Further, in each of FIGS. 1 to 3, an XYZ Cartesian coordinate system is provided in which the Z-axis direction is the vertical direction and the XY plane is the horizontal plane in order to clarify the directional relationship between them.

As shown in FIGS. 1 and 2, in the heat treatment apparatus 100, the indexer unit 101 for carrying the unprocessed semiconductor wafer W into the apparatus from the outside and carrying the processed semiconductor wafer W out of the apparatus, unprocessed. Alignment unit 230 for positioning the semiconductor wafer W, two cooling units 130 and 140 for cooling the semiconductor wafer W after heat treatment, heat treatment unit 160 for flash heat treatment of the semiconductor wafer W, and cooling units 130 and 140. A transfer robot 150 that transfers the semiconductor wafer W to the heat treatment unit 160 is provided. Further, the heat treatment apparatus 100 includes a control unit 3 that controls the operation mechanism provided in each of the above processing units and the transfer robot 150 to advance the flash heat treatment of the semiconductor wafer W.

The indexer unit 101 takes out a load port 110 on which a plurality of carriers C (two in this embodiment) are placed side by side, an unprocessed semiconductor wafer W from each carrier C, and a semiconductor wafer processed on each carrier C. It is equipped with a delivery robot 120 that stores W. The carrier C accommodating the unprocessed semiconductor wafer W is transported by an automatic guided vehicle (AGV, OHT) or the like and mounted on the load port 110, and the carrier C accommodating the processed semiconductor wafer W is an automatic guided vehicle. 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 the arrow CU in FIG. 2 so that the delivery robot 120 can load and unload an arbitrary semiconductor wafer W with respect to the carrier C. ing. As the form of the carrier C, in addition to the FOUP (front opening unified pod) for storing the semiconductor wafer W in a closed space, the SMIF (Standard Mechanical Inter Face) pod and the OC (open) for exposing the stored semiconductor wafer W to the outside air. cassette) may be used.

Further, the delivery robot 120 is capable of a slide movement as shown by the arrow 120S in FIG. 1, a turning operation and an ascending / descending operation as shown by the arrow 120R. As a result, the delivery robot 120 transfers the semiconductor wafer W to and from the two carriers C, and also transfers the semiconductor wafer W to the alignment unit 230 and the two cooling units 130 and 140. The semiconductor wafer W is moved in and out of the carrier C by the delivery robot 120 by sliding the hand 121 and moving the carrier C up and down. Further, the transfer of the semiconductor wafer W between the delivery robot 120 and the alignment unit 230 or the cooling units 130, 140 is performed by the slide movement of the hand 121 and the elevating operation of the delivery robot 120.

The alignment portion 230 is provided so as to be connected to the side of the indexer portion 101 along the Y-axis direction. The alignment unit 230 is a processing unit that rotates the semiconductor wafer W in a horizontal plane and directs the semiconductor wafer W in an appropriate direction for flash heating. The alignment portion 230 includes a mechanism for supporting and rotating the semiconductor wafer W in a horizontal posture inside the alignment chamber 231 which is a housing made of an aluminum alloy, and a notch, an orifra, etc. formed on the peripheral portion of the semiconductor wafer W. It is configured by providing a mechanism for optically detecting the above (all not shown).

The delivery of the semiconductor wafer W to the alignment unit 230 is performed by the delivery robot 120. The semiconductor wafer W is passed from the delivery robot 120 to the alignment chamber 231 so that the center of the wafer is located at a predetermined position. In the alignment unit 230, the semiconductor wafer W is rotated around the vertical axis around the center of the semiconductor wafer W received from the indexer unit 101, and the orientation of the semiconductor wafer W is adjusted by optically detecting a notch or the like. do. The semiconductor wafer W whose orientation has been adjusted is taken out from the alignment chamber 231 by the delivery robot 120.

A transfer chamber 170 for accommodating 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 heat treatment section 160, the first cool chamber 131 of the cooling section 130, and the second cool chamber 141 of the cooling section 140 are connected to each other on three sides of the transfer chamber 170.

The heat treatment unit 160, which is the main part of the heat treatment apparatus 100, is a substrate processing unit that irradiates a preheated semiconductor wafer W with a flash (flash light) from a xenon flash lamp FL to perform a flash heat treatment. The detailed configuration of the heat treatment unit 160 will be further described later.

The two cooling units 130 and 140 have substantially the same configuration. The cooling units 130 and 140 are provided with a metal cooling plate and a quartz plate placed on the upper surface thereof inside the first cool chamber 131 and the second cool chamber 141, which are aluminum alloy housings, respectively. (Both are not shown). The cooling plate is temperature-controlled to room temperature (about 23 ° C.) by a Perche element or a constant temperature water circulation. The semiconductor wafer W that has been subjected to the flash heat treatment by the heat treatment 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 to both of the indexer unit 101 and the transfer chamber 170. The first cool chamber 131 and the second cool chamber 141 are provided with two openings for carrying in and out the semiconductor wafer W. 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 portion 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. Further, 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 becomes a closed space.

Further, of the two openings of the second cool chamber 141, the opening connected to the indexer portion 101 can be opened and closed by the 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 portion 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. Further, 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 becomes a closed space.

Further, in the first cool chamber 131 and the second cool chamber 141, the reflectance measuring unit 135 for measuring the reflectance of the surface of the semiconductor wafer W placed and supported on the above-mentioned quartz plate and the reflectance measurement are measured, respectively. A portion 145 is provided. Both the reflectance measuring units 135 and 145 irradiate the surface of the semiconductor wafer W with light and receive the reflected light reflected on the surface, and the semiconductor is based on the intensity of the irradiated light and the intensity of the received reflected light. The reflectance of the surface of the wafer W is measured. More specifically, the reflectance measuring units 135 and 145 calculate the reflectance of the semiconductor wafer W by dividing the intensity of the received reflected light by the intensity of the irradiated light.

