Substrate processing apparatus, susceptor cover, method of manufacturing semiconductor device, and substrate processing method

Abstract

The substrate processing apparatus has: a processing chamber for accommodating a substrate; and a substrate support portion provided in the processing chamber, including a susceptor for supporting the substrate and a susceptor cover disposed on the upper surface of the susceptor. In this substrate processing apparatus, the following structure is provided: the susceptor has a heating element and a first through hole provided at a position avoiding the heating element, and the susceptor cover has a second through hole that communicates with the first through hole and has a diameter larger than that of the first through hole.

Description

Technical Field

[0001] The present disclosure relates to a substrate processing apparatus, a susceptor cover, a method for manufacturing a semiconductor device, and a substrate processing method. Background Art

[0002] When forming a circuit pattern of a semiconductor device such as a flash memory, there is a case where a process of performing a predetermined process such as an oxidation process or a nitridation process on a substrate is performed as one of the manufacturing processes. For example, Patent Document 1 discloses a process of modifying the surface of a pattern formed on a substrate using a processing gas excited by plasma.

[0003] As also shown in Patent Document 1, a susceptor for placing a substrate is disposed in a processing chamber of a substrate processing apparatus. A heater is provided on the susceptor to heat the placed substrate. In addition, a through hole and a lift pin inserted through the through hole are provided on the susceptor. After the substrate processing is completed, the placed substrate is lifted by the lift pin inserted through the through hole and spaced apart from the susceptor.

[0004] In addition, as also shown in Patent Document 2, by covering the upper surface of the susceptor with a susceptor cover and placing the substrate on the susceptor cover, the heat emitted from the susceptor heated by the heater is conducted in the susceptor cover to heat the substrate. In this case, a through hole and a lift pin are also provided on the susceptor, and thus, a hole communicating with the through hole penetrates the susceptor cover.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2014-75579

[0008] Patent Document 2: Japanese Unexamined Patent Application Publication No. 2012-216774 Summary of the Invention

[0009] Since there is no susceptor cover in the portion of the hole of the susceptor cover communicating with the through hole of the susceptor, heat conduction from the susceptor cover to the substrate does not occur, and the portion of the substrate located above the portion of the hole is not sufficiently heated, and local temperature reduction may occur in the substrate surface.

[0010] An object of the present disclosure is to suppress local temperature reduction in a portion of a substrate placed on a susceptor cover and located above a portion of a hole of the susceptor cover communicating with a through hole of the susceptor, and to obtain a desired temperature distribution in the substrate surface.

[0011] According to one aspect of the present disclosure, the following technology is provided: a substrate processing apparatus having: a processing chamber for accommodating a substrate; a substrate support portion provided in the processing chamber, including a susceptor for supporting the substrate and a susceptor cover disposed on the upper surface of the susceptor. In this substrate processing apparatus, the susceptor has a heating element and a first through hole provided at a position avoiding the heating element, and the susceptor cover has a second through hole that communicates with the first through hole and has a diameter larger than that of the first through hole.

[0012] Effect of the Invention

[0013] According to the technology of the present disclosure, it is possible to suppress a local temperature drop at a portion above the portion of the substrate placed on the susceptor cover that is in communication with the through hole of the susceptor, and to obtain a desired temperature distribution within the substrate surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a schematic cross-sectional view of a substrate processing apparatus according to a first embodiment of the present disclosure.

[0015] Figure 2 is a schematic diagram illustrating the principle of plasma generation in the substrate processing apparatus according to the first embodiment of the present disclosure.

[0016] Figure 3 is a block diagram showing the configuration of a control unit (control portion) of the substrate processing apparatus according to the first embodiment of the present disclosure.

[0017] Figure 4 is a flowchart showing the substrate processing procedure according to the first embodiment of the present disclosure.

[0018] Figure 5 is a schematic diagram of a case where the first through hole and the second through hole have the same diameter.

[0019] Figure 6 is a schematic diagram showing a state where no susceptor heater exists directly below the second through hole in a case where the second through hole has a larger diameter than the first through hole.

[0020] Figure 7 is a representation of Figure 6 a plan view of a part of the susceptor and the susceptor cover.

[0021] Figure 8 is a schematic diagram showing a state where a susceptor heater exists directly below the second through hole in a case where the second through hole has a larger diameter than the first through hole.

[0022] Figure 9 is a representation of Figure 8 a plan view of a part of the susceptor and the susceptor cover.

[0023] Figure 10 It is a graph showing the thickness of the silicon oxide film of the wafer in the embodiment. Detailed implementation mode

[0024] (1) Structure of the substrate processing apparatus

[0025] The following uses Figure 1 and Figure 2 to describe the substrate processing apparatus of the embodiment of the present disclosure. The substrate processing apparatus of this embodiment is configured to mainly perform oxidation treatment on the film formed on the substrate surface.

[0026] (Processing chamber)

[0027] The substrate processing apparatus 100 includes a processing furnace 202 for performing plasma processing on the substrate 200. A processing container 203 constituting the processing chamber 201 is provided in the processing furnace 202. The processing container 203 includes a dome-shaped upper container 210 as the first container and a bowl-shaped lower container 211 as the second container. The upper container 210 covers the lower container 211 to form the processing chamber 201. The upper container 210 is formed of a material that transmits electromagnetic waves, such as a non-metallic material such as quartz (SiO2).

[0028] The lower container 211 is formed of, for example, aluminum (Al). In addition, a gate valve 244 is provided on the lower side wall of the lower container 211.

[0029] The processing chamber 201 has: a plasma generation space 201a (refer to Figure 2 ), in which an electromagnetic field generation electrode 212 composed of a resonance coil is provided around it; and a substrate processing space 201b (refer to Figure 2 ), which communicates with the plasma generation space 201a and is used to process the substrate 200. The plasma generation space 201a is a space for generating plasma, which refers to the space in the processing chamber that is above the lower end and below the upper end of the electromagnetic field generation electrode 212. On the other hand, the substrate processing space 201b is a space for processing the substrate using plasma, which refers to the space below the lower end of the electromagnetic field generation electrode 212.

