Substrate Processing Apparatus, Method for Manufacturing Semiconductor Device, and Storage Medium

Abstract

The present invention improves the inter-plane and intra-plane uniformity of a film formed on a substrate. The invention comprises: a substrate holder for arranging and holding substrates; and a reaction tube for housing the substrate holder. The substrate holder comprises: a plurality of columns extending around the arranged substrates in a direction substantially perpendicular to the substrates; a top plate for fixing one end of each of the plurality of columns to each other and having an opening at the center; and a bottom plate for fixing the other ends of each of the plurality of columns to each other. The reaction tube comprises a protrusion with a flat front end protruding inward in a shape corresponding to the shape of the opening. The protrusion is arranged to be inserted into the opening when the substrate holder is housed in the reaction tube and is closer to the substrate disposed closest to the top plate than the top plate.

Description

Technical Field

[0001] The present invention relates to a substrate processing device, a method for manufacturing a semiconductor device, and a storage medium. Background Art

[0002] Patent Document 1 describes a substrate processing apparatus that forms a film on the surface of a substrate while holding substrates in multiple layers on substrate holders within a processing furnace.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2019-165210 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] In order to safely move the substrate holder into and out of a processing furnace such as the one described above, and to rotate it, a gap must be created between the top plate of the substrate holder and the inner surface of the reaction tube of the processing furnace in which it is housed. Furthermore, product substrates, used as products, have a larger surface area than monitor or dummy substrates, which are not used as products. Consequently, the consumption of processing gas during substrate processing is higher.

[0008] Therefore, residual gas generated in the gap between the top plate of the substrate holder and the inner surface of the reaction tube may deteriorate the uniformity of the formed film. This deterioration in uniformity is called a loading effect.

[0009] An object of the present invention is to improve the inter-plane and in-plane uniformity of a film formed on a substrate.

[0010] Solutions to Problems

[0011] According to a first embodiment of the present invention, the following technology is provided, comprising:

[0012] a substrate holder that arranges and holds the substrate; and

[0013] a reaction tube which accommodates the substrate holder therein,

[0014] The substrate holder has:

[0015] a plurality of pillars extending around the arranged substrates in a direction substantially perpendicular to the substrates;

[0016] a top plate that fixes one end of each of the plurality of columns to each other and has an opening in the center; and

[0017] a bottom plate, which fixes the other ends of the plurality of columns to each other,

[0018] The reaction tube has a protruding portion with a flat front end protruding inward in a shape corresponding to the shape of the opening.

[0019] The protrusion is provided so as to be inserted into the opening when the substrate holder is accommodated in the reaction tube and to be closer to the substrate disposed closest to the top plate than to the top plate.

[0020] Effects of the Invention

[0021] According to the present invention, the inter-plane and in-plane uniformity of a film formed on a substrate can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic structural diagram of a substrate processing apparatus 101 according to one embodiment of the present invention.

[0023] Figure 2 It is a side cross-sectional view of the processing furnace 202 according to one embodiment of the present invention.

[0024] Figure 3 This is a diagram showing a control flow according to one embodiment of the present invention.

[0025] Figure 4 This is a perspective view of a substrate holder according to one embodiment of the present invention.

[0026] Figure 5 This is a perspective view showing the relationship between a substrate holder and an inner tube according to one embodiment of the present invention.

[0027] Figure 6 (A) is a side cross-sectional view for explaining the relationship between the substrate holder and the inner tube according to one embodiment of the present invention. Figure 6 (B) is used to illustrate Figure 6 An enlarged view of the periphery of the recess 204c in (A).

[0028] Figure 7 It is a side cross-sectional view showing a modified example of the inner tube according to one embodiment of the present invention.

[0029] Figure 8 This is a side cross-sectional view showing a modified example of the reaction tube according to one embodiment of the present invention.

[0030] Figure 9 (A) is a diagram showing the distribution of SiCl2 partial pressure in a processing furnace when Si2Cl6 gas is supplied to a wafer using a processing furnace of a comparative example; Figure 9(B) is a diagram showing the distribution of SiCl 2 partial pressure in the processing furnace 202 when Si 2 Cl 6 gas is supplied to the wafer using the processing furnace 202 of this embodiment.

[0031] Figure 10 (A) is a graph showing the wafer surface uniformity evaluated by evaluating the average value of the SiCl 2 partial pressure on the wafer in each slot number when Si 2 Cl 6 gas was supplied to the wafer using the processing furnace of the comparative example and the processing furnace 202 of this embodiment. Figure 10 (B) is a graph showing the wafer surface uniformity comparing the values obtained by dividing the difference between the wafer center and the wafer end in each slot number by the average value when Si2Cl6 gas is supplied to the wafer using the processing furnace of the comparative example and the processing furnace 202 of this embodiment. DETAILED DESCRIPTION

[0032] <One embodiment of the present invention>

[0033] Hereinafter, one embodiment of the present invention will be described.

[0034] (1) Structure of substrate processing apparatus

[0035] First, refer to Figure 1 、 Figure 2 The structure of the substrate processing apparatus 101 according to this embodiment will be described. Figure 1 It is a schematic structural diagram of a substrate processing apparatus 101 according to one embodiment of the present invention. Figure 2 2 is a side cross-sectional view of a processing furnace 202 according to an embodiment of the present invention. The substrate processing apparatus 101 according to this embodiment is configured as a vertical apparatus for performing oxidation, diffusion processing, thin film formation processing, etc. on substrates such as wafers.

[0036] (Overall structure)

[0037] like Figure 1 As shown, the substrate processing apparatus 101 is configured as a batch-type vertical heat treatment apparatus. The substrate processing apparatus 101 includes a frame 111 in which main parts such as a processing furnace 202 are provided. A wafer box (also called a FOUP (wafer transfer box)) 110 is used as a substrate transport container (wafer carrier) into the frame 111. The wafer box 110 is configured to accommodate, for example, 25 wafers 200, which are substrates composed of silicon (Si) or silicon carbide (SiC), etc. A wafer box carrier 114 is arranged on the front side of the frame 111. The wafer box 110 is configured to be placed on the wafer box carrier 114 in a closed state.

[0038] On the front side of the frame 111 ( Figure 1A wafer box transfer device 118 is provided at a position (on the right side in the figure) and opposite to the wafer box carrier 114. A wafer box carrier 105 and a wafer box opener and a wafer number detector (not shown) are provided near the wafer box transfer device 118. The wafer box carrier 105 is arranged above the wafer box opener and is configured to hold a plurality of wafer boxes 110 while being loaded thereon. The wafer number detector is provided adjacent to the wafer box opener. The wafer box transfer device 118 is composed of a wafer box elevator 118a that can be raised and lowered while holding the wafer box and a wafer box transfer mechanism 118b that serves as a transfer mechanism. The wafer box transfer device 118 is configured to transfer the wafer box 110 between the wafer box carrier 118, the wafer box carrier 105 and the wafer box opener through the continuous operation of the wafer box elevator 118a and the wafer box transfer mechanism 118b. The cassette opener is configured to open the lid of the cassette 110. The wafer count detector is configured to detect the number of wafers 200 in the cassette 110 with the lid opened.

