JP2014179550A - Substrate processing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate processing apparatus which suppresses deterioration of the inner surface of a treatment gas supply nozzle and have a gas supply nozzle endurable in stable use for a long period of time.SOLUTION: A substrate processing apparatus includes: a substrate holder 30 which holds a plurality of substrates 14 by laminating them in the vertical direction; a processing chamber 45 in which the substrate holder 30 is carried to process substrates 14; and a gas supply nozzle having gas supply holes through which treatment gas is supplied into the processing chamber 45. In the gas supply nozzle, on the nozzle inner surface, a protective film 84 is coated which is formed by Tac or thermal decomposition carbon.

Description

  The present invention relates to a substrate processing apparatus for forming an epitaxial silicon carbide film on a silicon carbide wafer, and more particularly to a technique for suppressing deterioration of a processing gas supply nozzle provided in a heat treatment furnace.

  Silicon carbide (SiC) has attracted attention as an element material for power devices because it has a larger energy band gap and higher withstand voltage than silicon (Si). It is known that SiC has a higher melting point than Si, does not have a liquid phase under normal pressure, and has a small impurity diffusion coefficient, making it difficult to produce substrates and devices as compared to Si.

  For example, a SiC epitaxial film forming apparatus, which is a substrate processing apparatus, has a Si epitaxial film forming temperature of 900 to 1200 ° C., whereas that of SiC is as high as about 1500 to 1800 ° C. Technical measures are necessary to suppress decomposition. In addition, since the film formation proceeds by the reaction of two elements of Si and C, it is necessary to devise a device that is not available in a silicon-based film formation apparatus for ensuring the film thickness and composition uniformity and for controlling the doping level (Patent Literature). 1).

  The gas supply unit in the SiC epitaxial film forming apparatus is usually made of a material that can withstand a high temperature of 1500 ° C. or higher and that takes into consideration the contamination of the substrate with other substances. However, since the gas supply unit using such a material also gradually proceeds in high-temperature hydrogen at 1500 ° C. or higher, the inner surface of the gas supply unit deteriorates over a long period of time, and fine particles are generated little by little. To do. The generated fine particles are carried on the substrate along the gas flow, causing crystal defects and changes in the C concentration of the raw material, resulting in a problem that the film forming conditions change. In addition, the gas supply unit in which the fine particles are generated has to be replaced because it is difficult to clean, resulting in a decrease in productivity.

JP 2012-175072 A

  An object of the present invention is to provide a substrate processing apparatus including a gas supply unit that suppresses deterioration of a process gas supply unit and can withstand long-term stable use.

  According to one aspect of the present invention, a substrate holder that stacks and holds a plurality of substrates in a vertical direction, a processing chamber that carries the substrate holder and processes the substrate, and a processing gas into the processing chamber And a gas supply nozzle having a gas supply hole for supplying the substrate, wherein the gas supply nozzle has a nozzle inner surface coated with a protective film formed of TaC or pyrolytic carbon.

  According to another aspect of the present invention, it is possible to provide a substrate processing apparatus including a gas supply nozzle that suppresses deterioration of the inner surface of the process gas supply nozzle and can withstand long-term stable use.

It is a perspective view of the vertical processing apparatus in the embodiment of the present invention. It is a longitudinal cross-sectional view of the vertical processing apparatus in embodiment of this invention. It is a block diagram of the control part of the vertical processing apparatus in embodiment of this invention. It is the schematic of the process furnace and its peripheral structure in embodiment of this invention. It is explanatory drawing of the coating method of the gas supply nozzle in embodiment of this invention. It is a cross-sectional view of the processing furnace in the embodiment of the present invention.

  First, a general SiC epitaxial apparatus will be described below.

  As a mass-produced SiC epitaxial growth apparatus, apparatuses of a form called a pancake type or a planetary type are mainly used. In a planetary SiC epitaxial growth apparatus, a SiC wafer is held by a wafer holder and supported by a susceptor so as to be suspended. The material gas rises from below through the supply gas path, passes through the lower surface of the SiC wafer, and is exhausted from the side surface of the reaction vessel. The SiC wafer is heated by the induction coil while rotating around the rotation axis and revolving around the rotation axis.

  As described above, in a general SiC epitaxial growth apparatus, several to dozen or more SiC substrates are arranged in a plane on a susceptor heated to a film forming temperature by high frequency or the like, and a source gas or a carrier gas is supplied. A film is being formed. The surface of the susceptor that holds the substrate is directed downward in order to suppress the deposition of deposits due to the source gas on the surface facing the susceptor and the destabilization of SiC epitaxial growth due to the generation of source gas convection. Is arranged.

In a general apparatus, a raw material such as C ₃ H ₈ (propane) or C ₂ H ₄ (ethylene) is used as a carbon raw material, and SiH ₄ (monosilane) or tetrachlorosilane (SiCl ₄ , silicon tetrachloride) is used as a Si raw material. There is also.

  These general SiC epitaxial film forming apparatuses have the following problems. For example, in the reaction space structure, a silicon film forming material gas and a carbon film forming material are supplied from a gas supply unit installed in the center and exhausted from a peripheral part to a wafer arranged in a plane. Generally, the gas concentration distribution changes greatly from the gas supply hole to the exhaust port.