[0030] (Base)

[0031] At the center of the bottom side of the processing chamber 201, a susceptor 217 serving as a substrate placement unit for placing the substrate 200 is disposed. The susceptor 217 is circular in plan view and is composed of an upper surface portion 217d and a lower surface portion 217e made of the same material, and a susceptor heater 217b interposed therebetween. The upper surface portion 217d and the lower surface portion 217e are formed of a non-metallic material such as aluminum nitride (AlN), ceramics, quartz, etc. In the present embodiment, the upper surface portion 217d and the lower surface portion 217e are formed of transparent quartz as a material through which infrared ray components of the radiant light emitted from the susceptor heater 217b described later can pass.

[0032] Inside the susceptor 217 for processing the substrate 200 in the processing chamber 201, the susceptor heater 217b serving as a heating mechanism 110 that radiates infrared rays to heat the substrate 200 housed in the processing chamber 201 is integrally buried and provided between the upper surface portion 217d and the lower surface portion 217e. Specifically, the susceptor heater 217b is inserted into a groove provided on the lower surface of the upper surface portion 217d, and is covered from the lower side of the susceptor heater 217b by the lower surface portion 217e. The susceptor heater 217b is configured to be able to heat the surface of the substrate 200 to, for example, about 25°C to 800°C when power is supplied. In addition, the susceptor heater 217b is formed of, for example, one of silicon carbide (SiC), carbon, and molybdenum, and particularly preferably formed of SiC.

[0033] The susceptor heater 217b mainly radiates light having a wavelength in the infrared region (about 0.7 to 1000 μm). In particular, in the case of the susceptor heater 217b formed of SiC, by supplying current, infrared rays having a wavelength of, for example, about 1 to 20 μm, more preferably about 1 to 15 μm are radiated. The peak wavelength of the infrared rays in this case is, for example, about 5 μm. In order to radiate a sufficient amount of infrared rays, it is desirable to heat the susceptor heater 217b to 500°C or higher, and preferably to 1000°C or higher. In addition, the expression of the numerical range such as "1 to 20 μm" in this specification means that the lower limit value and the upper limit value are included in this range. For example, "1 to 20 μm" means "1 μm or more and 20 μm or less". The same applies to other numerical ranges.

[0034] A susceptor lifting mechanism 268 is provided on the susceptor 217, and the susceptor lifting mechanism 268 includes a drive mechanism for lifting and lowering the susceptor 217. In addition, a first through hole 217a serving as a through hole that is circular in plan view is provided on the susceptor 217, and a substrate lift pin 266 is provided on the bottom surface of the lower container 211.

[0035] The upper surface of the base 217 is covered by a base cover 300. The base cover 300 is circular in a plan view and is one size smaller than the base 217, and is formed of a material different from that of the upper surface portion 217d and the lower surface portion 217e, for example, SiC. A second through hole 300a communicating with the first through hole 217a of the base 217 is provided in the base cover 300. The second through hole 300a is a through hole that is circular in a plan view, and its inner diameter is larger than the inner diameter of the first through hole 217a.

[0036] At least three of the first through hole 217a, the second through hole 300a, and the substrate lifting pin 266 are provided at positions opposite to each other. It is configured such that when the base 217 is lowered by the base lifting mechanism 268, the substrate lifting pin 266 penetrates through the first through hole 217a and the second through hole 300a.

[0037] The substrate support portion 400 of the present embodiment mainly includes a base 217 and a base cover 300.

[0038] (Processing gas supply unit)

[0039] The processing gas supply unit 120 that supplies processing gas into the processing container 203 is configured as follows.

[0040] A gas supply head 236 is provided above the processing chamber 201, that is, at the upper part of the upper container 210. The gas supply head 236 includes a lid-shaped cover body 233, a gas introduction port 234, a buffer chamber 237, an opening 238, a shielding plate 240, and a gas outlet 239, and is configured to be able to supply reaction gas into the processing chamber 201.

[0041] An oxygen-containing gas supply pipe 232a that supplies oxygen (O2 gas) as an oxygen-containing gas, a hydrogen-containing gas supply pipe 232b that supplies hydrogen (H2 gas) as a hydrogen-containing gas, and an inert gas supply pipe 232c that supplies argon (Ar gas) as an inert gas are connected to the gas introduction port 234 in a confluent manner. An O2 gas supply source 250a, an MFC (mass flow controller) 252a as a flow control device, and a valve 253a as an on-off valve are provided in the oxygen-containing gas supply pipe 232a. An H2 gas supply source 250b, an MFC 252b, and a valve 253b are provided in the hydrogen-containing gas supply pipe 232b. An Ar gas supply source 250c, an MFC 252c, and a valve 253c are provided in the inert gas supply pipe 232c. A valve 243a is provided on the downstream side of the supply pipe 232 after the oxygen-containing gas supply pipe 232a, the hydrogen-containing gas supply pipe 232b, and the inert gas supply pipe 232c are confluent, and is connected to the gas introduction port 234.

[0042] The process gas supply unit 120 (gas supply system) of this embodiment mainly consists of a gas supply head 236, an oxygen-containing gas supply pipe 232a, a hydrogen-containing gas supply pipe 232b, an inert gas supply pipe 232c, MFCs 252a, 252b, 252c, valves 253a, 253b, 253c, and 243a.