[0039] A wafer transfer machine 125 and a wafer boat 217 serving as a substrate holder are installed within the housing 111. The wafer transfer machine 125 includes an arm (tweezers) 125c, which is capable of vertical movement and horizontal rotation by a drive unit (not shown). The arm 125c is configured to simultaneously remove, for example, five wafers. The arm 125c is moved to transfer wafers 200 between the wafer cassette 110 positioned at the cassette opener and the wafer boat 217.

[0040] Next, the operation of the substrate processing apparatus 101 according to this embodiment will be described.

[0041] First, using an intra-process transfer device (not shown), the wafer cassette 110 is placed on the cassette stage 114, with the wafers 200 in a vertical position and the wafer inlet and outlet of the cassette 110 facing upward. The cassette stage 114 then rotates the wafer cassette 110 90 degrees in the longitudinal direction toward the rear of the housing 111. As a result, the wafers 200 in the cassette 110 are in a horizontal position, with the wafer inlet and outlet of the cassette 110 facing rearward within the housing 111.

[0042] Next, the wafer box 110 is automatically transported and delivered to a designated shelf position of the wafer box carrier 105 by the wafer box transport device 118 and temporarily stored. It is then transferred from the wafer box carrier 105 to the wafer box opener or directly transported to the wafer box opener.

[0043] Once the wafer cassette 110 is transferred to the cassette opener, the cassette 110 opens its lid. The wafer count detector then detects the number of wafers within the opened cassette 110. Wafers 200 are picked up from the cassette 110 via the wafer inlet and outlet by the arm 125c of the wafer transfer machine 125 and loaded (or loaded) onto the wafer boat 217 through the transfer operation of the wafer transfer machine 125. The wafer transfer machine 125, having delivered the wafer 200 to the wafer boat 217, returns to the cassette 110 and loads the next wafer 200 onto the wafer boat 217.

[0044] When a predetermined number of wafers 200 are loaded into the wafer boat 217, the lower end of the processing furnace 202 closed by the furnace gate 147 is opened through the furnace gate 147. Then, the sealing cover 219 is moved by the wafer boat elevator 115 (see FIG. Figure 2 ) rises, thereby moving the wafer boat 217 holding the wafer 200 group into the processing furnace 202 (wafer boat introduction). After introduction, the wafers 200 are subjected to any processing in the processing furnace 202. This processing will be described later. After processing, the wafers 200 and the wafer cassette 110 are moved out of the processing furnace 202 (wafer boat export). The wafers 200 are removed from the wafer boat 217 (unloaded) in the reverse order of the above steps and exported to the outside of the housing 111.

[0045] (Structure of treatment furnace)

[0046] Next, use Figure 2 The structure of the processing furnace 202 of this embodiment will be described.

[0047] (Processing Room)

[0048] like Figure 2As shown, the processing furnace 202 includes a reaction tube 203 constituting a processing container. The reaction tube 203 includes an inner tube 204 as an inner tube and an outer tube 205 as an outer tube arranged on the outside thereof. The inner tube 204 is made of a heat-resistant material such as quartz (SiO2) or silicon carbide (SiC). As will be described in detail later, the inner tube 204 is formed in a cylindrical shape with a closed upper end and an open lower end. The inner tube 204 has a processing chamber 201 formed therein for performing a process of forming a thin film on the wafer 200. The processing chamber 201 is configured to accommodate the wafers 200 in a state where they are arranged in multiple layers in a horizontal posture in the vertical direction by a wafer boat 217. The inner tube 204 has one or more protrusions 207 extending from the outer peripheral surface toward the outer tube 205 side and formed by protruding the side toward the outside. A nozzle chamber 201a extending vertically is formed within the raised portion 207. The nozzle chamber 201a houses nozzles 230b and 230c, described later. Furthermore, the inner tube 204 has an outlet 215 on its outer peripheral surface opposite the nozzle chamber 201a, which opens at a position facing the arrayed wafers and allows ambient gas to flow into a cylindrical space 250 between the inner tube 204 and the outer tube 205.

[0049] The outer tube 205 has a pressure-resistant structure and accommodates the inner tube 204 in an airtight manner. In addition, the outer tube 205 can be arranged concentrically with the inner tube 204. The inner diameter of the outer tube 205 is larger than the outer diameter of the inner tube 204, and is formed into a cylindrical shape with a closed upper end and an open lower end. The outer tube 205 is made of a heat-resistant material such as quartz or silicon carbide. In such a structure of a reaction tube, the flow (convection) of the gas formed parallel to the respective surfaces of the plurality of wafers 200 is dominant in the movement of substances near the surface. In this case, the reaction tube 203 is called a cross-flow reaction tube.

[0050] (nozzle)

[0051] Nozzles 230b and 230c extend parallel to the arrangement axis (arrangement direction) of the wafers 200 and are disposed within the raised portion 207. Nozzles 230b and 230c may also be disposed in the arc-shaped space between the inner wall of the inner tube 204 and the wafers 200. Nozzles 230b and 230c may be formed, respectively, of a U-shaped quartz tube with a closed front end and a linear quartz tube. Gas supply holes 234b and 234c are provided on the sides of nozzles 230b and 230c, respectively, as gas supply ports for supplying gas to each of the arranged wafers 200. The gas supply holes 234b and 234c have opening areas that are the same from bottom to top, or have an inclined size, and are provided in multiple locations at equal intervals. The upstream ends of nozzles 230b and 230c are connected to the downstream ends of gas supply pipes 232b and 232c, respectively. In addition, the nozzles 230b and 230c are configured to not have gas supply holes 234b and 234c at positions corresponding to multiple arrangement positions surrounded by the cover 400 described later. In addition, the nozzles 230b and 230c are configured to have gas supply holes 234b and 234c at positions corresponding to multiple wafers 200 such as product substrates or monitoring substrates held at multiple arrangement positions between the cover 400 described later and the top plate 211. In such a structure of the processing chamber and the nozzle, the gas flow (convection) formed parallel to the respective surfaces of the multiple wafers 200 is dominant in the movement of substances near the surface. At this time, the reaction tube 203 is called a cross-flow reaction tube.

[0052] (Heater)

[0053] Outside the reaction tube 203, a heater 206, serving as a furnace body, is concentrically arranged around the sidewalls and top of the reaction tube 203. The heater 206 is cylindrical in shape and vertically supported by a heater base (not shown), serving as a retaining plate. A temperature sensor 263, serving as a temperature detector, is located within the reaction tube 203 (e.g., between the inner tube 204 and the outer tube 205, or inside the inner tube 204). The heater 206 and the temperature sensor 263 are electrically connected to a temperature control unit 238, described later. The temperature control unit 238 is configured to control the power supply to the heater 206 at predetermined timings based on temperature information detected by the temperature sensor 263, so that the temperature within the processing chamber 201 maintains a predetermined temperature profile.

[0054] (Manifold)

[0055] A manifold (air inlet adapter) 209 is provided below the outer tube 205 and is concentric with the outer tube 205. The manifold 209 is made of, for example, stainless steel. The manifold 209 is formed into a cylindrical shape with an open upper end and a closed lower end. The manifold 209 is configured to engage with the lower end of the inner tube 204 and the lower end of the outer tube 205, respectively, or to support the lower end of the inner tube 204 and the lower end of the outer tube 205, respectively. In addition, an O-ring 220a is provided as a sealing member between the manifold 209 and the outer tube 205. The manifold 209 is supported by a heater base (not shown), thereby placing the reaction tube 203 in a vertically mounted state. The processing container is mainly formed by the reaction tube 203 and the manifold 209.