  In general, it is also possible to avoid the film thickness non-uniformity caused by this by rotating the wafer and the susceptor at the time of film formation. However, two or more sheets from the gas supply direction to the gas exhaust port direction (radial direction). If they are arranged, a difference in film thickness occurs between the processed wafers due to the above-mentioned gas concentration difference problem, so that there is a problem that the number of practical wafers that can be processed at one time is limited.

  Further, in order to increase the number of substrates that can be processed at a time, the diameter of the susceptor may be increased. However, increasing the diameter of the susceptor increases the size of the apparatus and increases the cost. This problem becomes more serious as the wafer diameter increases.

  On the other hand, since the substrate processing apparatus used in the silicon film forming apparatus can process a plurality of, for example, 25 to 100 wafers in a vertical direction at once with a footprint equivalent to one wafer, Very advantageous for mass production. Therefore, the inventors of the present application examined applying a vertical film forming apparatus to SiC film formation.

  As a problem when this vertical film forming apparatus is applied to SiC film formation, there is a material of the reaction space constituting member. Since the Si film-forming apparatus is mainly processed at 1200 ° C. or lower, high purity and stable quartz glass or the like is mainly used as a reaction space material. However, since SiC epitaxial growth is processed at a high temperature of 1500 ° C. or higher, conventional quartz glass has a problem in heat-resistant temperature and cannot be used.

  In addition, in the vertical SiC epitaxial film forming apparatus, a method of separately supplying Si source gas and C source gas is employed to suppress nozzle clogging due to SiC film formation in the nozzle. Since it is decomposed (reduced) by hydrogen in the nozzle, an inert gas such as Ar is introduced into the nozzle as a carrier gas in order to suppress decomposition. Further, an etching gas such as HCl is added so that Si does not precipitate in the nozzle even if it is decomposed in the nozzle.

Propane or ethylene is used as the C raw material, and hydrogen gas is introduced into the furnace as a carrier gas. Propane and ethylene are present in the form of C ₂ H ₂ even if they are decomposed in the nozzle, and the raw material C is not deposited and deposited as in the case of Si raw material. Since the etching progresses gradually, the inner surface of the nozzle deteriorates and fine particles are generated little by little, causing crystal defects and changing the C concentration of the raw material, thereby changing the film formation conditions, It has been found that a technical problem peculiar to the vertical SiC epitaxial growth apparatus has arisen that it is necessary to replace the nozzle and the productivity is lowered.

  The present invention is based on the above findings found by the present inventors.

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

  FIG. 1 shows an example of a semiconductor manufacturing apparatus 10 as a substrate processing apparatus for forming a SiC epitaxial film in an embodiment of the present invention. This semiconductor manufacturing apparatus 10 is a batch type vertical processing apparatus, and has a housing 12 in which main parts are arranged. In the semiconductor manufacturing apparatus 10, a hoop (also referred to as a FOUP, hereinafter referred to as a pod) 16 is used as a wafer carrier as a substrate container that stores a wafer 14 as a substrate made of, for example, Si or SiC. A pod stage 18 is disposed on the front side of the housing 12, and the pod 16 is transported to the pod stage 18 from the outside of the semiconductor manufacturing apparatus 10. For example, 25 wafers 14 are stored in the pod 16 and set on the pod stage 18 with the lid closed.

  A pod transfer device 20 is arranged on the front side in the housing 12 and at a position facing the pod stage 18. A pod storage shelf 22, a pod opener 24, and a substrate number detector 26 are disposed in the vicinity of the pod transfer device 20. The pod storage shelf 22 is disposed above the pod opener 24 and configured to hold a plurality of pods 16 mounted thereon. The substrate number detector 26 is disposed adjacent to the pod opener 24. The pod carrying device 20 carries the pod 16 among the pod stage 18, the pod storage shelf 22, and the pod opener 24. The pod opener 24 opens the lid of the pod 16, and the substrate number detector 26 detects the number of wafers 14 in the pod 16 with the lid opened.

  A substrate transfer device 28 and a boat 30 as a substrate holder are disposed in the housing 12. The substrate transfer machine 28 has an arm (tweezer) 32 and has a structure that can be moved up and down, advanced and retracted, and rotated by a driving means (not shown). The arm 32 can take out, for example, five wafers. By moving the arm 32, the wafer 14 is transferred between the pod 16 and the boat 30 placed at the position of the pod opener 24.

  As shown in FIG. 2, the boat 30 is made of a heat-resistant material such as carbon graphite or SiC, for example, and a plurality of wafers 14 are aligned in a horizontal posture and aligned with each other in the vertical direction. It is configured to hold in a state of being laminated at a predetermined interval. Each wafer 14 is held in a state in which the lower surface is exposed to a wafer holder 15 including an annular lower holder 15a and a disk-shaped upper holder 15b. A boat heat insulating part 34 as a cylindrical heat insulating member made of a heat resistant material such as SiC is disposed at the lower part of the boat 30. It is configured to be difficult to be transmitted to the side (see FIG. 2). A processing furnace 40 is disposed in the upper part on the back side in the housing 12. The boat 30 loaded with a plurality of wafers 14 is loaded into the processing furnace 40 and subjected to heat treatment.

