Substrate processing apparatus, substrate stage cover, processing method, semiconductor device manufacturing method, and recording medium

Abstract

A substrate processing apparatus comprises: a processing chamber for accommodating a substrate; a substrate stage disposed in the processing chamber and heated by a heater; and a substrate stage cover disposed on an upper surface of the substrate stage for mounting the substrate on the upper surface, the substrate stage cover being made of silicon carbide and having a silicon oxide layer of a predetermined first thickness on at least one surface on which the substrate is mounted.

Description

Technical Field

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

[0002] When forming circuit patterns for semiconductor devices such as flash memory, a substrate may be subjected to a predetermined treatment such as oxidation or nitridation as part of the manufacturing process. For example, Japanese Patent Application Publication Nos. 2014-75579 and 2012-216774 disclose modifying the surface of a pattern formed on a substrate using a plasma-excited processing gas. Summary of the Invention

[0003] Problems to be solved by the invention

[0004] In processing chambers used for substrate processing, a substrate stage cover is sometimes placed above the substrate stage, and substrates are placed on its upper surface for processing. However, with prolonged use of the equipment during substrate processing, an oxide layer may form not only on the substrates being processed, but also on the surfaces of components within the processing chamber, such as the substrate stage cover, due to diffusion reactions. The formation of this oxide layer on the surface of these components changes their surface emissivity, thus affecting the results of substrate processing.

[0005] An object of the present disclosure is to suppress variations in substrate processing results caused by surface oxidation of components within a processing chamber during operation of a substrate processing apparatus.

[0006] Means for solving problems

[0007] According to the present disclosure, the following technology can be provided, comprising: a processing chamber for accommodating a substrate; a substrate stage disposed within the processing chamber and heated by a heater; and a substrate stage cover configured to be disposed on an upper surface of the substrate stage and to support the substrate on the upper surface, the substrate stage cover being made of silicon carbide and having a silicon oxide layer of a predetermined first thickness on at least one surface on which the substrate is supported.

[0008] Effects of the Invention

[0009] According to the technology disclosed in the present disclosure, it is possible to suppress variations in substrate processing results caused by surface oxidation of components within a processing chamber accompanying operation of a substrate processing apparatus. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] [ Figure 1 ]A schematic cross-sectional view of a substrate processing apparatus according to this embodiment.

[0011] [ Figure 2 ]A block diagram showing the structure of the control unit (control means) of the substrate processing apparatus of this embodiment.

[0012] [ Figure 3 ] shows a flow chart of the substrate processing steps of this embodiment.

[0013] [ Figure 4 ] is a schematic diagram showing a state in which a susceptor cover is placed on a susceptor and a substrate is placed on the susceptor cover.

[0014] [ Figure 5 ] shows an oblique view of the support cover.

[0015] [ Figure 6 ] shows an enlarged cross-sectional view of a portion of the susceptor cover.

[0016] [ Figure 7 ] schematically shows an enlarged cross-sectional view of a susceptor cover in which Si oxide layers are formed on the upper and lower surface sides.

[0017] [ Figure 8 ] is a line graph showing the relationship between the oxidation treatment time and the oxide film thickness of SiC. DETAILED DESCRIPTION

[0018] (1) Structure of substrate processing apparatus

[0019] The substrate processing apparatus according to the embodiment of the present disclosure uses Figure 1 、 Figure 2 and Figure 4 The following is an explanation. It should be noted that the drawings used in the following description are schematic, and the dimensional relationships and ratios of the elements shown in the drawings are not necessarily consistent with reality. In addition, the dimensional relationships and ratios of the elements are not necessarily consistent across multiple drawings.

[0020] The substrate processing apparatus 100 of this embodiment is configured to mainly perform oxidation processing on a film formed on a substrate surface. The substrate processing apparatus 100 includes a processing chamber 201, a susceptor 217 as an example of a substrate stage, and a susceptor cover 300 as an example of a substrate stage cover.