[0043] (Exhaust unit)

[0044] A gas exhaust port 235 for exhausting the ambient gas in the processing chamber 201 is provided on the side wall of the lower container 211. The upstream end of a gas exhaust pipe 231 is connected to the gas exhaust port 235. An APC (Auto Pressure Controller), which serves as a pressure regulator (pressure adjustment unit), a valve 243b serving as an on-off valve, and a vacuum pump 246 serving as a vacuum exhaust device are provided in the gas exhaust pipe 231.

[0045] The exhaust unit of this embodiment mainly consists of a gas exhaust port 235, a gas exhaust pipe 231, an APC 242, and a valve 243b. In addition, the vacuum pump 246 may be included in the exhaust unit.

[0046] (Plasma generation unit)

[0047] An electromagnetic field generation electrode 212 composed of a spiral resonance coil is provided outside the side wall of the upper container 210, which is the outer peripheral portion of the processing chamber 201, so as to surround the processing chamber 201. An RF sensor 272, a high-frequency power supply 273, and a matcher 274 for matching the impedance and output frequency of the high-frequency power supply 273 are connected to the electromagnetic field generation electrode 212. The electromagnetic field generation electrode 212 is configured to be arranged along the outer peripheral surface of the processing container 203 at an interval from the outer peripheral surface thereof, and an electromagnetic field is generated in the processing container 203 by supplying high-frequency power (RF power). That is, the electromagnetic field generation electrode 212 of this embodiment is an electrode of the Inductively Coupled Plasma (ICP) method.

[0048] The high-frequency power supply 273 is used to supply RF power to the electromagnetic field generation electrode 212. The RF sensor 272 is provided on the output side of the high-frequency power supply 273 and is used to monitor information on the traveling wave and reflected wave of the supplied high frequency. The reflected wave power monitored by the RF sensor 272 is input to the matcher 274, and the matcher 274 controls the impedance of the high-frequency power supply 273 and the frequency of the output RF power so as to minimize the reflected wave based on the information on the reflected wave input from the RF sensor 272.

[0049] The resonant coil serving as the electromagnetic field generation electrode 212 sets the coil diameter, winding pitch, and number of turns so as to resonate at a constant wavelength in order to form a standing wave of a specified wavelength. That is, the electrical length of the resonant coil is set to a length equivalent to an integer multiple of 1 wavelength at the specified frequency of the high-frequency power supplied from the high-frequency power source 273.

[0050] Both ends of the resonant coil serving as the electromagnetic field generation electrode 212 are electrically grounded, and at least one of them is grounded via the movable tap 213. The other end of the resonant coil is provided via the fixed ground wire 214. In addition, in order to finely adjust the impedance of the resonant coil, a power supply unit is constituted by the movable tap 215 between the grounded ends of the resonant coil.

[0051] The shielding plate 223 is provided to shield the electric field outside the resonant coil serving as the electromagnetic field generation electrode 212.

[0052] The plasma generation unit of the present embodiment mainly includes the electromagnetic field generation electrode 212, the RF sensor 272, and the matcher 274. In addition, as the plasma generation unit, the high-frequency power source 273 may also be included.

[0053] Here, Figure 2 the plasma generation principle of the device of the present embodiment and the properties of the generated plasma will be described.

[0054] In the plasma generation circuit constituted by the electromagnetic field generation electrode 212, when plasma is generated, due to changes in the capacitive coupling between the voltage part of the resonant coil and the plasma, changes in the inductive coupling between the plasma generation space 201a and the plasma, the excitation state of the plasma, etc., the actual resonant frequency changes slightly although it is small.

[0055] Therefore, in the present embodiment, the matcher 274 increases or decreases the impedance or output frequency of the high-frequency power source 273 based on the reflected wave power detected by the RF sensor 272 from the electromagnetic field generation electrode 212 when plasma is generated, so as to minimize the reflected wave power.

[0056] According to this configuration, in the electromagnetic field generation electrode 212 of the present embodiment, as Figure 2 shown, high-frequency power generated based on the actual resonant frequency of the resonant coil including plasma is supplied, so that a standing wave in which the phase voltage and the opposite-phase voltage always cancel each other out is formed. When the electrical length of the resonant coil serving as the electromagnetic field generation electrode 212 is the same as the wavelength of the high-frequency power, the highest phase current is generated at the neutral point (node where the voltage is zero) of the coil. Therefore, near the neutral point, there is almost no capacitive coupling between the processing chamber wall or the pedestal 217, and an annular inductive plasma with a very low electric potential is formed.

[0057] (Control Unit)

[0058] The controller 291, which serves as the control unit, is configured to control the APC 242, valve 243b, and vacuum pump 246 via signal line A, the base lifting mechanism 268 via signal line B, the heater power adjustment mechanism 276 via signal line C, the gate valve 244 via signal line D, the RF sensor 272, high-frequency power supply 273, and matcher 274 via signal line E, and the MFCs 252a - 252c, valves 253a - 253c, and 243a via signal line F.

[0059] As Figure 3 shown, the controller 291, which serves as the control unit (control unit), is configured as a computer having a CPU (Central Processing Unit) 291a, a RAM (Random Access Memory) 291b, a storage device 291c, and an I / O interface 291d. The RAM 291b, storage device 291c, and I / O interface 291d are configured to be able to exchange data with the CPU 291a via an internal bus 291e. An input / output device 292 configured as, for example, a touch panel or a display is connected to the controller 291.

[0060] The storage device 291c is composed of, for example, a flash memory, an HDD (Hard Disk Drive), etc. A control program for controlling the operation of the substrate processing device, a process recipe (formula) that describes the steps, conditions, etc. of the substrate processing described later, etc. are stored in a readable manner in the storage device 291c. The process recipe is combined in such a way that the controller 291 can execute each step in the substrate processing process described later and obtain a specified result, and functions as a program. Hereinafter, the process recipe, control program, etc. are also collectively referred to as a program for short.