Further, the cooling units 130 and 140 are provided with a gas supply mechanism for supplying clean nitrogen gas to the first cool chamber 131 and the second cool chamber 141, and an exhaust mechanism for exhausting the atmosphere in the chamber, respectively. These gas supply mechanism and exhaust mechanism may be capable of switching the flow rate in two stages. Further, nitrogen gas is also supplied from the gas supply unit to the transfer chamber 170 and the alignment chamber 231 and the atmosphere inside them is exhausted by the exhaust unit.

The transfer robot 150 provided in the transfer chamber 170 is capable of turning around an axis along the vertical direction as shown by an arrow 150R. The transfer robot 150 has two link mechanisms composed 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, respectively. These transport hands 151a and 151b are vertically spaced apart by a predetermined pitch, and are independently slidable in the same horizontal direction by a link mechanism. Further, the transfer robot 150 moves the two transfer hands 151a and 151b up and down while keeping them separated by a predetermined pitch by moving the base provided with the two link mechanisms up and down.

When the transfer robot 150 transfers (puts in and out) the semiconductor wafer W as a transfer partner for the first cool chamber 131, the second cool chamber 141, or the processing chamber 6 of the heat treatment unit 160, first, both transfer hands 151a and 151b It is located at a height at which one of the transfer hands transfers the semiconductor wafer W with the transfer partner by turning so as to face the delivery partner and then moving up and down (or while turning). Then, the transfer hand 151a (151b) is slid linearly in the horizontal direction to transfer the semiconductor wafer W to the transfer partner.

The semiconductor wafer W can be delivered between the transfer robot 150 and the delivery robot 120 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 path for transferring the semiconductor wafer W between the transfer robot 150 and the delivery robot 120. .. Specifically, the semiconductor wafer W is delivered when one of the transfer robot 150 or the delivery robot 120 receives the semiconductor wafer W passed to the first cool chamber 131 or the second cool chamber 141 by the other.

As described above, gate valves 181 and 182 are provided between the first cool chamber 131 and the second cool chamber 141 and the indexer portion 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. Further, a gate valve 185 is provided between the transfer chamber 170 and the processing chamber 6 of the heat treatment unit 160. When the semiconductor wafer W is conveyed in the heat treatment apparatus 100, these gate valves are opened and closed as appropriate.

Next, the configuration of the heat treatment unit 160 will be described. FIG. 3 is a vertical sectional view showing the configuration of the heat treatment unit 160. The heat treatment unit 160 includes a processing chamber 6 that accommodates the semiconductor wafer W and performs heat treatment, a flash lamp house 5 that incorporates a plurality of flash lamp FLs, and a halogen lamp house 4 that incorporates a plurality of halogen lamps HL. Be prepared. A flash lamp house 5 is provided on the upper side of the processing chamber 6, and a halogen lamp house 4 is provided on the lower side. Further, the heat treatment unit 160 is a transfer mechanism 10 that transfers the semiconductor wafer W between the holding unit 7 that holds the semiconductor wafer W in a horizontal posture and the holding unit 7 and the transfer robot 150 inside the processing chamber 6. And.

The processing chamber 6 is configured by mounting quartz chamber windows above and below the cylindrical chamber side portion 61. The chamber side portion 61 has a substantially tubular shape with upper and lower openings, and the upper chamber window 63 is attached to the upper opening and closed, and the lower chamber window 64 is attached to the lower opening 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 through which the flash light emitted from the flash lamp FL is transmitted into the processing chamber 6. Further, the lower chamber window 64 constituting the floor portion of the processing chamber 6 is also a disk-shaped member formed of quartz, and functions as a quartz window that transmits light from the halogen lamp HL into the processing chamber 6.

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

By mounting the reflective rings 68 and 69 on 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 is formed which is surrounded by the central portion of the inner wall surface of the chamber side portion 61 to which the reflection rings 68 and 69 are not attached, the lower end surface of the reflection ring 68, and the upper end surface of the reflection ring 69. .. 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 portion 7 that holds the semiconductor wafer W. The chamber side 61 and the reflective rings 68, 69 are made of a metal material (for example, stainless steel) having excellent strength and heat resistance.

Further, the chamber side portion 61 is provided with a transport opening (furnace port) 66 for loading and unloading the semiconductor wafer W into and out of the processing chamber 6. The transport opening 66 can be opened and closed by a gate valve 185. The transport opening 66 is communicated with the outer peripheral surface of the recess 62. Therefore, when the gate valve 185 opens the transport opening 66, the semiconductor wafer W is carried in from the transport opening 66 through the recess 62 into the heat treatment space 65 and the semiconductor wafer W is carried out from the heat treatment space 65. It can be performed. Further, when the gate valve 185 closes the transport opening 66, the heat treatment space 65 in the processing chamber 6 becomes a closed space.

Further, a gas supply hole 81 for supplying the processing gas to the heat treatment space 65 is formed in the upper part of the 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 communicated with 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 inserted 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 processing gas that has flowed into the buffer space 82 flows so as to expand in the buffer space 82 having a smaller fluid resistance than the gas supply hole 81, and is supplied from the gas supply hole 81 into the heat treatment space 65. As the treatment 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 (nitrogen in this embodiment).