  In the illustrated example, the manifold 91 is provided with at least one longitudinal first gas supply nozzle 60 having at least one first gas supply hole 68 in the longitudinal direction in the illustrated example. At least one second gas supply nozzle 70 having at least one second gas supply hole 72 and a gas exhaust port 90 for exhausting the gas in the reaction tube 42 to the outside are provided. . The gas exhaust port 90 is not limited to gas exhaust in the reaction tube space, and may be configured to include an exhaust port for exhausting an inert gas supplied between the reaction tube 42 and a heat insulating material 54 described later. Good. The first gas supply hole 68 supplies at least a carbon-containing gas and a reducing gas. The second gas supply hole 72 supplies at least silicon-containing gas and chlorine-containing gas, or silicon atoms, chlorine atom-containing gas, and chlorine-containing gas.

  The processing furnace 40 includes a reaction tube 42 that forms a cylindrical reaction space. The reaction tube 42 is made of a heat-resistant material such as quartz or SiC, and is formed in a cylindrical shape with the upper end closed and the lower end opened. A reaction space 45 is formed in the hollow cylindrical portion inside the reaction tube 42. The reaction space 45 stores wafers 14 made of Si, SiC, or the like in a state in which the wafers 30 are aligned in a horizontal posture and aligned with each other and stacked and held at predetermined intervals in the vertical direction. It is configured to be possible.

  Below the reaction tube 42, a manifold 91 is disposed concentrically with the reaction tube 42. The manifold 91 is made of, for example, stainless steel and is formed in a cylindrical shape with an upper end and a lower end opened. The manifold 91 is provided so as to support the reaction tube 42. An O-ring (not shown) is provided between the manifold 91 and the reaction tube 42 as a seal member. The manifold 91 is supported by a holding body (not shown), so that the reaction tube 42 is installed vertically. A reaction vessel is formed by the reaction tube 42 and the manifold 91.

  The processing furnace 40 includes a heated object 48 to be heated and an induction coil (or also called a magnetic coil) 50 as a magnetic field generation unit. The heated object 48 is disposed in the reaction space 45. The heated body 48 is heated by a magnetic field generated by an induction coil 50 provided outside the reaction tube 42. The induction coil 50 is provided so as to wind around the reaction tube 42. When the heated object 48 generates heat, the reaction space 45 is heated. The heated object 48 is easily cylindrically heated by an induction current generated by the induction coil 50 and is made of a material having excellent heat resistance, such as carbon graphite, with a closed upper end and an open lower end. Is formed.

  In the vicinity of the object to be heated 48, a temperature sensor (not shown) is provided as a temperature detector for detecting the temperature in the reaction space 45. A temperature control unit 52 is electrically connected to the induction coil 50 and the temperature sensor. By adjusting the amount of current supplied to the induction coil 50 based on the temperature information detected by the temperature sensor, the reaction space 45 is filled. It is configured to control to have a predetermined temperature distribution at a predetermined timing (see FIG. 3).

  Inside the heated body 48, a first gas supply nozzle 60 and a second gas supply nozzle 70 are provided to form a reaction space (processing chamber) 45 to which a reaction gas is supplied. A heat insulating material 54 is provided between the heated object 48 and the reaction tube 42, and by providing this heat insulating material 54, the heat of the heated object 48 is transmitted to the reaction tube 42 or the outside of the reaction tube 42. Can be suppressed. The heat insulating material 54 is made of, for example, a carbon felt that is not easily induced, and is formed in a cylindrical shape with the upper end closed and the lower end opened.

  In addition, an outer heat insulating wall 92 having, for example, a water cooling structure is provided outside the induction coil 50 so as to suppress the heat in the reaction space 45 from being transmitted to the outside so as to surround the reaction space 45. . The outer heat insulating wall 92 is made of a material that is difficult to be induction-heated by the induction current generated from the induction coil 50, for example, a material such as copper (Cu), and is formed in a cylindrical shape having an open upper end and a lower end. Further, a magnetic shield 58 for preventing the magnetic field generated by the induction coil 50 from leaking outside is provided outside the outer heat insulating wall 92. Preferably, the magnetic shield 58 is made of a material that is difficult to be induction-heated by an induction current generated from the induction coil, for example, a material such as copper (Cu) or aluminum (Al), and has a closed upper end and an open lower end. It is formed into a shape.

  As shown in FIG. 2, the manifold 91 is provided with a first gas supply nozzle 60 and a second gas supply nozzle 70 extending upward between the heated body 48 and the boat 30. . At least one first gas supply nozzle 60 is provided to supply a processing gas to the wafers 14 on the boat 30. In the illustrated example, a plurality of first gas supply holes 68 are provided at predetermined intervals in the vertical direction. Is provided. At least one second gas supply nozzle 70 is provided to supply a processing gas to the wafers 14 on the boat 30. In the illustrated example, a plurality of second gas supply holes 72 are provided at predetermined intervals in the vertical direction. Is provided.

The first gas supply nozzle 60 and the second gas supply nozzle 70 are made of carbon graphite so as to withstand a high temperature of 1500 ° C. or higher, and are attached to the manifold 91 so as to penetrate the manifold 91. The first gas supply nozzle 60 is connected to a first gas supply pipe 222 that is a first gas supply system. In this example, the first gas supply pipe 222 is connected to the propane (C ₃ H ₈ ) gas source 210a via the MFC 211a and the valve 212a, and is also connected to the argon (Ar) gas source via the MFC 211b and the valve 212b. And a hydrogen (H ₂ ) gas source 210b so as to be switchable. The supply flow rate, concentration, and partial pressure of propane (C ₃ H ₈ ) gas and argon (Ar) gas or hydrogen (H ₂ ) gas supplied into the reaction space 45 can be controlled.