[0061] The I / O interface 291d is connected to the above-mentioned MFCs 252a - 252c, valves 253a - 253c, 243a, 243b, gate valve 244, APC 242, vacuum pump 246, RF sensor 272, high-frequency power supply 273, matcher 274, base lifting mechanism 268, heater power adjustment mechanism 276, etc.

[0062] The CPU 291a is configured to read and execute a control program from the storage device 291c, and read a process from the storage device 291c based on the input of an operation instruction from the input / output device 292, etc. Further, the CPU 291a is configured to control the opening / closing adjustment operation of the APC 242, the opening / closing operation of the valve 243b, and the start / stop of the vacuum pump 246 via the I / O interface 291d and the signal line A in accordance with the content of the read process, control the lifting operation of the susceptor lifting mechanism 268 via the signal line B, control the supply power amount adjustment operation (temperature adjustment operation) to the susceptor heater 217b by the heater power adjustment mechanism 276 via the signal line C, control the opening / closing operation of the gate valve 244 via the signal line D, control the operations of the RF sensor 272, the matcher 274, and the high-frequency power supply 273 via the signal line E, and control the flow rate adjustment operations of various gases performed by the MFCs 252a to 252c, and the opening / closing operations of the valves 253a to 253c, 243a, etc. via the signal line F.

[0063] The controller 291 can be configured by installing the above program stored in the external storage device 293 on a computer. The storage device 291c and the external storage device 293 are configured as computer-readable recording media. Hereinafter, these are also collectively referred to and simply called recording media.

[0064] (2) Substrate processing process

[0065] Next, mainly using Figure 4 the substrate processing process of the present embodiment will be described. Figure 4 is a flowchart showing the substrate processing process of the present embodiment. The substrate processing process of the present embodiment is implemented by the above-described substrate processing apparatus 100 as one process of a manufacturing process (manufacturing method of semiconductor devices) of semiconductor devices such as flash memories. In the following description, the operations of the respective parts constituting the substrate processing apparatus 100 are controlled by the controller 291.

[0066] In addition, a silicon layer is previously formed on the surface of the substrate 200 to be processed in the substrate processing process of the present embodiment. In the present embodiment, an oxidation process is performed on this silicon layer as a process using plasma.

[0067] (Substrate feeding process S110)

[0068] First, the base lifting mechanism 268 lowers the base 217 to the conveyance position of the substrate 200, causing the substrate lift pins 266 to pass through the first through-hole 217a of the base 217 and the second through-hole 300a of the base cover 300. Next, the gate valve 244 is opened, and the substrate 200 is fed into the processing chamber 201 from the vacuum conveyance chamber adjacent to the processing chamber 201 using a substrate conveyance mechanism (not shown). The fed substrate 200 is supported in a horizontal posture on the substrate lift pins 266 protruding from the surface of the base cover 300. Then, the base lifting mechanism 268 raises the base 217, so that the substrate 200 is supported on the upper surface of the base cover 300.

[0069] (Heating and Vacuum Exhausting Process S120)

[0070] Next, the substrate 200 fed into the processing chamber 201 is heated. Here, the base heater 217b is preheated to a specified value within a range of, for example, 500 to 1000°C, and the substrate 200 held on the base 217 is heated to a specified temperature using the heat generated from the base heater 217b. Among them, the substrate 200 is heated so that its temperature becomes, for example, 700°C. In addition, during the heating of the substrate 200, the inside of the processing chamber 201 is vacuum-exhausted using the vacuum pump 246 via the gas exhaust pipe 231, and the pressure inside the processing chamber 201 is set to a specified value. The vacuum pump 246 is operated at least until the end of the substrate delivery process S160 described later.

[0071] (Reactive Gas Supply Process S130)

[0072] Next, as the reactive gases, the supply of O2 gas as an oxygen-containing gas and H2 gas as a hydrogen-containing gas is started. Specifically, valves 253a and 253b are opened, and the supply of O2 gas and H2 gas into the processing chamber 201 is started while controlling the flow rates using the MFCs 252a and 252b.

[0073] In addition, the opening degree of the APC 242 is adjusted to control the exhaust inside the processing chamber 201 so that the pressure inside the processing chamber 201 becomes a specified value. In this way, the inside of the processing chamber 201 is moderately exhausted, and the supply of O2 gas and H2 gas is continued until the end of the plasma processing process S140 described later.

[0074] (Plasma Processing Process S140)

[0075] After the pressure in the processing chamber 201 stabilizes, high-frequency power is applied from the high-frequency power supply 273 to the electromagnetic field generating electrode 212. As a result, a high-frequency electric field is formed in the plasma generation space 201a supplied with O2 gas and H2 gas. Through this electric field, a ring-shaped inductive plasma with the highest plasma density is excited at a height position corresponding to the neutral point of the electromagnetic field generating electrode 212 in the plasma generation space. The processing gas containing plasma-like O2 gas and H2 gas is excited by the plasma and dissociates to generate reactive species such as oxygen radicals (oxygen active species) containing oxygen, oxygen ions, hydrogen radicals (hydrogen active species) containing hydrogen, and hydrogen ions.

[0076] For the substrate 200 held on the susceptor 217 in the substrate processing space 201b, radicals generated by inductive plasma and ions in an unaccelerated state are uniformly supplied to the surface of the substrate 200. The supplied radicals and ions react uniformly with the silicon layer on the surface, modifying the silicon layer into a silicon oxide layer with good step coverage.

[0077] After that, after a predetermined processing time, for example, 10 to 1000 seconds, the output of power from the high-frequency power supply 273 is stopped to stop the plasma discharge in the processing chamber 201. In addition, the valves 253a and 253b are closed to stop the supply of O2 gas and H2 gas into the processing chamber 201. Through the above steps, the plasma processing step S140 ends.