[0056] (Jingzhou)

[0057] Inside the reaction tube 203 and the processing chamber 201, a wafer boat 217, serving as a substrate holder, is loaded and stored from below the lower opening of the manifold 209. The wafer boat 217 is made of a heat-resistant material such as quartz or silicon carbide. As described in detail later, the wafer boat 217 includes: a plurality of columns, for example, three columns 212; a ring-shaped top plate 211 with an opening at the center of the upper ends of the three columns 212, which are fixed to each other; and a circular bottom plate 210, which fixes the lower ends of the three columns 212 to each other. The wafer boat 217 is configured to hold a plurality of wafers 200 arranged at predetermined intervals in a horizontal position with their centers aligned with each other. Furthermore, the wafer boat 217 is configured to hold a plurality of heat insulation plates 216, which are circular heat insulation members, arranged at predetermined intervals in a horizontal position with their centers aligned with each other, below the wafer processing area where the wafers 200 are arranged. The heat insulating plate 216 is made of a heat-resistant material such as quartz or silicon carbide, and is configured to prevent heat from the heater 206 from being transferred to the manifold 209 .

[0058] Furthermore, a cover 400 is provided below the wafer boat 217 and above the heat-insulating area where the heat shield 216 is stored, which is located below the wafer processing area. The cover 400 surrounds the wafer boat 217 from the top and sides, encompassing multiple arrangement positions (also known as loading positions) within the wafer 200 arrangement positions (also known as the loading positions), including the arrangement position closest to the base plate 210. The wafer boat 217 does not hold wafers 200, such as product substrates or monitor substrates, at the multiple arrangement positions surrounded by the cover 400. These arrangement positions correspond to positions where dummy substrates have been placed in the past due to inability to achieve sufficient uniformity. Furthermore, the wafer boat 217 is configured to hold multiple wafers 200, such as product substrates or monitor substrates, at the multiple arrangement positions between the cover 400 and the top plate 211.

[0059] (Carrier gas supply system)

[0060] Nozzles 230b and 230c are provided on the sidewalls of manifold 209 so as to communicate with the interior of process chamber 201. Nozzles 230b and 230c are provided for supplying, for example, nitrogen (N2) as a carrier gas into process chamber 201. A carrier gas source 300a, a mass flow controller 241a serving as a flow controller (flow control unit), and a valve 310a are provided in order from the upstream side of gas supply pipe 232a. This structure enables control of the flow rate of the carrier gas supplied into process chamber 201 via gas supply pipe 232a, as well as the concentration and partial pressure of the carrier gas within process chamber 201.

[0061] The gas flow control unit 235 described later is electrically connected to the valve 310a and the mass flow controller 241a and is configured to control the start, stop, and supply flow rate of the carrier gas into the processing chamber 201 at predetermined timings.

[0062] The carrier gas supply system of this embodiment mainly comprises valve 310a, mass flow controller 241a, gas supply pipe 232a, gas supply pipe 232b, nozzle 230b, gas supply pipe 232c, and nozzle 230c. Alternatively, the carrier gas supply system may include carrier gas source 300a.

[0063] (Si raw material gas supply system)

[0064] A nozzle 230b, which supplies hexachlorodisilane (Si2Cl6, abbreviated as HCDS) gas as an example of a raw material gas (Si-containing gas) into the processing chamber 201, is disposed on the sidewall of the manifold 209 so as to communicate with the interior of the processing chamber 201. The upstream end of the nozzle 230b is connected to the downstream end of a gas supply pipe 232b. A Si raw material gas source 300b, a mass flow controller 241b, and a valve 310b are disposed in the gas supply pipe 232b in order from the upstream side. This structure enables control of the flow rate of the Si raw material gas supplied into the processing chamber 201, as well as the concentration and partial pressure of the Si raw material gas within the processing chamber 201.

[0065] The gas flow control unit 235 described later is electrically connected to the valve 310b and the mass flow controller 241b and is configured to control the start, stop, and supply flow rate of the Si source gas into the processing chamber 201 at predetermined timings.

[0066] The Si raw material gas supply system of this embodiment mainly comprises valve 310b, mass flow controller 241b, gas supply pipe 232b, and nozzle 230b. Alternatively, the Si raw material gas supply system may include Si raw material gas source 300b.

[0067] (Nitriding raw material gas supply system)

[0068] A nozzle 230c, which supplies a gas such as ammonia (NH3), nitrogen (N2), nitrous oxide (N2O), or monomethylhydrazine (CH6N2) as a modification raw material (reaction gas or reactant) into the process chamber 201, is disposed on a sidewall of the manifold 209 in communication with the process chamber 201. The upstream end of the nozzle 230c is connected to the downstream end of a gas supply pipe 232c. A nitriding raw material gas source 300c, a mass flow controller 241c, and a valve 310c are disposed in the gas supply pipe 232c in this order from the upstream side. This structure enables control of the flow rate of the nitriding raw material gas supplied into the process chamber 201, as well as the concentration and partial pressure of the nitriding raw material gas within the process chamber 201.

[0069] The gas flow control unit 235 described later is electrically connected to the valve 310c and the mass flow controller 241c and is configured to control the start, stop, and supply flow rate of the nitriding source gas into the processing chamber 201 at predetermined timings.

[0070] The nitriding source gas supply system of this embodiment mainly comprises a valve 310c, a mass flow controller 241c, a gas supply pipe 232c, and a nozzle 230c. Alternatively, the nitriding source gas supply system may include a nitriding source gas source 300c.

[0071] Furthermore, the gas supply system of this embodiment is mainly composed of a Si raw material gas supply system, a nitriding raw material gas supply system, and a carrier gas supply system.

[0072] (Exhaust System)

[0073] An exhaust pipe 231 for exhausting the interior of the processing chamber 201 is provided on the side wall of the manifold 209. Exhaust pipe 231 extends through the side of the manifold 209 and communicates with the lower end of a cylindrical space 250, which serves as an exhaust space and is formed by the gap between the inner tube 204 and the outer tube 205. On the downstream side of the exhaust pipe 231 (the side opposite to the connection to the manifold 209), a pressure sensor 245 serving as a pressure detector, an APC (Auto Pressure Controller) valve 242 serving as a pressure adjustment device, and a vacuum pump 246 are provided, in order from the upstream side.

[0074] The pressure control unit 236, described later, is electrically connected to the pressure sensor 245 and the APC valve 242. The pressure control unit 236 is configured to control the opening of the APC valve 242 based on the pressure information detected by the pressure sensor 245 so that the pressure within the processing chamber 201 reaches a predetermined pressure (vacuum level) at a predetermined timing. The APC valve 242 is an on-off valve that can be opened and closed to evacuate the processing chamber 201 and to stop evacuation, and can also be adjusted to adjust the pressure by adjusting the valve opening.

[0075] The exhaust system of this embodiment mainly comprises an exhaust pipe 231, a pressure sensor 245, and an APC valve 242. In addition, the exhaust system may include a vacuum pump 246, and further, a collection device and a detoxification device.