The second gas supply nozzle 70 is connected to a second gas supply pipe 240 that is a second gas supply system. In this example, the second gas supply pipe 240 is a tetrachlorosilane (SiCl ₄ ) gas source via a mass flow controller (hereinafter referred to as MFC) 211c and a valve 212c as a flow rate controller (flow rate control means). 210c. The second gas supply pipe 240 is connected to a hydrogen chloride (HCl) gas source 210d through an MFC 211d and a valve 212d. Further, the second gas supply pipe 240 is connected to an argon (Ar) gas source 210e as a carrier gas via an MFC 211e and a valve 212e.

With this configuration, the supply flow rate, concentration, and partial pressure of tetrachlorosilane (SiCl ₄ ) gas, hydrogen chloride (HCl) gas, and argon (Ar) gas supplied into the reaction space 45 can be controlled. The valves 212c, 212d, and 212e, and the MFCs 211c, 211d, and 211e are electrically connected to the gas flow rate control unit 78, and are controlled by the controller 152 so that the flow rate of the supplied gas becomes a predetermined flow rate at a predetermined timing. (See FIG. 3).

A first gas supply nozzle 60 that supplies at least a carbon-containing gas and a reducing gas is provided in the reaction space 45. The second gas supply nozzle 70 is made of carbon graphite so as to withstand a high temperature of 1500 ° C. or higher, and is attached to the manifold 91 so as to penetrate the manifold 91. The first gas supply hole 68 provided in the first gas supply nozzle 60 has, for example, propane (C ₃ H ₈ ) gas as a carbon-containing gas and hydrogen (H ₂ ) gas or argon (Ar) gas as a reducing gas, for example. , Supplied into the reaction space 45.

Incidentally, as the silicon-containing gas, is exemplified tetrachlorosilane (SiCl ₄₎ gas is not limited _{thereto, SiH 4, SiH 2 Cl 2} , SiHCl 3, may be used _Si 2 Cl ₆ gas or the like, also these A combination of gases may be used.

Although exemplified propane _(C 3 _{H 8)} gas as a carbon-containing gas is not limited thereto, ethylene _(C 2 _{H 4)} gas, acetylene _(C 2 _{H 2)} may be used gas or the like, and, These gases may be used in combination.

Although exemplified hydrogen chloride (HCl) gas as a chlorine-containing gas is not limited thereto, chlorine _(Cl 2), chlorine trifluoride (ClF ₃₎ may be used gases such as, also, these gases You may use it in combination.

Further, hydrogen (H ₂ ) gas and argon (Ar) gas are exemplified as the carrier gas, but not limited thereto, helium (He), neon (Ne), krypton (Kr), xenon (Xe) gas, etc. Gas or inert gas may be used. The first gas supply hole 68 and the second gas supply hole 72 are each a plurality of sheets that are arranged in a horizontal position on the boat 30 and aligned in the center and stacked and held at predetermined intervals in the vertical direction. It is preferable to provide such a wafer 14 so that gas is supplied for each of the wafers 14.

  This makes it easy to control the in-plane uniformity of the film thickness of each wafer 14. However, the present invention is not limited to this, and at least one of the first gas supply hole 68 and the second gas supply hole 72 is provided in the arrangement region (substrate arrangement region) of the wafers 14 stacked in the vertical direction. May be. In the above-described embodiment, the carbon-containing gas and the reducing gas are supplied from the first gas supply nozzle 60 and the silicon-containing gas and the chlorine-containing gas are supplied from the second gas supply nozzle 70. A gas supply nozzle may be provided for the supply.

  Here, the reason for constituting the first gas supply system and the second gas supply system described above will be described. A plurality of wafers 14 made of SiC or the like are aligned and held in a horizontal position with their centers aligned, and stacked and held at predetermined intervals in the vertical direction, and a silicon-containing gas, a carbon-containing gas, and a reducing gas. Is supplied from a single long gas supply nozzle extending in the longitudinal direction, the raw material gas is consumed in the gas supply nozzle, and the raw material gas is supplied downstream of the gas supply nozzle. Gas shortage occurs, and deposits such as SiC film deposited by reaction in the gas supply nozzle block the gas supply nozzle, or the material gas supply becomes unstable or particles are generated. Problems are likely to arise.

  Note that a dopant gas further containing impurities may be supplied into the reaction space 45 from the first gas supply hole 68 or the second gas supply hole 72. However, the present invention is not limited to this, and a gas supply nozzle may be further provided to supply the dopant gas to supply the dopant gas into the reaction space 45.

  As shown in FIG. 2, the gas exhaust port 90 is connected to the first gas supply nozzle 60 connected to the first gas supply hole 68 and the second gas supply connected to the second gas supply hole 72. A gas exhaust pipe 230 connected to the gas exhaust port 90 is provided in the manifold 91 so as to be located on the opposite surface with respect to the position of the nozzle 70. A vacuum exhaust device 220 such as a vacuum pump is connected to the downstream side of the gas exhaust pipe 230 through a pressure sensor 93 as a pressure detector and an APC (Auto Pressure Controller, hereinafter referred to as APC) valve 214 as a pressure regulator. Yes. A pressure control unit 98 is electrically connected to the pressure sensor 93 and the APC valve 214, and the pressure control unit 98 adjusts the opening degree of the APC valve 214 based on the pressure detected by the pressure sensor 93. Thus, the pressure in the reaction space 45 is controlled to become a predetermined pressure at a predetermined timing (see FIG. 3).