On the other hand, a gas exhaust hole 86 for exhausting the gas in the heat treatment space 65 is formed in the lower part of the inner wall of the processing chamber 6. The gas exhaust hole 86 is formed at a position below 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 in an annular shape 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 inserted 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 discharged from the gas exhaust hole 86 to the gas exhaust pipe 88 via the buffer space 87. 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. Further, 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 in which the heat treatment apparatus 100 is installed.

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

FIG. 4 is a perspective view showing the overall appearance of the holding portion 7. The holding portion 7 includes a base ring 71, a connecting portion 72, and a susceptor 74. The base ring 71, the connecting portion 72 and the susceptor 74 are all made of quartz. That is, the entire holding portion 7 is made of quartz.

The base ring 71 is an arc-shaped quartz member in which a part is 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. By placing the base ring 71 on the bottom surface of the recess 62, the base ring 71 is supported on the wall surface of the processing chamber 6 (see FIG. 3). A plurality of connecting portions 72 (four in this embodiment) are erected on the upper surface of the base ring 71 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. Further, FIG. 6 is a cross-sectional view of the susceptor 74. 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 plate-shaped 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 upper peripheral edge 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 circumference of the guide ring 76 is a tapered surface that widens upward from the holding plate 75. The guide ring 76 is made 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 of the upper surface of the holding plate 75 inside the guide ring 76 is a planar holding surface 75a for holding the semiconductor wafer W. A plurality of substrate support pins 77 are erected on the holding surface 75a of the holding plate 75. In the present embodiment, a total of 12 substrate support pins 77 are erected at every 30 ° along the circumference of the outer peripheral circle (inner peripheral circle of the guide ring 76) of the holding surface 75a and the concentric circle. The diameter of the circle in which the 12 substrate support pins 77 are arranged (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, the diameter is φ270 mm to φ280 mm (this implementation). In the form, it is φ270 mm). Each substrate support pin 77 is made 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 edge 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 holding portion 7 on the wall surface of the processing chamber 6, the holding portion 7 is mounted on the processing chamber 6. When the holding portion 7 is mounted on 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 plane.

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 portion 7 mounted on 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 precisely, the upper ends of the 12 substrate support pins 77 come into contact with the lower surface of the semiconductor wafer W to support the semiconductor wafer W. Since the heights of the 12 substrate support pins 77 (distance from the upper end of the substrate support pins 77 to the holding surface 75a of the holding plate 75) are uniform, the semiconductor wafer W is placed in a horizontal position by the 12 substrate support pins 77. Can be supported.

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

Further, as shown in FIGS. 4 and 5, an opening 78 is formed in the holding plate 75 of the susceptor 74 so as to penetrate vertically. The opening 78 is provided for the radiation thermometer 20 (see FIG. 3) to receive synchrotron radiation (infrared light) emitted from the lower surface of the semiconductor wafer W held by the susceptor 74. That is, the radiation thermometer 20 receives the light radiated 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. Further, the holding plate 75 of the susceptor 74 is provided with four through holes 79 through which the lift pin 12 of the transfer mechanism 10 described later penetrates for the transfer of the semiconductor wafer W.

FIG. 7 is a plan view of the transfer mechanism 10. Further, 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 that generally follows the 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 has a transfer operation position (solid line position in FIG. 7) for transferring the semiconductor wafer W to the holding portion 7 and the semiconductor wafer W held by the holding portion 7. It is horizontally moved to and from the retracted position (the two-point chain line position in FIG. 7) that does not overlap in a plan view. The horizontal movement mechanism 13 may be one in which each transfer arm 11 is rotated by an individual motor, or a pair of transfer arms 11 are interlocked and rotated by one motor using a link mechanism. It may be something to move.

Further, the pair of transfer arms 11 are moved up and down together with the horizontal movement mechanism 13 by the elevating mechanism 14. When the elevating mechanism 14 raises 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) drilled in the susceptor 74, and the lift pins The upper end of 12 protrudes from the upper surface of the susceptor 74. On the other hand, when the elevating mechanism 14 lowers the pair of transfer arms 11 at the transfer operation position, the lift pin 12 is pulled out from the through hole 79, and the horizontal movement mechanism 13 moves the pair of transfer arms 11 so as to open each. The transfer arm 11 moves to the retracted position. The retracted position of the pair of transfer arms 11 is directly above the base ring 71 of the holding portion 7. Since the base ring 71 is placed 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 also provided in the vicinity of the portion where the drive unit (horizontal movement mechanism 13 and elevating mechanism 14) of the transfer mechanism 10 is provided, and the atmosphere around the drive unit of the transfer mechanism 10 is provided. Is configured to be discharged to the outside of the processing chamber 6.

Returning to FIG. 3, the flash lamp house 5 provided above the processing chamber 6 has a light source composed of a plurality of (30 in this embodiment) xenon flash lamp FL inside the housing 51, and the light source thereof. It is configured to include a reflector 52 provided so as to cover the upper part. Further, a lamp light emitting window 53 is attached to the bottom of the housing 51 of the flash lamp house 5. The lamp light emitting window 53 constituting the floor of the flash lamp house 5 is a plate-shaped quartz window made of quartz. By installing the flash lamp house 5 above the processing chamber 6, the lamp light emitting 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 their respective longitudinal directions are along the main surface of the semiconductor wafer W held by the holding portion 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 lamp FL is also a horizontal plane.