[0078] (Vacuum evacuation step S150)

[0079] After stopping the supply of O2 gas and H2 gas, the inside of the processing chamber 201 is evacuated through the gas exhaust pipe 231. As a result, the gas inside the processing chamber 201 is discharged to the outside of the processing chamber 201. After that, the opening degree of the APC 242 is adjusted to adjust the pressure inside the processing chamber 201 to the same pressure as that of the vacuum transfer chamber adjacent to the processing chamber 201.

[0080] (Substrate delivery step S160)

[0081] After the pressure inside the processing chamber 201 reaches a predetermined value, the susceptor 217 is lowered to the substrate delivery position, and the substrate 200 is supported on the substrate lift pins 266. Then, the gate valve 244 is opened, and the substrate 200 is delivered out of the processing chamber 201 using the substrate transfer mechanism. Through the above steps, the substrate processing step of the present embodiment ends.

[0082] <Susceptor cover>

[0083] As described above, the substrate processing apparatus 100 according to an embodiment of the present disclosure includes: a processing chamber 201 for accommodating a substrate 200; and a substrate support portion 400 disposed in the processing chamber 201 and including a susceptor 217 for supporting the substrate 200 and a susceptor cover 300 disposed on the upper surface of the susceptor 217. The susceptor 217 is a heating element for heating the substrate 200, and includes a susceptor heater 217b formed of a heating wire and a plurality of first through-holes 217a serving as through-holes provided at positions avoiding the susceptor heater 217b. The susceptor cover 300 has a plurality of second through-holes 300a that communicate with the first through-holes 217a and have a diameter larger than that of the first through-holes 217a.

[0084] In other words, in the substrate processing apparatus 100 having the processing chamber 201 for accommodating the substrate 200, the susceptor cover 300 is disposed on the upper surface of the susceptor 217 that supports the substrate 200 and is included in the substrate support portion 400 disposed in the processing chamber 201. Further, the susceptor cover 300 has a plurality of second through-holes 300a that communicate with the first through-holes 217a of the susceptor 217 having the susceptor heater 217b as a heating element for heating the substrate 200 and a plurality of first through-holes 217a serving as through-holes provided at positions avoiding the susceptor heater 217b, and have a diameter larger than that of the first through-holes 217a.

[0085] Here, when the diameter of the first through-hole 217a is the same as the diameter of the second through-hole 300a as shown Figure 5 below, the radiant light (hereinafter referred to as "direct radiant light"; indicated by solid arrows in the figure) generated from the susceptor heater 217b is not transferred as heat in a radiative manner to the portion of the substrate 200 directly above the second through-hole 300a (portion A surrounded by a dashed line in the figure). Further, the radiant light (hereinafter referred to as "indirect radiant light") from the susceptor 217 heated by the susceptor heater 217b is not transferred as heat in a radiative manner to the portion A either. Therefore, the portion A is less heated than other portions, and local temperature reduction may occur in the plane of the substrate 200. As a result, when performing, for example, a film forming process, the film thickness formed on the upper surface of the portion A becomes locally smaller, and the uniformity of the processing in the plane of the substrate 200 may decrease.

[0086] On the other hand, as Figure 1As shown, the diameter of the second through-hole 300a is larger than that of the first through-hole 217a. Therefore, a part of the surface of the base 217 is exposed upward from the second through-hole 300a. The radiant light from the base 217 reaches the part of the substrate 200 directly above the second through-hole 300a from this exposed part, and thus this part is also sufficiently heated by radiation. That is, when the first through-hole 217a and the second through-hole 300a need to be provided in the base 217 and the base cover 300 respectively due to the arrangement of the substrate lift pins 266 or the like, it is possible to suppress the local temperature decrease around the second through-hole 300a in the plane of the substrate 200 to be heated, and adjust the temperature distribution in the plane of the substrate 200. In particular, the in-plane temperature uniformity of the substrate 200 can be improved.

[0087] More specifically, by setting the diameters of the first through-hole 217a and the second through-hole 300a such that at least one of the direct radiant light radiated from the heated base heater 217b and the indirect radiant light radiated from the base 217 directly irradiates the substrate 200, it is possible to suppress the decrease in the in-plane temperature of the substrate 200 around the second through-hole 300a.

[0088] In addition, by changing the shape of the base cover 300 (especially the diameter of the second through-hole 300a), without changing the arrangement pattern of the base heater 217b in the base 217, it is possible to adjust the uniformity of the in-plane temperature distribution. In other words, even when using the same base 217, by changing the shape of the base cover 300, it is possible to adjust the uniformity of the in-plane temperature distribution.

[0089] Here, in the present embodiment, the base 217, the first through-hole 217a, and the second through-hole 300a are arranged such that the radiant light from the base 217 heated by the heated base heater 217b, that is, the indirect radiant light, irradiates the substrate 200 via the second through-hole 300a.

[0090] That is, as Figure 6 and Figure 7As shown, when the diameter of the second through-hole 300a is larger than that of the first through-hole 217a, even when there is no base heater 217b directly below the second through-hole 300a, the indirect radiation light (represented by the dashed arrow in the figure) from the base 217 heated by the base heater 217b reaches the portion A of the substrate 200 directly above the second through-hole 300a, and thus this portion A is sufficiently heated. In addition, when the direct radiation light emitted from the base heater 217b is incident obliquely on the surface (interface) of the base 217 exposed from the second through-hole 300a, sometimes a part of this direct radiation light is not reflected, passes through the second through-hole 300a and reaches the portion A, thereby contributing to heating. The smaller the distance between the second through-hole 300a and the base heater 217b when viewed from above, the larger the amount of such direct radiation light; the larger this distance, the smaller the amount of such direct radiation light. In particular, if this distance becomes large and the incident angle on the surface (interface) of the base 217 exposed from the second through-hole 300a exceeds the critical angle, such direct radiation light does not substantially reach the portion A and does not contribute to heating.