  In this way, at least a silicon-containing gas and a chlorine-containing gas are supplied from the first gas supply hole 68, and at least a carbon-containing gas and a reducing gas are supplied from the second gas supply hole 72. Since it flows parallel to the surface of the wafer 14 made of silicon or silicon carbide and flows toward the gas exhaust port 90, the entire wafer 14 is efficiently and uniformly exposed to the gas.

In FIG. 2, reference numeral 260 denotes a third gas supply hole for supplying a cleaning gas such as chlorine trifluoride (ClF ₃ ) in order to remove by-products generated in the exhaust pipe. The third gas supply pipe 260 is connected to a gas source 210f of chlorine trifluoride (ClF ₃ ) as a cleaning gas via an MFC 211f and a valve 212f.

  Next, the configuration around the processing furnace 40 will be described. FIG. 4 shows a schematic diagram of the processing furnace 40 and its peripheral structure. Below the processing furnace 40, a seal cap 102 is provided as a furnace port lid for secretly closing the lower end opening of the processing furnace 40. The seal cap 102 is made of, for example, a metal such as stainless steel and has a disk shape. On the upper surface of the seal cap 102, an O-ring is provided as a seal material that comes into contact with the lower end of the processing furnace 40. A rotation mechanism 218 is provided on the seal cap 102.

  The rotating shaft 106 of the rotating mechanism 218 is connected to the boat 30 through the seal cap 102, and is configured to rotate the wafer 14 by rotating the boat 30. The seal cap 102 is configured to be moved up and down in the vertical direction by an elevating motor 122, which will be described later, as an elevating mechanism directed to the outside of the processing furnace 40, whereby the boat 30 is carried into and out of the processing furnace 40. It is possible to do. A drive control unit 108 is electrically connected to the rotation mechanism 218 and the lifting motor 122, and is configured to control to perform a predetermined operation at a predetermined timing (see FIG. 3).

  A lower substrate 112 is provided on the outer surface of the load lock chamber 110 as a spare chamber. The lower substrate 112 is provided with a guide shaft 116 that is fitted to the lifting platform 114 and a ball screw 118 that is screwed to the lifting platform 114. The upper substrate 120 is provided on the upper ends of the guide shaft 116 and the ball screw 118 that are erected on the lower substrate 112. The ball screw 118 is rotated by an elevating motor 122 provided on the upper substrate 120. When the ball screw 118 rotates, the lifting platform 114 is configured to move up and down.

  A hollow elevating shaft 124 is suspended from the elevating table 114, and the connection between the elevating table 114 and the elevating shaft 124 is airtight. The elevating shaft 124 moves up and down together with the elevating table 114. The lifting shaft 124 passes through the top plate 126 of the load lock chamber 110. The through hole of the top plate 126 through which the elevating shaft 124 passes has a sufficient margin so as not to contact the elevating shaft 124.

  Between the load lock chamber 110 and the lifting platform 114, a bellows 128 is provided as a hollow elastic body having elasticity so as to cover the periphery of the lifting shaft 124 in order to keep the load lock chamber 110 airtight. The bellows 128 has a sufficient expansion / contraction amount that can correspond to the amount of elevation of the lifting platform 114, and the inner diameter of the bellows 128 is sufficiently larger than the outer shape of the lifting shaft 124 so that it does not come into contact with the expansion / contraction of the bellows 128. It is configured.

  An elevating board 130 is fixed horizontally to the lower end of the elevating shaft 124. A drive unit cover 132 is airtightly attached to the lower surface of the elevating substrate 130 via a seal member such as an O-ring. The elevating board 130 and the drive unit cover 132 constitute a drive unit storage case 134. With this configuration, the inside of the drive unit storage case 134 is isolated from the atmosphere in the load lock chamber 110. Further, a rotation mechanism 218 of the boat 30 is provided inside the drive unit storage case 134, and the periphery of the rotation mechanism 218 is cooled by the cooling mechanism 136.

  The power cable 138 passes from the upper end of the elevating shaft 124 through the hollow portion of the elevating shaft 124 and is guided and connected to the rotating mechanism 218. A cooling water flow path 140 is formed in the cooling mechanism 136 and the seal cap 102. The cooling water pipe 142 passes from the upper end of the elevating shaft 124 through the hollow portion of the elevating shaft 124 and is led to the cooling water passage 140 and connected thereto.

  As the elevating motor 122 is driven and the ball screw 118 rotates, the drive unit storage case 134 is raised and lowered via the elevating table 114 and the elevating shaft 124. As the drive unit storage case 134 rises, the seal cap 102 provided in an airtight manner on the elevating substrate 130 closes the furnace port 145 that is an opening of the processing furnace 40, thereby enabling wafer processing. When the drive unit storage case 134 is lowered, the boat 30 is lowered together with the seal cap 102, and the wafer 14 can be carried out to the outside.

  FIG. 3 shows a control configuration of each part constituting the semiconductor manufacturing apparatus 10 for forming a SiC epitaxial film. The temperature control unit 52, the gas flow rate control unit 78, the pressure control unit 98, and the drive control unit 108 are electrically connected to a main control unit 150 that controls the entire semiconductor manufacturing apparatus 10. The main control unit 150 includes an operation unit and an input / output unit (not shown). These temperature control unit 52, gas flow rate control unit 78, pressure control unit 98, and drive control unit 108 are configured as a controller 152.