The xenon flash lamp FL is provided on a rod-shaped glass tube (discharge tube) in which xenon gas is sealed inside and an anode and a cathode connected to a condenser are arranged at both ends thereof, and on the outer peripheral surface of the glass tube. It is equipped with a cathode electrode. Since xenon gas is electrically an insulator, electricity does not flow in the glass tube under normal conditions even if electric charges are accumulated in the condenser. However, when a high voltage is applied to the trigger electrode to break the insulation, the electricity stored in the capacitor instantly flows into the glass tube, and the light is emitted by the excitation of the xenon atom or molecule at that time. In such a xenon flash lamp FL, the electrostatic energy stored in the capacitor in advance is converted into an extremely short optical pulse of 0.1 millisecond to 100 millisecond, so that the halogen lamp HL is continuously lit. It has the feature that it can irradiate extremely strong light compared to a light source. That is, the flash lamp FL is a pulsed light emitting lamp that instantaneously emits light in an extremely short time of less than 1 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.

Further, 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 the flash light emitted from the plurality of flash lamps FL toward the heat treatment space 65. The reflector 52 is made of an aluminum alloy plate, and its surface (the surface facing the flash lamp FL) is roughened by blasting.

The halogen lamp house 4 provided below the processing chamber 6 contains a plurality of halogen lamps HL (40 in this embodiment) inside the housing 41. The plurality of halogen lamps HL irradiate the heat treatment space 65 with light from below 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 this embodiment, 20 halogen lamps HL are arranged in each of the upper and lower two stages. Each halogen lamp HL is a rod-shaped lamp having a long cylindrical shape. The 20 halogen lamps HL in both the upper and lower stages are arranged so that their longitudinal directions are parallel to each other along the main surface of the semiconductor wafer W held by the holding portion 7 (that is, along the horizontal direction). There is. Therefore, the plane formed by the arrangement of the halogen lamps HL in both the upper and lower stages is a horizontal plane.

Further, as shown in FIG. 9, the arrangement density of the halogen lamp HL in the region facing the peripheral edge 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 stages. There is. That is, in both the upper and lower stages, the arrangement pitch of the halogen lamp HL is shorter in the peripheral portion than in the central portion of the lamp arrangement. Therefore, it is possible to irradiate a peripheral portion of the semiconductor wafer W, which tends to have a temperature drop during heating by light irradiation from the halogen lamp HL, with a larger amount of light.

Further, the lamp group consisting of the halogen lamp HL in the upper stage and the lamp group consisting of the halogen lamp HL in the lower stage are arranged so as to intersect in a grid pattern. That is, a total of 40 halogen lamps HL are arranged so 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 incandescentizes the filament and emits light by energizing the filament arranged inside the glass tube. Inside the glass tube, a gas in which a trace amount of a halogen element (iodine, bromine, etc.) is introduced into an inert gas such as nitrogen or argon is enclosed. By introducing the halogen element, it becomes 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 longer life than a normal incandescent lamp and can continuously irradiate strong light. That is, the halogen lamp HL is a continuously lit lamp that continuously emits light for at least 1 second or longer. Further, since the halogen lamp HL is a rod-shaped lamp, it has a long life, and by arranging the halogen lamp HL along the horizontal direction, the radiation efficiency to the upper semiconductor wafer W becomes excellent.

Further, a reflector 43 is also provided under the two-stage halogen lamp HL in the housing 41 of the halogen lamp house 4 (FIG. 3). The reflector 43 reflects the light emitted from the plurality of halogen lamps HL toward the heat treatment space 65.

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

Further, the control unit 3 controls the various operation mechanisms provided in the heat treatment apparatus 100. FIG. 10 is a functional block diagram of the control unit 3 of the heat treatment apparatus 100. The configuration of the control unit 3 as hardware is the same as that of a general computer. That is, the control unit 3 includes a CPU, which is a circuit that performs various arithmetic processes, a ROM, which is a read-only memory for storing basic programs, a RAM, which is a read / write memory for storing various information, and control software and data. It has a magnetic disk to store. When the CPU of the control unit 3 executes a predetermined processing program, the processing in the heat treatment apparatus 100 proceeds. Although the control unit 3 is shown in the indexer unit 101 in FIG. 1, the control unit 3 is not limited to this, and the control unit 3 can be arranged at an arbitrary position in the heat treatment apparatus 100.

Further, the reflectance measuring units 135 and 145 provided in the first cool chamber 131 and the second cool chamber 141 are electrically connected to the control unit 3, and the semiconductor wafer measured by the reflectance measuring units 135 and 145. The reflectance on the surface of W is transmitted to the control unit 3. The control unit 3 includes a determination unit 31 and a warning issuing unit 32. The determination unit 31 and the warning issuing unit 32 are functional processing units realized by the CPU of the control unit 3 executing a predetermined processing program. The processing contents of the determination unit 31 and the warning issuing unit 32 will be further described later.

An input unit 33 and a display unit 34 are connected to the control unit 3. The input unit 33 is a device for the operator of the heat treatment apparatus 100 to input various commands and parameters to the control unit 3. The control unit 3 displays various information on the display unit 34. The operator can also set the conditions of the processing recipe that describes the processing procedure and the processing conditions of the semiconductor wafer W from the input unit 33 while checking the display contents of the display unit 34. As the input unit 33 and the display unit 34, a touch panel having both functions can be used, and in the present embodiment, a liquid crystal touch panel provided on the outer wall of the heat treatment apparatus 100 is adopted.

Further, in the present embodiment, the control unit 3 of the heat treatment apparatus 100 is connected to a higher-level host computer 90 via a LAN line or the like. The host computer 90 also has the same hardware configuration as a general computer. The reflectance of the surface of the semiconductor wafer W measured by the reflectance measuring units 135 and 145 is further transmitted from the control unit 3 to the host computer 90 and stored in the storage unit 91 of the host computer 90. The control unit 3 of the plurality of heat treatment devices 100 may be connected to the host computer 90, and the reflectance of the semiconductor wafer W measured by the plurality of heat treatment devices 100 may be stored in the storage unit 91. ..