[0091] Here, as Figure 7 shown, the base heater 217b is formed in a pattern that avoids the first through-hole 217a in order to ensure the space for providing the substrate lift pin 266 to move up and down through the first through-hole 217a. In addition, in Figure 7 the example shown, in particular, the base heater 217b is configured to fold back near the area while avoiding the area directly below the second through-hole 300a. According to this structure, the direct radiation light from the base heater 217b does not irradiate the substrate 200 directly but irradiates the substrate 200 indirectly, thereby being able to suppress local overheating.

[0092] In addition, in the present embodiment, the base heater 217b and the second through-hole 300a may also be arranged such that the direct radiation light from the heated base heater 217b, that is, the direct radiation light, irradiates the substrate 200 through the second through-hole 300a.

[0093] That is, as Figure 8 and Figure 9 shown, when the diameter of the second through-hole 300a is larger than that of the first through-hole 217a and there is a base heater 217b directly below the second through-hole 300a, in addition to the indirect radiation light (represented by the dashed arrow in the figure) from the base 217 heated by the base heater 217b, the direct radiation light from the base heater 217b (represented by the straight arrow in the figure) also reaches the portion A of the substrate 200 directly above the second through-hole 300a, and thus this portion A is sufficiently heated.

[0094] Here, as shown in Figure 9 , the base heater 217b is arranged so that at least a part thereof overlaps with the area vertically below the second through-hole 300a. According to this structure, the direct radiation light from the base heater 217b irradiates the substrate 200, and thus, the local heating based on radiation can be promoted. In addition, as shown in Figure 9 , the base heater 217b has a concave curved portion 217c formed on the outer side of its fold-back so as to surround the first through-hole 217a, and the concave curved portion 217c is arranged so as to overlap with the area vertically below the second through-hole 300a.

[0095] In addition, the substrate processing apparatus 100 of the present embodiment further includes a substrate lifting mechanism for lifting and lowering the substrate 200 above the substrate support portion 400, and the first through-hole 217a and the second through-hole 300a are formed in such a manner that the substrate lift pins 266 constituting the substrate lifting mechanism can penetrate through the inside of the first through-hole 217a and the second through-hole 300a and move up and down.

[0096] That is, the substrate lifting mechanism is composed of a base lifting mechanism 268 and substrate lift pins 266. As the base 217 moves up and down based on the base lifting mechanism 268, the substrate 200 is relatively lifted and lowered with respect to the base 217 by the substrate lift pins 266 passing through the first through-hole 217a and the second through-hole 300a. In the case of using such a substrate lifting mechanism, holes for allowing the substrate lift pins 266 to penetrate need to be provided in the base 217 and the base cover 300. By forming the first through-hole 217a and the second through-hole 300a as in the present embodiment, the local reduction in the in-plane temperature of the substrate 200 caused by these through-holes can be alleviated, and a desired in-plane temperature distribution can be obtained. In addition, in the present embodiment, the first through-hole 217a and the second through-hole 300a are arranged with the same axis.

[0097] In addition, in the substrate processing apparatus 100 of the present embodiment, as shown in Figure 7 and Figure 9 , the upper surface of the base 217 is exposed through the second through-hole 300a in a plan view. According to this structure, the indirect radiation light radiated from the exposed upper surface of the base 217 can irradiate the substrate 200 through the second through-hole 300a.

[0098] Here, as shown in Figure 1 , Figure 6 and Figure 8As shown, the base heater 217b is disposed inside the base 217 composed of two members. Therefore, the substrate 200 is heated by heat conduction and heat radiation through the base 217. In addition, the base heater 217b may be disposed in contact with the lower surface of the base 217 composed of one member. In this case, the substrate 200 is also heated by heat conduction and heat radiation through the base 217. In either case, the base heater 217b is disposed at a position where the direct radiation light emitted from the base heater 217b irradiates at least one of the base cover 300 and the substrate 200 through the base 217.

[0099] In the present embodiment, the material of the base 217 is different from the material of the base cover 300. When the base 217 is composed of two members, an upper surface portion 217d and a lower surface portion 217e, at least the material of the upper surface portion 217d is different from the material of the base cover 300. Additionally, it is desirable that the material of the base cover 300 is a material that shields both the indirect radiation light, which is the radiation light from the base 217 heated by the base heater 217b after heating, and the direct radiation light, which is the radiation light from the heated base heater 217b. Here, the shielding of the indirect radiation light and the direct radiation light means that both substantially block the heating by the direct radiation from the base heater 217b and the indirect radiation from the heated base 217. Thus, the heating of the substrate 200 by the direct radiation light and the indirect radiation light emitted from the base heater 217b and the base 217 is only generated by the radiation through the second through hole 300a. "Substantially" means that a trace amount of indirect radiation light and direct radiation light that do not cause heating to the extent required for substrate formation is allowed to pass through.

[0100] Specifically, for the wavelength of the radiation light emitted from the base heater 217b that passes through the material of the base 217, the transmittance of the material of the base cover 300 is lower than that of the material of the base 217. Additionally, it is desirable that the thermal conductivity coefficient of the material of the base cover 300 is higher than that of the material of the base 217. In the present embodiment, the material of the base 217 is transparent quartz, and the material of the base cover 300 is SiC.

[0101] The diameter of the second through hole 300a is set to a size such that the in-plane temperature distribution of the substrate 200 becomes a desired distribution. Alternatively, the diameter of the second through hole 300a is set to a size that makes the in-plane temperature distribution of the substrate 200 the most uniform. Alternatively, the diameter of the second through hole 300a is set according to the amount of direct radiation light emitted from the susceptor heater 217b. Alternatively, the diameter of the second through hole 300a is set according to the temperature of the susceptor heater 217b during the processing of the substrate 200. The reason is that the amount and spectrum of the direct radiation light change according to the temperature of the susceptor heater 217b. Alternatively, the diameter of the second through hole 300a is set according to the characteristics (spectrum) of the wavelength of the light absorbed by the substrate 200.