  Next, a method for forming, for example, a SiC film on a substrate such as a wafer 14 made of SiC or the like as one step of a semiconductor device manufacturing process using the semiconductor manufacturing apparatus 10 configured as described above will be described. To do. In the following description, the operation of each part constituting the semiconductor manufacturing apparatus 10 is controlled by the controller 152.

  First, when a pod 16 containing a plurality of wafers 14 is set on the pod stage 18, the pod 16 is transferred from the pod stage 18 to the pod storage shelf 22 by the pod transfer device 20, and the pod storage shelf 22 is stocked. To do. Next, the pod 16 stocked on the pod storage shelf 22 is transported and set to the pod opener 24 by the pod transport device 20, the lid of the pod 16 is opened by the pod opener 24, and the pod 16 is detected by the substrate number detector 26. The number of wafers 14 accommodated in is detected.

  Next, the wafer 14 is taken out from the pod 16 at the position of the pod opener 24 by the substrate transfer device 28 and transferred to the boat 30. When a plurality of wafers 14 are loaded into the boat 30, the boat 30 holding the plurality of wafers 14 is loaded into the reaction space 45 by the lifting / lowering operation of the lifting / lowering table 114 and the lifting / lowering shaft 124 by the lifting / lowering motor 122 (boat loading). ) In this state, the seal cap 102 seals the lower end of the manifold 91 via the O-ring.

  The reaction space 45 is evacuated by the evacuation device 220 so that the pressure in the reaction space 45 becomes a predetermined pressure (degree of vacuum). At this time, the pressure in the reaction space 45 is measured by the pressure sensor 93, and the APC valve 214 communicating with the gas exhaust port 90 is feedback-controlled based on the measured pressure. Further, the object to be heated 48 is heated so that the wafer 14 and the reaction space 45 have a predetermined temperature. At this time, the energization amount to the induction coil 50 is feedback-controlled based on the temperature information detected by the temperature sensor so that the reaction space 45 has a predetermined temperature distribution. Subsequently, the wafer 14 is rotated in the circumferential direction by rotating the boat 30 by the rotation mechanism 218.

Subsequently, the silicon-containing gas and the chlorine-containing gas contributing to the SiC epitaxial growth reaction are respectively supplied from the gas sources 210a, 210b, and 210c, and are ejected into the reaction space 45 from the first gas supply hole 68, and also contain carbon. Hydrogen (H ₂ ) gas, which is a gas and a reducing gas, is supplied from the gas sources 210e and 210d, and is ejected into the reaction space 45 from the second gas supply hole 72 to cause a SiC epitaxial growth reaction.

At this time, the openings of the corresponding MFCs 211a and 211b are adjusted so that the silicon-containing gas and the chlorine-containing gas have predetermined flow rates, and then the valves 212a and 212b are opened, and the respective gases are the first gas. After flowing through the supply pipe 222, it flows through the first gas supply nozzle 60 and is supplied into the reaction space 45 from the first gas supply hole 68. Further, the opening of the corresponding MFC 211c, 211d, 211e is adjusted so that the carbon-containing gas and hydrogen (H ₂ ) gas as the reducing gas have predetermined flow rates, and then the valves 212c, 212d, 1212e are opened. Then, after each gas flows through the second gas supply pipe 240, it flows through the second gas supply nozzle 70 and is introduced into the reaction space 45 through the second gas supply hole 72.

  The gas supplied from the first gas supply hole 68 and the second gas supply hole 72 passes through the reaction space 45 inside the to-be-heated body 48 in the reaction space 45 and passes from the gas exhaust port 90 to the gas exhaust pipe 230. Exhausted through. When the gas supplied from the first gas supply hole 68 and the second gas supply hole 72 passes through the reaction space 45, the gas comes into contact with the wafer 14 made of SiC or the like, and on the surface of the wafer 14. SiC epitaxial film growth is performed.

  Further, after the opening degree of the corresponding MFC 211e is adjusted by the gas supply source 210e so that argon (Ar) gas, which is a rare gas as an inert gas, has a predetermined flow rate, the valve 212e is opened, After flowing through the second gas supply pipe 240, the gas is supplied into the reaction space 45 from the third gas supply hole 260. The argon (Ar) gas supplied from the third gas supply hole 260 passes between the heat insulating material 54 and the reaction tube 42 in the reaction space 45 and is exhausted from the gas exhaust port 90.

  When a preset time elapses, the above gas supply is stopped, and the SiC epitaxial film growth is stopped. Further, an inert gas is supplied into the reaction space 45 from an inert gas supply source (not shown), the reaction space 45 is replaced with the inert gas, and the pressure in the reaction space 45 is returned to normal pressure.

  Thereafter, the seal cap 102 is lowered by the elevating motor 122 so that the lower end of the manifold 91 is opened, and the processed wafer 14 is carried out from the lower end of the manifold 91 to the outside of the reaction tube 42 while being held in the boat 30. (Boat unloading) The boat 30 waits at a predetermined position until all the wafers 14 supported by the boat 30 are cooled. Next, when the wafer 14 of the boat 30 that has been waiting is cooled to a predetermined temperature, the substrate transfer device 28 takes out the wafer 14 from the boat 30 and transfers it to the empty pod 16 set in the pod opener 24. And accommodate. Thereafter, the pod 16 containing the wafer 14 is transferred to the pod storage shelf 22 or the pod stage 18 by the pod transfer device 20. In this way, a series of operations of the semiconductor manufacturing apparatus 10 is completed.