[0076] (Sealing cover)

[0077] A sealing cap 219 is provided at the lower opening of the manifold 209, airtightly sealing the opening for transporting wafer boats 217 into and out of the processing vessel. The sealing cap 219 is formed of a metal such as stainless steel and is disc-shaped. An O-ring 220b, serving as a sealing member, is provided on the upper surface of the sealing cap 219 and engages with the lower end of the manifold 209. The sealing cap 219 is configured to abut the lower end of the manifold 209 from the vertically lower side of the reaction vessel, sandwiching the O-ring 220b. The O-ring 220b seals the reaction tubes 203 and the sealing cap 219, preventing direct contact between the reaction tubes 203 and the sealing cap 219. The O-ring 220b provides a sufficient seal when compressed to a desired degree of collapse. While the desired degree of collapse may vary depending on the degradation of the O-ring 220b, this degree of collapse is significantly smaller than the spacing between the wafers 200. If the manifold 209 and the seal cap 219 are in direct contact with each other, particles are generated, which is not preferable. Therefore, a buffer member that does not have sealing properties may be provided on the outer periphery of the O-ring 220b.

[0078] (Rotation mechanism)

[0079] A rotating mechanism 254 for rotating the wafer boat 217 is provided below the sealing cover 219 (i.e., on the side opposite to the processing chamber 201). The rotating mechanism 254 holds the wafer boat 217. The rotating shaft 255 of the rotating mechanism 254 is provided so as to pass through the sealing cover 219. The upper end of the rotating shaft 255 rotatably supports the wafer boat 217 from below. The structure is such that the wafer boat 217 and the wafers 200 can be rotated in the processing chamber 201 by operating the rotating mechanism 254. In addition, in order to make the rotating shaft 255 less susceptible to the influence of the processing gas, an inert gas supply system (not shown) is used to flow an inert gas near the rotating shaft 255 to protect it from the influence of the processing gas.

[0080] (Jingzhou Lift)

[0081] The seal cap 219 is configured to be vertically elevated by a boat elevator 115, which is a vertically disposed elevating mechanism outside the reaction tube 203. The boat elevator 115 is configured to operate to move the wafer boat 217 into and out of the processing chamber 201 (introducing or unloading the wafer boat).

[0082] The drive control unit 237 is electrically connected to the rotation mechanism 254 and the boat elevator 115. The drive control unit 237 is configured to control the rotation mechanism 254 and the boat elevator 115 at predetermined timing so as to perform predetermined operations.

[0083] (Controller)

[0084] The gas flow control unit 235, pressure control unit 236, drive control unit 237, and temperature control unit 238 are electrically connected to a main control unit 239 that controls the entire substrate processing apparatus 101. The controller 240, which serves as a control unit in this embodiment, is primarily composed of the gas flow control unit 235, pressure control unit 236, drive control unit 237, temperature control unit 238, and main control unit 239.

[0085] The controller 240 is an example of a control unit (control unit) that controls the overall operation of the substrate processing device 101, and controls the flow adjustment of the mass flow controllers 241a, 241b, and 241c, the opening and closing of the valves 310a, 310b, and 310c, the opening and closing of the APC valve 242 and the pressure adjustment action based on the pressure sensor 245, the temperature adjustment action of the heater 206 based on the temperature sensor 263, the start / stop of the vacuum pump 246, the rotation speed adjustment of the rotating mechanism 254, the lifting and lowering action of the wafer boat elevator 115, etc.

[0086] (2) Method for manufacturing a semiconductor device

[0087] Next, an example of a method for forming an insulating film on a wafer 200, such as during the manufacture of a large-scale integrated circuit (LSI), will be described using the processing furnace 202 of the substrate processing apparatus 101 as part of a semiconductor device manufacturing process. In the following description, the operations of the various components comprising the substrate processing apparatus 101 are controlled by a controller 240.

[0088] In this embodiment, a method of forming a SiN film as a silicon nitride film on the wafer 200 will be described.

[0089] First, a Si source gas and a reaction gas (nitriding source gas) are alternately supplied to form a SiN film on the wafer 200 .

[0090] In this embodiment, an example of a nitriding raw material gas using Si 2 Cl 6 gas as a Si raw material gas and using NH 3 gas as a reaction gas is described.

[0091] Figure 3 An example of the control flow of this embodiment is shown. First, if a plurality of wafers 200 are loaded into the wafer boat 217 (wafer loading), the wafer boat 217 loaded with the plurality of wafers 200 is lifted by the wafer boat elevator 115 and moved into the processing chamber 201 (wafer boat introduction), and the wafer boat 217 loaded with the plurality of wafers 200 is stored inside the reaction tube 203. In this state, the sealing cover 219 is in a state of sealing the lower end of the reaction tube 203 via the O-ring 220b. Furthermore, in the film forming process, the controller 240 controls the substrate processing device 101 as follows. That is, the heater 206 is controlled to maintain the temperature in the processing chamber 201 in a range of, for example, 300°C to 600°C, for example, 600°C. Then, the wafer boat 217 is rotated by the rotating mechanism 254 to rotate the wafers 200. Then, the following process is performed: the vacuum pump 246 is operated and the APC valve 242 is opened to evacuate the processing chamber 201. After the temperature of the wafer 200 reaches 600°C and the temperature and other parameters are stabilized, the temperature in the processing chamber 201 is maintained at 600°C, and the following steps are performed in sequence to process the wafer 200.

[0092] (Step 11)

[0093] In step 11, Si2Cl6 gas is flowed. Si2Cl6 is in liquid form at room temperature. When supplied to the processing chamber 201, there are methods such as heating to vaporize it and then supplying it, and using a vaporizer (not shown) to pass an inert gas called a carrier gas such as He (helium), Ne (neon), Ar (argon), or N2 (nitrogen) through a container filled with Si2Cl6 gas, and then supplying the vaporized portion together with the carrier gas to the processing chamber 201. The latter method is used as an example for description.

[0094] Si2Cl6 gas is flowed into gas supply pipe 232b, and carrier gas (N2 gas) is flowed into carrier gas supply pipe 232a connected to gas supply pipe 232b. Valve 310b of gas supply pipe 232b, valve 310a of carrier gas supply pipe 232a connected to nozzle 230b, and APC valve 242 of exhaust pipe 231 are all opened simultaneously. Carrier gas flows out of carrier gas supply pipe 232a, and its flow rate is adjusted by mass flow controller 241a. Si2Cl6 gas flows out of gas supply pipe 232b, and its flow rate is adjusted by mass flow controller 241b. It is vaporized by a vaporizer (not shown), mixed with the flow-adjusted carrier gas, and supplied into processing chamber 201 through gas supply hole 234b of nozzle 230b. It is then exhausted through exhaust pipe 231. At this point, APC valve 242 is appropriately adjusted to maintain the pressure within processing chamber 201 within a range of 20 to 60 Pa, for example, 53 Pa. The supply rate of Si2Cl6 gas controlled by mass flow controller 241b is 0.3 slm. In addition, N2 gas is simultaneously supplied as a carrier gas from carrier gas supply pipe 232a connected to gas supply pipe 232b. The supply rate of N2 gas controlled by mass flow controller 241a of carrier gas supply pipe 232a connected to gas supply pipe 232b is, for example, 1 slm. The wafer 200 is exposed to Si2Cl6 gas for 3 to 10 seconds. At this time, the temperature of heater 206 is set so that the temperature of the wafer is within the range of 300°C to 600°C, for example, 600°C.