[0102] <Other Embodiments of the Present Disclosure>

[0103] In the above-described embodiment, examples of the oxidation treatment and nitridation treatment of the substrate surface using plasma are illustrated. However, the present disclosure technology is not limited to these treatments and can be applied to a technology for performing heat treatment on a substrate placed on a substrate support portion having a susceptor and a susceptor cover. For example, it can be applied to a film formation treatment for forming a film on the substrate surface, a modification treatment for a film formed on the substrate surface, a doping treatment, a reduction treatment of an oxide film, an etching treatment for the film, an ashing treatment of a resist, and the like.

[0104] Examples

[0105] In the example, a susceptor cover 300 made of SiC having a circular shape (diameter 316 mm) in plan view was used, and three second through holes 300a were equally arranged near the edge. In addition, in the susceptor cover 300 of the example, the diameters of the second through holes 300a were set to 12 mm, 15 mm, and 20 mm.

[0106] In the processing chamber 201 described in the above embodiment, the susceptor cover 300 was fixedly mounted on the upper surface of the susceptor 217 having three first through holes 217a with a diameter of 6.5 mm equally arranged at corresponding positions such that the axis of the second through hole 300a coincides with the axis of the first through hole 217a. The susceptor 217 used a member in which an upper surface portion 217d and a lower surface portion 217e made of transparent quartz sandwich a susceptor heater 217b made of SiC. A single crystal silicon wafer with a diameter of 300 mm and a thickness of 1 mm was placed on the susceptor cover 300 as the substrate 200. In this state, a silicon oxide film (SiO2 film) was formed on the wafer under the following oxidation conditions.

[0107] "Wafer temperature: 700 °C

[0108] "Processing gas flow rate: O2 / H2 = 1900 sccm / 100 sccm

[0109] 〃Processing chamber pressure: 150 Pa

[0110] 〃Processing time: 600 seconds

[0111] After the treatment under the above oxidation conditions, the thickness of the SiO2 film formed on the wafer was measured for each part in the plane of the wafer surface. Here, the higher the temperature, the greater the increase in the thickness of the SiO2 film on the wafer. Therefore, it means that the thicker the SiO2 film, the higher the temperature reached at that part.

[0112] The thickness of the SiO2 film of the wafer in the examples is shown in Figure 10 the chart. Among them, the vertical axis of the chart represents the thickness of the SiO2 film (unit: ). In addition, the horizontal axis of the chart represents the measurement points for one week starting from near a certain second through-hole 300a, passing through the other two second through-holes 300a in the circumferential direction, and returning to near the original second through-hole 300a. In this chart, the three points indicated by arrows respectively correspond to the centers of the second through-holes 300a. In this chart, the point indicated by the left arrow corresponds to the center of the second through-hole 300a with a diameter of 15 mm, the point indicated by the middle arrow corresponds to the center of the second through-hole 300a with a diameter of 20 mm, and the point indicated by the right arrow corresponds to the center of the second through-hole 300a with a diameter of 12 mm.

[0113] Here, in this Figure 10 chart, assuming that the temperature of the part corresponding to each second through-hole 300a in the wafer serving as the substrate 200 is lower than its surroundings, a minimum value appears at these points. However, according to the chart of this Figure 10 in the examples, it can be seen that the thickness of the SiO2 film corresponding to each second through-hole 300a does not show a minimum value. That is, it can be seen that local temperature reduction does not occur at the parts corresponding to each second through-hole 300a in the examples. Specifically, it can be seen that the thickness of the SiO2 film corresponding to the position of the second through-hole 300a with a diameter of 12 mm is of the same magnitude as the film thickness of the surrounding positions. In addition, it can be seen that the thicknesses of the SiO2 films corresponding to the positions of the second through-holes 300a with diameters of 15 mm and 20 mm both show a maximum value relative to the film thickness of the surrounding positions. That is, it can be seen that in the wafer serving as the substrate 200, the SiO2 film is formed with the same thickness or a greater thickness compared to its surroundings at the parts corresponding to the second through-holes 300a. It was thus confirmed that by making the diameter of the second through-hole 300a larger than the diameter of the first through-hole 217a, the effect of increasing the temperature at the corresponding part and alleviating local temperature reduction was obtained.

[0114] In addition, it can also be seen from the figure that, in particular, the larger the diameter of the second through hole 300a, the higher the temperature of the corresponding part of the wafer of the substrate 200. That is, it is confirmed that adjustment can be made in such a way that the temperature of the corresponding part is increased by enlarging the diameter of the second through hole 300a.

[0115] In the case of the present embodiment, when the diameters of the second through holes 300a are 15 mm and 20 mm, the results that the temperatures of the corresponding parts are locally higher than the temperatures of the peripheral positions are significant. Therefore, it is speculated that, from the viewpoint of improving the temperature uniformity in the plane of the substrate 200, it is appropriate that the diameter of the second through hole 300a is in the range of about 1.5 times or more (i.e., in the case of a diameter of 12 mm) and less than about 2 times (i.e., in the case of a diameter of 15 mm) with respect to the diameter of the first through hole 217a.

[0116] Industrial Applicability

[0117] According to the technology of the present disclosure, it is possible to suppress a local temperature drop at a portion above a portion of a hole of a base cover that communicates with a through hole of a base in a substrate placed on the base cover, and to obtain a desired temperature distribution in the plane of the substrate.