As described above, the growth of the deposited film in the gas supply nozzle is suppressed, and in the reaction space 45, the silicon-containing gas, the carbon-containing gas, the chlorine-containing gas, and hydrogen (H ₂ ) that is the reducing gas supplied from the gas supply nozzle. In a state where a plurality of wafers 14 composed of SiC or the like are aligned in a horizontal posture and aligned in the center and stacked and held at a predetermined interval in the vertical direction by the reaction of the gas. In addition, silicon carbide epitaxial growth can be performed.

  As shown in FIG. 6, a plurality of first gas supply nozzles 60 and second gas supply nozzles 70 are provided along the inner periphery of the heated object 48 in the reaction space 45, and the first gas supply holes 68 are provided. The second gas supply holes 72 may be jetted toward the center of the wafer 14 and the second gas supply nozzles 70 may be disposed at both ends. In addition to the above configuration, the first gas supply nozzle 60 and the second gas supply nozzle 70 may be provided alternately. As a result, the number of locations where the film forming gas supplied from the first gas supply hole 68 and the reducing gas supplied from the second gas supply hole 72 are mixed increases, and the film forming gas is reached before reaching the wafer 14. And the reducing gas can be efficiently mixed, so that the bias of the supply gas is suppressed and the in-plane uniformity of the film thickness is further improved.

  The gas supply nozzle according to the embodiment of the present invention used in the substrate processing apparatus or the substrate processing method as described above will be described in detail as in the following examples.

  In the first embodiment, the first gas supply nozzle 60 and the second gas supply nozzle 70 are fitted into the cylindrical member 80 having both ends opened and the cylindrical member 80 as shown in FIGS. And a lid member 82 that closes one end of the cylindrical member 80. The first gas supply hole 68 and the second gas supply hole 72 are not shown. As one method, a protective film formed by pyrolytic carbon or tantalum carbide (TaC) on the inner surface of the cylindrical member 80 with the lid member 82 attached to one end (upper end) of the cylindrical member 80. 84 to coat evenly.

  In this case, if one end (upper end) of the cylindrical member 80 is closed, uneven coating may occur on the inner surface of the cylindrical member 80. To prevent this uneven coating, FIG. In the state where the lid member 82 is removed from one end of the cylindrical member 80, the protective film 84 is coated on the inner surface of the cylindrical member 80 from the other end (lower end) to one end (upper end) and one end ( It is preferable that the upper end surface is also coated with a protective film 85. Next, the protective film 86 is also coated on the inner surface of the lid member 82 (the region that fits on the inner surface of the tubular member 80). Further, the lid member 82 is fitted and attached to one end (upper end) of the cylindrical member 80, and from the other end (lower end) to the one end (upper end) of the outer surface of the cylindrical member 80 as shown in FIG. It is preferable that the protective film 88 is uniformly coated 88 and the outer surface of the lid member 82 is uniformly coated with the protective film 89.

  As described above, the inner surfaces of the first gas supply nozzle 60 and the second gas supply nozzle 70 are coated with pyrolytic carbon or TaC, thereby being strong against hydrogen etching and suppressing deterioration of the inner surface of the gas supply nozzle. And generation of carbon fine particles can be suppressed. Furthermore, by using this structure, the inside of the furnace can be subjected to hydrogen etching at a higher temperature than during film formation, and at this time, deterioration of the inner surface of the gas supply nozzle can be prevented. However, since TaC coating is weak to chlorine-based gas, it is necessary to avoid mixing of chlorine-based gas. By adopting the gas supply nozzle having such a structure, the generation of carbon fine particles can be suppressed in advance, so that the same gas supply nozzle can be used for a long time without replacement, and productivity can be improved. .

In the film formation process of the SiC epitaxial film, propane (C ₃ H ₈ ) is used as a hydrogen carrier from the first gas supply nozzle 60 connected to the first gas supply pipe 222 which is the first gas supply system. Then, SiC1 ₄ is supplied from a second gas supply pipe 240, which is a second gas supply system, as a silicon raw material using an argon carrier. In addition to these source gases, the first gas supply system suppresses the clogging in the vicinity of the nozzle holes of the first gas supply pipe 222, and the inside of the nozzles of the second gas supply pipe 240, which is the second gas supply system. In order to suppress Si precipitation, a Cl-based gas such as HCl is simultaneously supplied. When film formation is continued in such a gas supply system, the inner surface of the first gas supply nozzle 60 is gradually deteriorated by etching with hydrogen, and carbon fine particles are generated.

Thus, in order to suppress the generation of carbon fine particles, in Example 2, the carrier gas supplied from the first gas supply pipe 222 which is the first gas supply system is changed from hydrogen to argon (Ar) gas. . By supplying propane (C ₃ H ₈ ) with an argon carrier, carbon is deposited by thermal decomposition of propane (C ₃ H ₈ ), that is, a carbon film is formed by CVD. Usually, it is known that the pyrolytic carbon coating is a dense and strong film, and the inner surface of the first gas supply pipe 222 deteriorated by hydrogen etching is covered with a strong carbon film. This makes it possible to suppress the generation of carbon fine particles. At this time, since pyrolytic carbon may have a low film density in the vicinity of 1600 ° C., it is preferable to generate pyrolytic carbon in a temperature range of 1600 ° C. or less, more preferably avoiding the processing temperature range, and more preferably. It is preferable to generate pyrolytic carbon in a temperature range of 1200 ° C to 1400 ° C. By performing such coating periodically, the generation of carbon fine particles can be suppressed in advance, so that the same nozzle can be operated for a long time without replacement, and productivity can be improved.