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 to which impurities (ions) have been added by an ion implantation method. The activation of the impurities is carried out by a 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 will be described, the heat treatment of the semiconductor wafer W in the heat treatment unit 160 will be described.

First, a plurality of untreated semiconductor wafers W into which impurities have been injected are placed in the load port 110 of the indexer section 101 in a state of being accommodated in the carrier C. Then, the delivery robot 120 takes out the unprocessed semiconductor wafers W one by one from the carrier C and carries them into the alignment chamber 231 of the alignment unit 230. In the alignment chamber 231, the direction of the semiconductor wafer W is adjusted by rotating the semiconductor wafer W around a vertical axis in a horizontal plane with the center thereof as a rotation center and optically detecting a notch or the like.

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. When the untreated semiconductor wafer W is carried into the first cool chamber 131, the reflectance measuring unit 135 measures the reflectance on the surface of the semiconductor wafer W. On the other hand, when the untreated semiconductor wafer W is carried into the second cool chamber 141, the reflectance measuring unit 145 measures the reflectance on the surface of the semiconductor wafer W. At this time, the reflectance measuring units 135 and 145 measure the reflectance of the semiconductor wafer W before the heat treatment. The reflectance of the semiconductor wafer W measured by the reflectance measuring units 135 and 145 is transmitted from the control unit 3 to the host computer 90 and stored in the storage unit 91 as the preheating reflectance.

The semiconductor wafer W carried into the first cool chamber 131 or the second cool chamber 141 is carried out to the transfer chamber 170 by the transfer robot 150. When the semiconductor wafer W before heat treatment is transferred from the indexer portion 101 to the transfer chamber 170 via 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. It functions as a path for passing W.

The transfer robot 150 from which the semiconductor wafer W is taken out rotates so as to face the heat treatment unit 160. Subsequently, the gate valve 185 opens 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, if the preceding heat-treated semiconductor wafer W is present in the processing chamber 6, the heat-treated semiconductor wafer W is taken out by one of the transfer hands 151a and 151b, and then the untreated semiconductor wafer W is taken out. W is carried into the processing chamber 6 to replace the wafer. After that, the gate valve 185 closes 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 the flash heat treatment is performed by irradiating the flash light from the flash lamp FL. This flash heat treatment activates the impurities injected into the semiconductor wafer W.

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 carries out the semiconductor wafer W after the flash heat treatment from the processing chamber 6 to the transfer chamber 170. .. The transfer robot 150 from which the semiconductor wafer W has been taken out rotates so as to face the first cool chamber 131 or the second cool chamber 141 from the processing chamber 6. Further, the gate valve 185 closes between the processing chamber 6 and the transfer chamber 170.

After that, the transfer robot 150 carries the heat-treated semiconductor wafer W into the first cool chamber 131 of the cooling unit 130 or the second cool chamber 141 of the cooling unit 140. At this time, if the semiconductor wafer W has passed through the first cool chamber 131 before the heat treatment, it is carried into the first cool chamber 131 even after the heat treatment and passes through the second cool chamber 141 before the heat treatment. If so, it is carried into the second cool chamber 141 even after the heat treatment. In the first cool chamber 131 or the second cool chamber 141, the semiconductor wafer W is cooled after the flash heat treatment. Since the temperature of the entire semiconductor wafer W at the time of being carried out from the processing chamber 6 of the heat treatment unit 160 is relatively high, it is cooled to near room temperature in the first cool chamber 131 or the second cool chamber 141. be.

Further, in parallel with the cooling treatment of the semiconductor wafer W, the reflectance of the semiconductor wafer W after the heat treatment is measured. When the heat-treated semiconductor wafer W is carried into the first cool chamber 131, the reflectance measuring unit 135 measures the reflectance of the surface of the semiconductor wafer W. On the other hand, when the heat-treated semiconductor wafer W is carried into the second cool chamber 141, the reflectance measuring unit 145 measures the reflectance on the surface of the semiconductor wafer W. At this time, the reflectance measuring units 135 and 145 measure the reflectance of the semiconductor wafer W after the heat treatment. The reflectance of the semiconductor wafer W measured by the reflectance measuring units 135 and 145 is transmitted from the control unit 3 to the host computer 90 and stored in the storage unit 91 as the reflectance after heating.

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 carried out from the load port 110 of the indexer unit 101.

The flash heat treatment in the heat treatment unit 160 will be described continuously. Prior to carrying the semiconductor wafer W into the processing chamber 6, the air supply valve 84 is opened, and the exhaust valves 89 and 192 are opened to start air supply / exhaust to the inside of the processing chamber 6. When the valve 84 is opened, nitrogen gas is supplied to the heat treatment space 65 from the gas supply hole 81. Further, when the valve 89 is opened, the gas in the processing chamber 6 is exhausted from the gas exhaust hole 86. As a result, 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 transport opening 66. Further, the atmosphere around the drive unit of the transfer mechanism 10 is also exhausted by the 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 processing step.

Subsequently, the gate valve 185 is opened to open the transfer opening 66, and the semiconductor wafer W to be processed is carried into the heat treatment space 65 in the processing chamber 6 by the transfer robot 150 via the transfer opening 66. The transfer robot 150 advances the transfer hand 151a (or transfer hand 151b) for holding the unprocessed semiconductor wafer W to a position directly above the holding unit 7 and stops the transfer robot 150. Then, the pair of transfer arms 11 of the transfer mechanism 10 move horizontally from the retracted position to the transfer operation position and rise, so that the lift pin 12 protrudes from the upper surface of the holding plate 75 of the susceptor 74 through the through hole 79. And receive the semiconductor wafer W. At this time, the lift pin 12 rises above the upper end of the substrate support pin 77.