[0095] At this time, the gases flowing into the processing chamber 201 are only Si2Cl6 gas and inert gases such as N2 gas and Ar gas, and there is no NH3 gas. Therefore, the Si2Cl6 gas will not cause a gas phase reaction, and will react with the surface of the wafer 200 or the base film (chemical adsorption) to form an adsorption layer of the raw material (Si2Cl6) or a Si layer (hereinafter referred to as the Si-containing layer). In addition to the continuous adsorption layer of the raw material molecules, the adsorption layer of Si2Cl6 also includes a discontinuous adsorption layer. In addition to the continuous layer composed of Si, the Si layer also includes a Si thin film formed by the overlap of them. In addition, the continuous layer composed of Si is sometimes also referred to as a Si thin film.

[0096] At the same time, opening valve 310a to allow inert gas to flow out of carrier gas supply pipe 232a connected to gas supply pipe 232c prevents SiCl gas from bypassing the NH gas supply side described later. The N gas supply flow rate is controlled by mass flow controller 241a of carrier gas supply pipe 232a connected to gas supply pipe 232c, for example, at 0.1 slm.

[0097] (Step 12)

[0098] The valve 310b of the gas supply pipe 232b is closed to stop the supply of Si2Cl6 gas to the processing chamber 201. At this time, the APC valve 242 of the exhaust pipe 231 is opened, and the processing chamber 201 is evacuated to below 20 Pa by the vacuum pump 246, thereby removing the residual Si2Cl6 from the processing chamber 201. At this time, if an inert gas such as N2 is supplied to the processing chamber 201, the effect of removing the residual Si2Cl6 can be further improved.

[0099] (Step 13)

[0100] In step 13, NH3 gas is flowed. NH3 gas is flowed to the gas supply pipe 232c, and carrier gas (N2 gas) is flowed to the carrier gas supply pipe 232a connected to the gas supply pipe 232c. The valve 310c of the gas supply pipe 232c, the valve 310a of the carrier gas supply pipe 232a, and the APC valve 242 of the exhaust pipe 231 are all opened simultaneously. The carrier gas flows out of the carrier gas supply pipe 232a, and the flow rate is adjusted by the mass flow controller 241a. NH3 gas flows out of the gas supply pipe 232c, and the flow rate is adjusted by the mass flow controller 241c. It is then mixed with the flow-adjusted carrier gas, supplied into the processing chamber 201 from the gas supply hole 234c of the nozzle 230c, and exhausted from the exhaust pipe 231. When the NH3 gas is flowed, the APC valve 242 is appropriately adjusted to maintain the pressure in the processing chamber 201 within the range of 50 to 1000 Pa, for example, 60 Pa. The NH3 gas supply flow rate controlled by the mass flow controller 241c is 1 to 10 slm. The wafer 200 is exposed to the NH3 gas for 10 to 30 seconds. The temperature of the heater 206 is set to a predetermined temperature in the range of 300°C to 600°C, for example, 600°C.

[0101] At the same time, if the on-off valve 310a is opened to allow the inert gas to flow out from the carrier gas supply pipe 232a connected to the gas supply pipe 232b, it is possible to prevent the NH3 gas from bypassing the Si2Cl6 gas supply side.

[0102] By supplying the NH 3 gas, the Si-containing layer chemically adsorbed on the wafer 200 undergoes a surface reaction (chemical adsorption) with the NH 3 , thereby forming a SiN film on the wafer 200 .

[0103] (Step 14)

[0104] In step 14, valve 310c of gas supply pipe 232c is closed to stop the supply of NH3 gas. Furthermore, APC valve 242 of exhaust pipe 231 is kept open, and vacuum pump 246 is used to evacuate process chamber 201 to below 20 Pa, thereby removing residual NH3 gas from process chamber 201. Furthermore, at this time, if an inert gas such as N2 gas is supplied to process chamber 201 from gas supply pipe 232c, which supplies NH3 gas, and gas supply pipe 232b, which supplies Si2Cl6 gas, respectively, to perform a purge, the removal of residual NH3 gas can be further enhanced.

[0105] The above steps 11 to 14 constitute one cycle, and by performing them at least once, a SiN film having a predetermined thickness is formed on the wafer 200. At this time, as described above, care must be taken in each cycle to ensure that the atmosphere composed of the Si source gas in step 11 and the atmosphere composed of the nitride source gas in step 13 are not mixed within the processing chamber 201.

[0106] The thickness of the SiN film can be adjusted to about 1 to 5 nm by controlling the number of cycles. The SiN film formed at this time becomes a continuous film with a smooth and dense surface.

[0107] (3) Next, use Figure 4 、 Figure 5 、 Figure 6 (A) and Figure 6 (B) further details the wafer boat 217 and the internal tube 204 that accommodates the wafer boat 217.

[0108] As mentioned above, Figure 4 As shown, the wafer boat 217 has: a plurality of columns 212, which extend around the arranged wafers 200 in a direction approximately perpendicular to the wafers 200 and have approximately the same length; an annular top plate 211, which has an opening in the center near the upper ends of the plurality of columns 212 fixed to each other; and a circular plate-shaped bottom plate 210, which fixes the plurality of columns 212 to each other near the lower ends. That is, three columns 212 are arranged between the bottom plate 210 and the top plate 211 of the wafer boat 217 at intervals of approximately 90 degrees. The wafer boat 217 is designed to have sufficient strength to withstand the stress applied when the horizontal wafer boat 217 is grasped at a determined position to stand up, and the stress applied when the upright wafer boat 217 is lifted and transported. In addition, as Figure 5 As shown (in Figure 4(Not shown in the figure), a plurality of support pins 221 are provided on each column 212 as support members for holding the wafer 200 approximately horizontally. Each support pin 221 is provided so as to extend approximately horizontally toward the inner periphery of each of the three columns 212. In addition, a plurality of support pins 221 are provided on each of the three columns 212 at predetermined intervals (pitch).

[0109] Cover 400 comprises an upper panel 401 and a cylindrical side panel 402. Inside, a disc-shaped quartz plate 403 is placed as a dummy substrate. Upper panel 401 is welded airtightly to pillars 212, which have holes extending through them. Furthermore, it can be seamlessly welded to side panel 402 along its entire circumference. Quartz plate 403 can be welded to pillars 212 before installing cover 400. Cover 400 may also have a bottom surface; in this case, vent holes are provided on the bottom surface to prevent the interior from being sealed. Side panel 402 can also be split into three to prevent interference with pillars 212.

[0110] The inner tube 204 has a top portion 204a that is closed at the upper end and terminates the upper portion of the inner tube 204 at one end in the direction of loading and arranging the wafers 200. The outer surface side (upper surface side) of the top portion 204a is flat, and a convex portion 204b as a protrusion that protrudes inward in a cylindrical shape is provided on the inner surface side of the top portion 204a. The front end of the convex portion 204b is in the shape of a flat cylinder, or it can be said that the front end is in the shape of being extruded along the arrangement axis of the wafers 200. An annular recess (groove) 204c is formed around the convex portion 204b and between the outer peripheral surface of the inner tube 204 and the convex portion 204b. As Figure 6 As shown in (A), the convex portion 204b is smaller than the opening of the top plate 211 of the wafer boat 217. In other words, the outer diameter of the convex portion 204b is smaller than the inner diameter of the top plate 211. Furthermore, the inner diameter of the concave portion 204c is smaller than the inner diameter of the top plate 211. Furthermore, the outer diameter of the concave portion 204c is configured to be larger than the outer diameter of the top plate 211. In other words, the entire inner surface of the top portion 204a of the inner tube 204 follows the shape of the upper end (top plate 211) of the wafer boat 217, with a predetermined margin (gap).