Further, at least a carbon-containing gas and a reducing gas are supplied from the first gas supply nozzle 60, and at least a silicon-containing gas and a chlorine-containing gas are supplied from the second gas supply nozzle 70, thereby providing a gas supply nozzle. It is possible to suppress the consumption of the supply gas in the interior, suppress the blockage in the gas supply nozzle, and prevent the generation of particles. Preferably, silicon-containing gas, chlorine-containing gas, and rare gas such as argon (Ar) gas is supplied as carrier gas from the first gas supply nozzle 60, and carbon-containing gas is supplied from the second gas supply nozzle 70. For example, hydrogen (H ₂ ) gas as a reducing gas may be supplied.

  The above is only one preferred embodiment of the present invention, and the present invention is not limited to the above embodiment, and various modifications can be made without departing from the scope of the present invention. Furthermore, the present invention can be applied not only to a semiconductor wafer but also to a glass substrate processing apparatus for forming a liquid crystal display element.

  As mentioned above, although this invention has been demonstrated along embodiment, the main aspect of this invention is added here.

[Appendix 1]
A substrate holder for vertically stacking and holding a plurality of substrates;
A processing chamber for carrying in the substrate holder and processing the substrate;
A gas supply nozzle having a gas supply hole for supplying a processing gas into the processing chamber;
The gas supply nozzle includes a cylindrical member having both ends opened, a lid member that is fitted to the cylindrical member and closes one end of the cylindrical member,
A substrate processing apparatus.

[Appendix 2]
The substrate processing apparatus according to appendix 1, wherein the gas supply nozzle is coated on the inner surface of the cylindrical member and the lid member with a predetermined protective film, and the cylindrical member and the lid member are fitted. A substrate processing apparatus which is coated again with a predetermined protective film after combining.

[Appendix 3]
The substrate processing apparatus according to appendix 1 or appendix 2, wherein the gas supply nozzle supplies a carbon-containing gas.

[Appendix 4]
The substrate processing apparatus according to appendix 2 or appendix 3, wherein the protective film is formed of TaC or pyrolytic carbon.

[Appendix 5]
The substrate processing apparatus according to appendix 4, wherein the carrier gas supplied from the gas supply nozzle is switched from H ₂ gas to Ar gas when the protective film is formed.

[Appendix 6]
Carrying a substrate holding tool holding a plurality of substrates into a processing chamber;
A cylindrical member having a gas supply hole for supplying a processing gas into the processing chamber and having both ends opened, and a lid member that is fitted to the cylindrical member and closes one end of the cylindrical member. Supplying the processing gas with a gas supply nozzle;
A substrate processing method comprising:

[Appendix 7]
Carrying a substrate holder holding a plurality of substrates into the processing chamber;
A cylindrical member having a gas supply hole for supplying a processing gas into the processing chamber and having both ends opened, and a lid member that is fitted to one end of the cylindrical member and closes one end of the cylindrical member Supplying the processing gas by the gas supply nozzle,
A method for manufacturing a semiconductor device, comprising:

[Appendix 8]
Carrying a substrate holder holding a plurality of substrates into the processing chamber;
A cylindrical member having a gas supply hole for supplying a processing gas into the processing chamber and having both ends opened, and a lid configured to be fitted to the cylindrical member and close one end of the cylindrical member Supplying the processing gas by a gas supply nozzle constituted by a member;
A substrate manufacturing method comprising:

[Appendix 9]
A substrate holder for vertically stacking and holding a plurality of substrates;
A processing chamber for carrying in the substrate holder and processing the substrate;
A gas supply nozzle having a gas supply hole for supplying a processing gas into the processing chamber,
The gas supply nozzle is a substrate processing apparatus in which an inner surface of the nozzle is coated with a protective film formed of TaC or pyrolytic carbon.

[Appendix 10]
Carrying a substrate holding tool holding a plurality of substrates into a processing chamber;
A step of supplying the processing gas by a gas supply nozzle having a gas supply hole for supplying a processing gas into the processing chamber and having a nozzle inner surface coated with a protective film formed of TaC or pyrolytic carbon;
A substrate processing method comprising:

[Appendix 11]
Carrying a substrate holding tool holding a plurality of substrates into a processing chamber;
A step of supplying the processing gas by a gas supply nozzle having a gas supply hole for supplying a processing gas into the processing chamber and having a nozzle inner surface coated with a protective film formed of TaC or pyrolytic carbon;
A method for manufacturing a semiconductor device, comprising:

10 Semiconductor manufacturing equipment (substrate processing equipment)
14 Substrate (wafer)
30 Substrate holder (boat)
45 Processing chambers 60, 70 Gas supply nozzles 68, 72 Gas supply holes 80 Tubular member 82 Lid member 84 Protective film

Claims (1)

A substrate holder for vertically stacking and holding a plurality of substrates;
A processing chamber for carrying in the substrate holder and processing the substrate;
A gas supply nozzle having a gas supply hole for supplying a processing gas into the processing chamber,
The gas supply nozzle is a substrate processing apparatus in which an inner surface of the nozzle is coated with a protective film formed of TaC or pyrolytic carbon.

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