After the unprocessed semiconductor wafer W is placed on the lift pin 12, the transfer robot 150 ejects the transfer hand 151a from the heat treatment space 65, and the transfer opening 66 is closed by the gate valve 185. Then, as the pair of transfer arms 11 descend, the semiconductor wafer W is transferred from the transfer mechanism 10 to the susceptor 74 of the holding portion 7 and held in a horizontal posture 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. Further, the semiconductor wafer W is held in the holding portion 7 with the surface on which the pattern is formed and the impurities are injected as the upper surface. A predetermined distance is formed between the back surface of the semiconductor wafer W supported by the plurality of substrate support pins 77 (the main surface opposite to the front surface) and the holding surface 75a of the holding plate 75. The pair of transfer arms 11 descending to the lower part of the susceptor 74 are retracted to the retracted position, that is, inside the recess 62 by the horizontal moving mechanism 13.

After the semiconductor wafer W is held from below in a horizontal position by the susceptor 74 of the holding portion 7, the 40 halogen lamps HL are turned on all at once to start preheating (assist heating). The halogen light emitted from the halogen lamp HL passes through the lower chamber window 64 and the susceptor 74 made of quartz and is irradiated from the lower surface of the semiconductor wafer W. By receiving the light irradiation from the halogen lamp HL, the semiconductor wafer W is preheated and the temperature rises. Since the transfer arm 11 of the transfer mechanism 10 is retracted inside the recess 62, it does not interfere with heating by the halogen lamp HL.

When preheating with 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 wafer temperature 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, which is raised by the light irradiation from the halogen lamp HL, has reached a predetermined preheating temperature T1. That is, 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 based on the measured value by the radiation thermometer 20. The preheating temperature T1 is set to about 600 ° C. to 800 ° C. (700 ° C. in the present embodiment) where impurities added to the semiconductor wafer W are not likely to diffuse due to 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 is maintained at T1.

By performing preheating with such a 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 dissipate heat, tends to be lower than that of the central portion. The region facing the peripheral portion is higher than the region facing the central portion of the semiconductor wafer W. Therefore, the amount of light irradiated to the peripheral portion of the semiconductor wafer W where heat dissipation is likely to occur increases, and the in-plane temperature distribution of the semiconductor wafer W in the preheating step can be made uniform.

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

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

After the flash heat treatment is completed, the halogen lamp HL is turned off after a predetermined time has elapsed. As a result, the semiconductor wafer W rapidly drops from the preheating temperature T1. The temperature of the semiconductor wafer W during the temperature decrease is measured by the radiation thermometer 20, and the measurement result is transmitted to the control unit 3. The control unit 3 monitors whether or not 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 level 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 rise, so that the lift pin 12 is a susceptor. The semiconductor wafer W that protrudes from the upper surface of the 74 and has been heat-treated is received 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 pin 12 is carried out by the transfer hand 151b (or transfer hand 151a) of the transfer robot 150. NS. The transfer robot 150 advances the transfer hand 151b to a position directly below the semiconductor wafer W pushed up by the lift pin 12 and stops it. Then, as the pair of transfer arms 11 descend, the semiconductor wafer W after flash heating is passed to the transfer hand 151b and mounted. After that, the transfer robot 150 ejects the transfer hand 151b from the processing chamber 6 to carry out the processed semiconductor wafer W.

In the present embodiment, the first cool chamber 131 and the second cool chamber 141 are provided with reflectance measuring units 135 and 145 for measuring the reflectance of the surface of the semiconductor wafer W. As described above, the semiconductor wafer W before the heat treatment is always conveyed from the indexer unit 101 to the processing chamber 6 through the first cool chamber 131 or the second cool chamber 141. Further, the semiconductor wafer W after the heat treatment is always returned from the processing chamber 6 to the indexer unit 101 through the first cool chamber 131 or the second cool chamber 141. That is, the first cool chamber 131 and the second cool chamber 141 are installed in the transport path of the semiconductor wafer W connecting the indexer section 101 and the processing chamber 6, and the reflectance measuring sections 135 and 145 are placed on the transport path. It is provided. More precisely, the reflectance measuring units 135 and 145 refer to the outbound route of the semiconductor wafer W transport path from the indexer section 101 to the processing chamber 6 and the transport path of the semiconductor wafer W from the processing chamber 6 to the indexer section 101. It can be considered to be provided on both sides of the return trip.

Therefore, the reflectance measuring units 135 and 145 can measure the reflectance of the semiconductor wafer W before the heat treatment before being carried into the processing chamber 6, and after being carried out from the processing chamber 6 and after the heat treatment. It is also possible to measure the reflectance of the semiconductor wafer W. Then, the reflectance measuring units 135 and 145 measure the reflectance of the semiconductor wafer W before the heat treatment by the flash light irradiation and transmit it to the control unit 3. The reflectance of the semiconductor wafer W before the heat treatment is transmitted from the control unit 3 to the host computer 90 and stored in the storage unit 91 as the preheating reflectance (FIG. 10). Further, the reflectance measuring units 135 and 145 measure the reflectance of the semiconductor wafer W after heat treatment by flash light irradiation and transmit it to the control unit 3. The reflectance of the semiconductor wafer W after the heat treatment is transmitted from the control unit 3 to the host computer 90 and stored in the storage unit 91 as the reflectance after heating.