[0111] Specifically, the inner surface of the top portion 204a of the inner tube 204 is shaped to correspond to the opening of the top plate 211. When the inner tube 204 houses the wafer boat 217, the top plate 211 of the wafer boat 217 fits within the recessed portion 204c of the inner tube 204, and the top plate 211 is positioned within the recessed portion 204c. Specifically, when the inner tube 204 houses the wafer boat 217, the protruding portion 204b of the inner tube 204 is inserted and inserted into the opening of the top plate 211 of the wafer boat 217. Since the top plate 211 is a ring with a rectangular cross-section (a rotating body formed by rotating the rectangle about the wafer arrangement axis), it has a square cross-section, and the corners of the recessed portion 204c also form square corners. In the inner tube 204, which requires little mechanical strength, there is no need to significantly round the corners to avoid stress concentration. Therefore, the recessed portion 204c can faithfully mimic the shape of the top plate 211. In addition, when the column 212 protrudes from the upper surface of the top plate 211, it can be regarded as a part of the top plate 211. Similarly, when the column 212 protrudes from the lower surface of the top plate 210, the part can be regarded as a part of the bottom plate 210. Figure 2 、 Figure 6 As shown, when the inner tube 204 accommodates the wafer boat 217, the protrusion 204b is positioned so as to be inserted into the opening of the top plate 211. In this case, the opening of the top plate 211 and the protrusion 204b of the inner tube 204 form a circle concentric with the rotation axis 255.

[0112] In addition, if Figure 6 As shown in FIG. 2A , the height H of the protrusion 204 b is set so that, when the wafer boat 217 loaded with wafers 200 is airtightly housed within the inner tube 204, that is, when the wafers 200 are being processed within the inner tube 204, the gap P1 between the tip of the protrusion 204 b and the wafer 200 closest to the top plate 211 and facing the protrusion 204 b is substantially equal to the gap P2 between adjacent wafers 200 within the wafer boat 217, that is, the spacing between wafers 200. Specifically, the height H of the protrusion 204 b is set so that, when the O-ring 220 b reaches a predetermined crushing amount sufficient for sealing, the gap P1 between the protrusion 204 b and the wafer 200 closest to the top plate 211 is substantially equal to the gap P2 between adjacent wafers 200 within the wafer boat 217. Furthermore, the height H of the protrusion 204b is set so that, when the O-ring 220b is crushed to a predetermined degree for sealability, the spacing between the protrusion 204b and the dummy substrate positioned closest to the top plate 211 is sufficiently smaller than the spacing P2 between adjacent wafers 200 within the wafer boat 217 and is greater than the variation in the predetermined crushing degree. Furthermore, the protrusion 204b is positioned so as to be inserted into the opening of the top plate 211 when the wafer boat 217 is housed within the reaction tube 203. This configuration allows the protrusion 204b to be closer to the wafer 200 positioned closest to the top plate 211 than to the top plate 211.

[0113] With the above structure, a narrow gap is formed around the convex portion 204b of the inner tube 204 and in the concave portion 204c of the top plate 211 of the wafer boat 217 to allow the wafer boat 217 to rise and rotate, thereby reducing the remaining gas space above the wafer boat 217.

[0114] By reducing the excess gas space above the wafer boat 217, variations in the amount of process gas supplied to the wafers 200 arranged vertically on the wafer boat 217 can be suppressed, and the partial pressure of the process gas supplied to the wafers 200 arranged vertically on the wafer boat 217 can be made uniform. This improves inter-surface uniformity of wafers such as large-surface-area product substrates.

[0115] Furthermore, by providing the cover 400 below the wafer boat 217 and above the insulation area where the insulation plates 216 are placed, the excess gas space below the wafer boat 217 can be reduced, thereby improving the inter-surface uniformity of the wafers and eliminating the need for a side dummy substrate.

[0116] In addition, when the wafer boat 217 is stored in the inner tube 204, Figure 6 As shown in (B), the height H is configured to be greater than the sum of the distance A1 from the bottom surface of the recessed portion 204c of the top 204a of the inner tube 204 to the upper surface of the top plate 211 of the wafer boat 217 and the thickness A2 of the top plate 211 in the height direction. Furthermore, the length B1 from the side surface of the protruding portion 204b of the inner tube 204 to the inner circumference of the top plate 211 is configured to be approximately equal to the length B2 from the outer circumference of the top plate 211 to the inner circumference of the inner tube 204. Furthermore, the distance A1 from the bottom surface of the recessed portion 204c of the top 204a of the inner tube 204 to the upper surface of the top plate 211 of the wafer boat 217 is configured to be smaller than either B1 or B2. In other words, the distance A1 provides an allowance for fluctuations in the dimensional accuracy of the wafer boat 217 and the amount of crushing of the O-ring 220a, and can therefore be kept small. The aforementioned gap P1 varies depending on the amount of O-ring 220a's collapse, but this variation is typically negligible. If the film quality of the substrate closest to the top plate is unstable, this substrate can be used as a dummy substrate. When using a wafer with a smaller surface area than the product substrate as a dummy substrate, setting gap P1 to be smaller than gap P2, for example, to the same value as gap A1, can reduce the residual gas space above the dummy substrate.

[0117] (4) Modification

[0118] Next, use Figure 7 、 Figure 8 A modification of the processing furnace 202 of this embodiment will be described.

[0119] Figure 7 The modification of the embodiment is different from the embodiment in the shape of the top portion 204a of the inner tube 204. In this modification, only the structure that is different from the inner tube 204 will be described.

[0120] The inner tube 304 of the modified example has a closed upper end and a top portion 304 a that terminates the inner tube 304 at one end in the direction in which the wafers 200 are stacked and arranged.

[0121] The top portion 304a has a cylindrical upper surface that is recessed inward, and a protruding portion 304b that protrudes inward in a cylindrical shape from the inner surface of the top portion 304a. The distal end of the protruding portion 304b is flat and cylindrical. A recessed portion 304c is formed around the protruding portion 304b and between the outer circumferential surface of the inner tube 304 and the protruding portion 304b. The outer diameter of the protruding portion 304b is smaller than the opening of the top plate 211 of the wafer boat 217, in other words, smaller than the inner diameter of the top plate 211. Furthermore, the inner diameter of the recessed portion 304c is smaller than the inner diameter of the top plate 211. Furthermore, the outer diameter of the recessed portion 304c is configured to be larger than the outer diameter of the top plate 211. Specifically, the inner surface of the top portion 304a of the inner tube 304 has a shape corresponding to that of the top plate 211. When the wafer boat 217 is housed within the inner tube 304, the top plate 211 is inserted into and positioned within the recess 304c. Specifically, whereas the top portion 204a of the inner tube 204 described above has a flat top surface, the top portion 304a of the inner tube 304 of the modified example has a recessed center and protrudes flatly inward.