Claims

1. A substrate processing apparatus, comprising: A processing chamber for accommodating a substrate; A substrate support portion disposed in the processing chamber, having a base for supporting the substrate and a base cover disposed on the upper surface of the base; and A substrate lift pin capable of supporting the substrate from the back above the substrate support portion, In this substrate processing apparatus, The base has a heating element and a first through hole provided at a position avoiding the heating element, The base cover has a second through hole that communicates with the first through hole and has a diameter larger than that of the first through hole, The substrate lift pin is formed such that the diameter of the upper end is smaller than the diameter of the first through hole, and the upper end can pass through the inside of the first through hole and the second through hole.

2. The substrate processing apparatus according to claim 1, wherein The first through hole and the second through hole are arranged such that indirect radiation light, which is radiation light from the base heated by the heating element, irradiates the substrate through the second through hole.

3. The substrate processing apparatus according to claim 1, wherein The heating element and the second through hole are arranged such that direct radiation light, which is radiation light from the heating element, irradiates the substrate through the second through hole.

4. The substrate processing apparatus according to any one of claims 1 to 3, wherein The upper surface of the base facing the second through hole is exposed at the opening of the second through hole in the upper surface of the base cover.

5. The substrate processing apparatus according to claim 4, wherein The substrate lift pin constitutes a substrate lifting mechanism that relatively lifts and lowers the substrate above the substrate support portion with respect to the substrate support portion.

6. The substrate processing apparatus according to claim 5, wherein The substrate lifting mechanism further includes a drive mechanism for lifting and lowering the base.

7. The substrate processing apparatus according to claim 6, wherein The substrate lifting mechanism is configured to be able to position the upper end of the lift pin at a position lower than the upper surface of the base.

8. The substrate processing apparatus according to claim 6, wherein The substrate lifting mechanism is configured to be able to position the upper end of the lift pin at a position lower than the lower surface of the base.

9. The substrate processing apparatus according to claim 7, wherein The first through hole and the second through hole are arranged such that, in a state where the upper end of the lift pin is at a position lower than the upper surface of the base, indirect radiation light, which is radiation light from the base heated by the heating element, irradiates the substrate through the second through hole.

10. The substrate processing apparatus according to claim 8, wherein The heating element and the second through hole are arranged such that, in a state where the upper end of the lift pin is at a position lower than the lower surface of the base, direct radiation light, which is radiation light from the heating element, irradiates the substrate through the second through hole.

11. The substrate processing apparatus according to claim 2, wherein The heat generating element is arranged so as to avoid a region vertically below the second through hole.

12. The substrate processing apparatus according to claim 3, wherein: The heat generating element is disposed so that at least a portion thereof overlaps with a region vertically below the second through hole.

13. The substrate processing apparatus according to claim 1, wherein: The base is made of a material that allows the radiated light from the heating element, ie, the direct radiated light, to pass therethrough.

14. The substrate processing apparatus according to claim 1, wherein: The base cover is made of a material that shields both the indirect radiation light, which is the radiation light from the base heated by the heating element, and the direct radiation light, which is the radiation light from the heating element.

15. The substrate processing apparatus according to claim 1, wherein: The diameter of the opening in the upper surface of the base cover and the diameter of the opening of the second through hole in the lower surface facing the base are larger than the diameter of the first through hole in the upper surface of the base.

16. The substrate processing apparatus according to claim 1, wherein: The diameter of the opening of the second through hole in the lower surface facing the base is the same as the diameter of the opening of the second through hole in the upper surface of the base cover.

17. A susceptor cover, in a substrate processing apparatus having a processing chamber for accommodating a substrate, arranged on an upper surface of a susceptor for supporting the substrate provided in a substrate supporting portion disposed in the processing chamber, wherein: The base cover is arranged on the upper surface of the base having a heating element and a first through hole provided at a position avoiding the heating element. The base cover has a second through hole, the second through hole communicates with the first through hole and has a diameter larger than that of the first through hole. The second through hole is formed so that a substrate lifting pin can pass through the inside of the second through hole, wherein the diameter of the upper end of the substrate lifting pin is smaller than the diameter of the first through hole and the upper end can pass through the first through hole.

18. A method for manufacturing a semiconductor device, which is a method for manufacturing a semiconductor device using a substrate processing device, the substrate processing device comprising: a processing chamber for accommodating a substrate; a substrate support portion, which is arranged in the processing chamber and has a base for supporting the substrate and a base cover arranged on the upper surface of the base; and a substrate lifting pin, which can support the substrate from the back side above the substrate supporting portion, and the base has a heating element and a first through hole arranged at a position avoiding the heating element, the base cover has a second through hole, the second through hole is connected to the first through hole and has a diameter larger than the diameter of the first through hole, the substrate lifting pin is formed so that the diameter of the upper end is smaller than the diameter of the first through hole, and the upper end can pass through the inner side of the first through hole and the second through hole, The method for manufacturing the semiconductor device comprises the following steps: The step of placing the substrate on the base cover; a step of supplying electric power to the heating element; and A step of heating the substrate using heat generated from the heating element.

19. A substrate processing method, which is a substrate processing method using a substrate processing apparatus. The substrate processing apparatus includes: a processing chamber for accommodating a substrate; a substrate support portion disposed in the processing chamber, having a susceptor for supporting the substrate and a susceptor cover disposed on the upper surface of the susceptor; and a substrate lift pin capable of supporting the substrate from the back above the substrate support portion. The susceptor has a heating element and a first through hole provided at a position avoiding the heating element. The susceptor cover has a second through hole that communicates with the first through hole and has a diameter larger than that of the first through hole. The upper surface of the susceptor facing the second through hole is exposed at the opening of the second through hole in the upper surface of the susceptor cover. The substrate lift pin is formed such that the diameter of the upper end is smaller than the diameter of the first through hole, and the upper end can pass through the inside of the first through hole and the second through hole. This substrate processing method includes the following steps: A step of placing the substrate on the susceptor cover; A step of supplying power to the heating element; and A step of heating the substrate using the heat generated from the heating element.

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