The reflectance of the semiconductor wafer W after the heat treatment is generally within a certain range depending on the type of the film formed on the semiconductor wafer W and the treatment content. For example, in the case of a process of forming nickel silicide by irradiating a silicon semiconductor wafer W on which a nickel (Ni) thin film is formed with flash light and heating it, heating is performed if the process is normally performed. The reflectance of the processed semiconductor wafer W becomes a substantially constant value. Therefore, it is possible to confirm whether or not the heat treatment of the semiconductor wafer W has been normally performed based on the reflectance of the semiconductor wafer W after the heat treatment. Specifically, the determination unit 31 of the control unit 3 determines whether or not the reflectance of the semiconductor wafer W after the heat treatment is within a preset range according to the type of the semiconductor wafer W and the processing content. do. When the reflectance of the semiconductor wafer W after the heat treatment is within the range, the determination unit 31 determines that the heat treatment of the semiconductor wafer W has been normally performed. On the other hand, when the reflectance of the semiconductor wafer W after the heat treatment is out of the range, the determination unit 31 determines that the heat treatment of the semiconductor wafer W is not normally performed.

In this way, the determination unit 31 determines whether or not the heat treatment of the semiconductor wafer W has been normally performed based on the reflectance of the semiconductor wafer W after the heat treatment. Then, when the determination unit 31 determines that the heat treatment of the semiconductor wafer W is not normally performed, the warning issuing unit 32 issues a warning to the display unit 34 that a processing abnormality has occurred. By doing so, it is possible to easily confirm whether or not the semiconductor wafer W has been normally heat-treated only by measuring the reflectance of the semiconductor wafer W after being heated by the flash light irradiation.

Further, typically, it is preferable to adjust the light emission intensity of the flash lamp FL at the time of flash light irradiation according to the reflectance of the surface of the semiconductor wafer W. If the reflectance of the semiconductor wafer W is low (that is, if the absorptivity is high), it is sufficient that the emission intensity of the flash lamp FL is small in order to raise the surface of the semiconductor wafer W to a predetermined temperature during flash light irradiation. On the contrary, if the reflectance of the semiconductor wafer W is high (that is, if the reflectance is low), it is necessary to increase the emission intensity of the flash lamp FL. When this is executed, the emission intensity of the flash lamp FL (specifically, the voltage applied to the flash lamp FL) based on the reflectance of the semiconductor wafer W before the heat treatment measured by the reflectance measuring units 135 and 145. ) Can be adjusted.

However, in the processing chamber 6, the semiconductor wafer W is preheated by the halogen lamp HL before the flash light is irradiated from the flash lamp FL. It was found that the reflectance of the surface of the semiconductor wafer W changes during preheating depending on the content of the heat treatment. For example, when the semiconductor wafer W whose surface is an amorphous layer is irradiated with light from a halogen lamp HL and preheated by ion implantation, the amorphous layer crystallizes and the reflectance of the semiconductor wafer W changes. When the reflectance of the semiconductor wafer W changes in the preheating stage, even if the reflectance of the semiconductor wafer W before the heat treatment before being carried into the processing chamber 6 is measured, it is based only on the reflectance before the heating. If the light emission intensity of the flash lamp FL is adjusted, the flash lamp FL will emit light with an incorrect light emission intensity. As a result, the surface of the semiconductor wafer W cannot be heated to an appropriate target temperature during flash light irradiation.

Therefore, in the present embodiment, the flash lamp FL is based on both the reflectance of the semiconductor wafer W before the heat treatment (reflectance before heating) and the reflectance of the semiconductor wafer W after the heat treatment (reflectance after heating). I try to determine the emission intensity. This work may be performed, for example, when setting the heating conditions before processing the lot. The lot is a set of semiconductor wafers W to be processed under the same conditions and with the same contents.

Specifically, the pre-heating reflectance and the post-heating reflectance are weighted according to the degree to which the reflectance of the semiconductor wafer W changes in the preheating stage to obtain the reflectance for determining the emission intensity (for example, weighted). Calculate the average). For example, when the semiconductor wafer W whose surface is an amorphous layer is heat-treated by ion implantation, the reflectance of the semiconductor wafer W changes significantly in the preheating step as described above. In such a case, since the reflectance of the semiconductor wafer W at the time when the flash lamp FL emits light is close to the reflectance after heating, the reflectance after heating is weighted to obtain the reflectance for determining the emission intensity. .. On the other hand, for example, when heat treatment is performed on a semiconductor wafer W having a thin film of nickel formed on its surface, the reflectance of the semiconductor wafer W does not change significantly in the preheating stage, and nickel silicide is generated during flash light irradiation. It is formed and the reflectance changes. In such a case, since the reflectance of the semiconductor wafer W at the time when the flash lamp FL emits light is close to the preheating reflectance, the preheating reflectance is weighted to obtain the reflectance for determining the emission intensity. ..

In this way, if the emission intensity of the flash lamp FL is adjusted based on the reflectance after heating in addition to the reflectance before heating, even if the reflectance on the surface of the semiconductor wafer W changes during preheating or irradiation with flash light. The emission intensity of the flash lamp FL can be determined to an appropriate value. As a result, the surface of the semiconductor wafer W can be heated to a desired target temperature during flash light irradiation.

The accuracy of adjusting the emission intensity of such a flash lamp FL increases as the number of data of the underlying pre-heating reflectance and post-heating reflectance increases. Therefore, in the present embodiment, the pre-heating reflectance and the post-heating reflectance of the plurality of semiconductor wafers W processed in the past are stored in the storage unit 91. Further, when a plurality of heat treatment devices 100 are connected to the host computer 90, the pre-heating reflectance and the post-heating reflectance obtained by the plurality of heat treatment devices 100 can be stored in the storage unit 91. , It becomes possible to adjust the light emission intensity of the flash lamp FL with higher accuracy.