[0122] like Figure 7 As shown, when the wafer boat 217 is housed within the reaction tube 203, the protrusion 304b is positioned to be inserted into the opening of the top plate 211. Specifically, the protrusion 304b is positioned so as to be inserted into the opening of the top plate 211 when the wafer boat 217 is housed within the reaction tube 203, and is configured to be closer to the wafers 200 positioned closest to the top plate 211 than to the top plate 211. For the same reasons as described above for the present embodiment, the corners of the protrusion 304b and recess 304c do not need to be intentionally chamfered and can be formed with angles. Furthermore, the wall thickness of the top portion 304a can be reduced to approximately the same thickness as the rest of the inner tube 304, assuming manufacturing difficulty and cost are not a concern.

[0123] As in the top 304a of this variant, the upper surface of the top 304a is concave and a convex portion 304b protruding inward is formed. By thinning the thickness of the top 304a, the heat capacity can be reduced compared to the top 204a of the above-mentioned embodiment, and the heat from the heater 206 can be easily conducted into the processing chamber 201.

[0124] Furthermore, by configuring the top portion 204 a of the present embodiment as described above, the heat capacity can be increased compared to the top portion 304 a of the modified example, thereby achieving a temperature buffering effect.

[0125] In addition, by making the quartz constituting the top 204a of the above-mentioned embodiment and the top 304a of the modified example opaque, the transmittance and thermal conductivity can be made different, making it difficult for heat from the heater 206 to be conducted into the processing chamber 201, or the heat capacity can be reduced.

[0126] Figure 8 The modified embodiment includes a single-tube reaction tube 503 in place of the double-tube reaction tube 203 consisting of the inner tube 204 and the outer tube 205 in the present embodiment. A protrusion 503b is formed on the top 503a of the reaction tube 503 in the same convex shape as the top 204a. This protrusion 503b fits into the opening of the top plate 211 of the wafer boat 217. Specifically, the protrusion 503b is positioned so as to be inserted into the opening of the top plate 211 when the wafer boat 217 is housed within the reaction tube 503. This configuration allows the protrusion 503b to be closer to the wafer 200 disposed closest to the top plate 211 of the wafer boat 217 than to the top plate 211.

[0127] (5) Simulation

[0128] Hereinafter, this embodiment will be described in comparison with a comparative example.

[0129] Compare the following situations: Use Figure 2 The processing furnace 202 of the present embodiment shown uses the above-mentioned semiconductor device manufacturing method to perform substrate processing on the wafer 200, which is a product substrate with an area 200 times larger than that of the bare wafer (hereinafter referred to as the present embodiment); and a processing furnace of a comparative example that differs only in that it does not have the protrusion 204b and the opening of the top plate 211, uses the above-mentioned semiconductor device manufacturing method to perform substrate processing on the wafer 200, which is a product substrate.

[0130] In the comparative example processing furnace, the inner surface of the top of the inner tube is flat and lacks the protrusion 204b. Furthermore, the top plate of the wafer boat is circular and lacks an opening. Furthermore, multiple dummy substrates are stacked on the wafer boat at the upper and lower ends of the wafers 200 (product substrates) in the arrangement direction. In other words, there is no cover 400 located below the wafer boat.

[0131] Figure 9 (A) is a diagram showing the partial pressure distribution of SiCl2 as a decomposition product of SiCl2 gas when SiCl2 gas is supplied to the processing furnace of the comparative example, Figure 9(B) is a diagram showing the partial pressure distribution of SiCl 2 , which is a decomposition product of SiCl 2 gas, when the SiCl 2 gas is supplied into the processing furnace 202 of this embodiment.

[0132] exist Figure 9 (A) and Figure 9 In (B), the case where SiCl2 gas is supplied from the left is shown. Figure 9 As shown in (A), in the processing furnace of the comparative example, SiCl2 gas is supplied to the wafer at a high concentration above the processing furnace (near the top). Figure 9 As shown in (B), in the processing furnace 202 of the present embodiment, it was confirmed that the concentration of the SiCl2 gas above the processing furnace 202 (near the top) was relaxed compared to the case of using the processing furnace of the comparative example, and the concentration difference of the SiCl2 gas between the wafers was relaxed, and the partial pressure distribution of SiCl2 in the arrangement direction of the wafers became the same.

[0133] Figure 10 (A) is a graph showing the inter-wafer surface uniformity of the average value of the SiCl 2 partial pressure on the wafer in each slot number. Figure 10 (B) is a graph showing wafer surface uniformity comparing values obtained by dividing the difference between the wafer center and the wafer periphery in each slot number by the average value. The larger the slot number, the higher the wafer is placed on the wafer boat 217.

[0134] like Figure 10 As shown in Figure (A), when SiN films were formed on wafers using the comparative example processing furnace, the SiCl₂ partial pressure was higher in the upper and lower layers of the wafer boat than in the middle layer. Specifically, the SiN films formed on the upper and lower layers were thicker than those formed on the middle layer. Furthermore, the difference between the maximum and minimum SiCl₂ partial pressures was 0.242.

[0135] In contrast, when SiN films were formed on wafers using the processing furnace 202 of this embodiment, the SiCl2 partial pressure in the upper layer of the wafer boat 217 was confirmed to be lower, resulting in improved variation, compared to the case using the processing furnace of the comparative example. Specifically, the thickness of the SiN film formed on the wafers in the upper layer was confirmed to be equal to the thickness of the SiN film formed on the wafers in the middle layer. Furthermore, the difference between the maximum and minimum SiCl2 partial pressures was 0.131, half the difference of 0.242 (the difference between the maximum and minimum SiCl2 partial pressures in the comparative example). This indicates improved inter-surface uniformity compared to the case using the processing furnace of the comparative example.

[0136] In addition, if Figure 10As shown in (B), when a SiN film was formed on a wafer using the processing furnace of the comparative example, it was confirmed that the in-plane uniformity in the upper and lower layers of the wafer boat was worse than that in the middle layer, and there was a deviation in the height direction of the wafer boat.

[0137] In contrast, when the SiN film was formed on the wafer using the processing furnace 202 of this embodiment, it was confirmed that the in-plane uniformity of the upper layer of the wafer boat 217 was improved compared to the case where the processing furnace of the above-mentioned comparative example was used, and the deviation in the height direction of the wafer boat 217 was improved.

[0138] In the comparative example processing furnace, residual gas remains unconsumed and accumulates between the inner surface of the top of the inner tube and the wafer boat's top plate, between the wafer boat's top plate and the dummy substrate, and between the dummy substrates. Furthermore, this unconsumed, accumulated gas intrudes into the area where the product substrates are placed. Consequently, the film thickness formed on product substrates closer to the wafer boat's top plate and the dummy substrates differs from that formed on product substrates farther from the wafer boat's top plate and the dummy substrates, due to differences in the amount of process gas supplied. This results in poor inter- and intra-plane uniformity.

[0139] In contrast, in the processing furnace 202 of this embodiment, it was confirmed that by reducing the residual gas space above the wafer boat 217, the gas volume in the residual gas space could be reduced by approximately 68% compared to the processing furnace of the comparative example. This confirmed that the SiCl2 partial pressure could be maintained constant along the wafer loading direction, improving both inter-surface and intra-surface uniformity compared to the processing furnace of the comparative example.