However, as the number of data stored in the storage unit 91 increases, it becomes difficult to manually obtain the reflectance and adjust the light emission intensity of the flash lamp FL. Therefore, an artificial intelligence (AI) function is implemented in the host computer 90, and a large amount of preheating reflectance and postheating reflectance data stored in the storage unit 91 are analyzed using the artificial intelligence to obtain an appropriate reflectance. It is preferable to obtain and adjust the emission intensity of the flash lamp FL.

Although the embodiments of the present invention have been described above, the present invention can be modified in various ways other than those described above as long as it does not deviate from the gist thereof. For example, in the above embodiment, the reflectance measuring units 135 and 145 are provided in the first cool chamber 131 and the second cool chamber 141, but the present invention is not limited to this, and any of the transport paths of the semiconductor wafer W is provided. A reflectance measuring unit may be provided. For example, the reflectance measuring unit may be provided in the transfer chamber 170, or may be provided in the indexer unit 101. Alternatively, the reflectance measuring unit may be provided in the alignment chamber 231. When the reflectance measuring unit is provided in the alignment chamber 231, the semiconductor wafer W after the heat treatment is conveyed to the alignment chamber 231 to measure the reflectance after heating. Further, the heat treatment apparatus 100 may be provided with a dedicated reflectance measuring chamber for measuring the reflectance. In this case, the semiconductor wafer W before the heat treatment and the semiconductor wafer W after the heat treatment are conveyed to the reflectance measurement chamber, respectively, and the pre-heating reflectance and the post-heating reflectance are measured. In short, the reflectance of the semiconductor wafer W before heat treatment can be measured before being carried into the processing chamber 6, and the reflectance of the semiconductor wafer W after heat treatment after being carried out from the processing chamber 6 can be measured. It suffices if the reflectance measuring unit is provided as described above.

Further, it may be determined whether or not the heat treatment of the semiconductor wafer W is normally performed based on both the preheating reflectance and the postheating reflectance. In this case, if the difference between the pre-heating reflectance and the post-heating reflectance is within a predetermined range, the determination unit 31 determines that the heat treatment of the semiconductor wafer W has been performed normally, and the determination unit 31 deviates from the range. If so, it is determined that the heat treatment of the semiconductor wafer W is not normally performed.

In addition, when adjusting the emission intensity of the flash lamp FL, in addition to the pre-heating reflectance and post-heating reflectance, various temperatures measured by a radiation thermometer and the light intensity measured by a photometer are taken into consideration. Is also good. By doing so, the emission intensity of the flash lamp FL can be adjusted with higher accuracy.

Further, in the above embodiment, the flash lamp house 5 is provided with 30 flash lamp FLs, but the present invention is not limited to this, and the number of flash lamp FLs 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 may be any number.

Further, in the above embodiment, the semiconductor wafer W is preheated by using a filament type halogen lamp HL as a continuous lighting lamp that continuously emits light for 1 second or longer, but the present invention is not limited to this. Instead of the halogen lamp HL, a discharge type arc lamp (for example, a xenon arc lamp) may be used as a continuous lighting lamp to perform preheating.

Further, the substrate to be processed by the heat treatment apparatus 100 is not limited to the semiconductor wafer, and may be a glass substrate used for a flat panel display such as a liquid crystal display device or a substrate for a solar cell.

3 Control unit 4 Halogen lamp house 5 Flash lamp house 6 Processing chamber 7 Holding unit 10 Transfer mechanism 31 Judgment unit 32 Warning alarm unit 65 Heat treatment space 90 Host computer 91 Storage unit 100 Heat treatment device 101 Indexer unit 130, 140 Cooling unit 131 1st cool chamber 141 2nd cool chamber 135,145 Reflectivity measuring unit 150 Transfer robot 160 Heat treatment unit 230 Alignment unit FL Flash lamp HL Halogen lamp W Semiconductor wafer

Claims (7)

A heat treatment device that heats a substrate by irradiating the substrate with flash light.
A processing chamber that houses the substrate and
A flash lamp that irradiates and heats the substrate housed in the processing chamber with flash light, and
A reflectance measuring unit for measuring the reflectance of the substrate after being heated by flash light irradiation from the flash lamp, and a reflectance measuring unit.
An indexer unit that carries the unprocessed board into the device and carries the treated board out of the device.
Equipped with
The reflectance measuring unit is a heat treatment apparatus provided in a transport path of a substrate from the processing chamber to the indexer unit. In the heat treatment apparatus according to claim 1,
The reflectance measuring unit is a heat treatment apparatus characterized in that it also measures the reflectance of the substrate before irradiating the flash light from the flash lamp. In the heat treatment apparatus according to claim 1 or 2.
A cooling chamber for cooling the heated substrate is installed in the transport path.
The reflectance measuring unit is a heat treatment apparatus provided in the cooling chamber. In the heat treatment apparatus according to any one of claims 1 to 3.
A determination unit that determines whether or not the heat treatment of the substrate has been normally performed based on the reflectance of the substrate measured by the reflectance measuring unit.
A warning issuing unit that issues a warning when the determination unit determines that the heat treatment of the substrate is not normally performed.
A heat treatment apparatus characterized by further comprising. In the heat treatment apparatus according to any one of claims 1 to 4.
A heat treatment apparatus further comprising a storage unit for storing the reflectance of the substrate measured by the reflectance measuring unit. In the heat treatment apparatus according to claim 5,
A heat treatment apparatus characterized in that the light emission intensity of the flash lamp is adjusted by artificial intelligence based on the reflectances of a plurality of substrates stored in the storage unit. In the heat treatment apparatus according to any one of claims 1 to 6.
A heat treatment apparatus further comprising a continuous lighting lamp that irradiates the substrate with light to perform preheating before irradiating the flash light from the flash lamp.

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