[0140] The above embodiment can achieve the following effects. That is, the residual gas generated on the monitoring substrate and the dummy substrate, which consume less processing gas, and in the gap between the top plate 211 of the wafer boat 217 and the inner surface of the reaction tube 203 is reduced, and the amount of residual gas intruding into the area where the product substrate is placed is reduced. Therefore, the product substrate placed in the area close to the area where the monitoring substrate and the dummy substrate are placed, and the top plate of the substrate holder, is supplied with more processing gas than the product substrate placed in the area far from the area where the monitoring substrate and the dummy substrate are placed, and the thickness of the formed film can be prevented from becoming thicker. That is, the inter-surface uniformity can be improved. The residual gas is supplied from the periphery (end side) of the wafer 200, thereby preventing the film formed at the end of the wafer 200 from becoming relatively thicker, which would lead to deterioration of the in-surface uniformity.

[0141] Furthermore, although specific embodiments of the present invention have been described in detail, the present invention is not limited to these embodiments, and it will be apparent to those skilled in the art that various other embodiments can be implemented within the scope of the present invention.

[0142] Explanation of symbols

[0143] 101—substrate processing device; 203, 503—reaction tube; 204, 304—inner tube; 204a, 304a, 503a—top; 204b, 304b, 503b—convex portion (an example of a protrusion); 204c, 304c, 503c—concave portion; 205—outer tube; 200—wafer (an example of a substrate); 201—processing chamber; 210—bottom plate; 211—top plate; 217—wafer boat (an example of a substrate holder); 400—cover.

Claims

1. A substrate processing device, characterized in that: have: a substrate holder that arranges and holds the substrate; and a reaction tube which accommodates the substrate holder therein, The substrate holder has: a plurality of pillars extending around the arranged substrates in a direction substantially perpendicular to the substrates; a top plate that fixes one end of each of the plurality of columns to each other and has an opening in the center; and a bottom plate, which fixes the other ends of the plurality of columns to each other, The reaction tube has a protruding portion with a flat front end protruding inward in a shape corresponding to the shape of the opening. The protrusion is configured to be inserted into the opening when the substrate holder is accommodated in the reaction tube and to be closer to the substrate disposed closest to the top plate of the substrate holder than to the top plate. The height of the protrusion is configured so that the interval between the protrusion and the substrate disposed closest to the top plate of the substrate holder is substantially equal to the interval between adjacent substrates on the substrate holder.

2. The substrate processing apparatus according to claim 1, wherein: The reaction tube comprises: an inner tube for housing the substrate holder; and an outer tube having a pressure-resistant structure and housing the inner tube. The inner tube further includes a top portion terminating the upper portion, and the protrusion is provided at the top portion.

3. The substrate processing apparatus according to claim 2, wherein: It also includes a nozzle extending parallel to the arrangement direction of the substrates and supplying gas to each of the arranged substrates. The inner tube further has a bulge on a side surface. The bulge is formed to bulge outward and houses the nozzle therein.

4. The substrate processing apparatus according to claim 1, wherein: It also includes a rotating shaft that rotatably supports the substrate holder. The opening and the protrusion are formed in a circular shape concentric with the rotation axis.

5. The substrate processing apparatus according to claim 1, wherein: The invention further comprises a cover that surrounds a plurality of arrangement positions of the substrates on the substrate holder, including an arrangement position closest to the bottom plate, from an upper surface and side surfaces. The substrate holder does not hold product substrates and monitoring substrates at the plurality of arrangement positions surrounded by the cover, but holds a plurality of product substrates or monitoring substrates at the plurality of arrangement positions between the cover and the top plate.

6. The substrate processing apparatus according to claim 3, wherein: The invention further comprises a cover that surrounds a plurality of arrangement positions of the substrates on the substrate holder, including an arrangement position closest to the bottom plate, from an upper surface and side surfaces. The nozzle does not have a gas supply port at positions corresponding to the plurality of arrangement positions surrounded by the cover, but has a gas supply port at positions corresponding to the plurality of product substrates or monitoring substrates held at the plurality of arrangement positions between the cover and the top plate.

7. The substrate processing apparatus according to claim 2, wherein: The inner surface of the top portion of the inner tube is entirely formed along the shape of the top plate of the substrate holder.

8. The substrate processing apparatus according to claim 1 or 4, wherein: have: a cover that closes an opening for allowing the substrate holder to enter and exit the processing container formed by the reaction tube; a rotating mechanism provided on the cover and holding the substrate holder using the reaction tube; and a sealing member for sealing between the reaction tube and the cover without directly contacting the reaction tube and the cover; The height of the protrusion is set so that when the sealing member reaches a predetermined crushing amount enabling sealing, the distance between the protrusion and the substrate disposed closest to the top plate is substantially equal to the distance between adjacent substrates in the substrate holder.

9. The substrate processing apparatus according to claim 1, wherein: have: a cover that closes an opening for allowing the substrate holder to enter and exit the processing container formed by the reaction tube; a rotating mechanism provided on the cover and holding the substrate holder using the reaction tube; and a sealing member for sealing between the reaction tube and the cover without directly contacting the reaction tube and the cover; The height of the protrusion is set so that when the sealing member reaches a predetermined crushing amount capable of sealing, the distance between the protrusion and the virtual substrate arranged closest to the top plate is sufficiently smaller than the distance between adjacent substrates in the substrate holder and is larger than the change in the predetermined crushing amount.

10. The substrate processing apparatus according to claim 5, wherein: The substrate holder holds the plurality of product substrates or monitoring substrates at a plurality of arrangement positions between the cover and the top plate, excluding the arrangement position closest to the top plate.

11. A method for manufacturing a semiconductor device, characterized in that: have: a step of accommodating a substrate holder inside a reaction tube, the substrate holder comprising: a plurality of columns for arranging and holding substrates and extending around the substrates in a direction substantially perpendicular to the substrates; a top plate for fixing one end of each of the plurality of columns to each other and having an opening at the center; and a bottom plate for fixing the other ends of each of the plurality of columns to each other, the reaction tube having a protrusion with a flat tip protruding inward in a shape corresponding to the shape of the opening; and a step of processing the substrate inside the reaction tube, In the process of being housed inside the reaction tube, The protrusion is inserted into the opening and is closer to the substrate arranged closest to the top plate of the substrate holder than the top plate. The height of the protrusion is set so that the distance between the protrusion and the substrate arranged closest to the top plate of the substrate holder is approximately equal to the distance between adjacent substrates on the substrate holder.

12. A storage medium, characterized in that: A program is stored, which causes a computer of the substrate processing apparatus to execute the following steps: The step of accommodating a substrate holder inside a reaction tube, the substrate holder comprising: a plurality of columns for arranging and holding substrates and extending around the substrates in a direction substantially perpendicular to the substrates; a top plate for fixing one end of each of the plurality of columns to each other and having an opening at the center; and a bottom plate for fixing the other ends of each of the plurality of columns to each other, the reaction tube having a protrusion with a flat front end protruding inward in a shape corresponding to the shape of the opening; and The step of processing the substrate inside the reaction tube, During the step of being housed inside the reaction tube, the following control is performed: The protrusion is inserted into the opening and is closer to the substrate arranged closest to the top plate of the substrate holder than the top plate. The height of the protrusion is set so that the distance between the protrusion and the substrate arranged closest to the top plate of the substrate holder is approximately equal to the distance between adjacent substrates on the substrate holder.

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