[0021] (Processing Room)

[0022] The substrate processing apparatus 100 includes a processing furnace 202 for plasma processing a substrate 200. A processing container 203 constituting a processing chamber 201 is provided in the processing furnace 202. The processing chamber 201 accommodates the substrate 200. The processing container 203 includes a first container, i.e., a dome-shaped upper container 210, and a second container, i.e., a bowl-shaped lower container 211. The processing chamber 201 is formed by placing the upper container 210 over the lower container 211. The upper container 210 is formed of a material that transmits electromagnetic waves, such as a non-metallic material such as quartz (SiO2). The lower container 211 is formed of a metal material. In addition, a gate valve 244 is provided on the lower side wall of the lower container 211.

[0023] The processing chamber 201 comprises a plasma generation space, which is surrounded by an electromagnetic field generating electrode 212 formed of a resonant coil, and a substrate processing space connected to the plasma generation space 201a, in which the substrate 200 is processed. The plasma generation space 201a is the space within the processing chamber where plasma is generated, and is located above the lower end of the electromagnetic field generating electrode 212 and below the upper end of the electromagnetic field generating electrode 212. Meanwhile, the substrate processing space 201b is the space below the lower end of the electromagnetic field generating electrode 212 where the substrate is processed using plasma.

[0024] (Support)

[0025] The susceptor 217 is arranged in the processing chamber 201, supports the substrate 200, and is heated by a susceptor heater 217b as an example of a heater. In addition, the susceptor 217 can also be heated by an upper heater 280 as an example of a heater. The upper heater 280 is arranged above the processing chamber 201. A susceptor 217 serving as a substrate supporting portion for supporting the substrate 200 is arranged in the center of the bottom side of the processing chamber 201. The susceptor 217 is circular when viewed from above, and is composed of an upper surface portion 217d and a lower surface portion 217e of the same material, and a susceptor heater 217b interposed therebetween. The upper surface portion 217d and the lower surface portion 217e of the susceptor 217 are made of non-metallic materials such as aluminum nitride (AlN), ceramics, quartz, etc.

[0026] A susceptor heater 217b serving as a heating mechanism 110 is provided inside the susceptor 217 for processing the substrate 200 in the processing chamber 201. The heater 217b is configured to radiate infrared rays for heating the substrate 200 housed in the processing chamber 201 and is integrally embedded 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 with the lower surface portion 217e. The susceptor heater 217b is configured to heat the surface of the substrate 200 (for example, from 25°C to about 800°C) when power is supplied. It should be noted that the susceptor heater 217b is composed of, for example, silicon carbide (SiC), carbon, molybdenum, etc.

[0027] The susceptor heater 217b mainly radiates light having a wavelength in the infrared region (about 0.7 to 1000 μm). As an example, in the case of a susceptor heater 217b composed of SiC, infrared rays having a wavelength of, for example, about 1 to 20 μm, more preferably about 1 to 15 μm, are radiated by supplying current. The peak wavelength of the infrared rays in this case is, for example, around 5 μm. In order to radiate a sufficient amount of infrared rays, the susceptor heater 217b is preferably heated to above 500°C, preferably above 1000°C. It should be noted that the numerical range notation such as "1 to 20 μm" in this specification means that the lower limit and upper limit are included in the range. For example, "1 to 20 μm" means "above 1 μm and below 20 μm". The same applies to other numerical ranges.

[0028] The susceptor 217 is provided with a susceptor lifting mechanism 268 having a driving mechanism for lifting the susceptor 217. The susceptor 217 is provided with a first through hole 217a which is a circular through hole in plan view, and a substrate push pin 266 is provided on the bottom surface of the lower container 211.

[0029] (Support cover)

[0030] The upper surface of the susceptor 217 is covered with a susceptor cover 300. The susceptor cover 300, viewed from above, is circular and slightly smaller than the susceptor 217. It is made of a material different from that of the upper surface portion 217d and the lower surface portion 217e of the susceptor 217, such as SiC. SiC has high thermal conductivity and few impurities, making it a suitable material for the susceptor cover 300, which contacts the substrate 200 and can conduct heat from the susceptor heater 217b. The susceptor cover 300 is provided with a second through-hole 300a, which is circular in shape when viewed from above and communicates with the first through-hole 217a of the susceptor 217. It should be noted that, considering factors such as uniformity of heat conduction, it is preferable that the entire susceptor cover 300 be made of SiC.

[0031] At least three positions are provided at positions facing each other, the first through hole 217a, the second through hole 300a, and the substrate push pin 266. When the susceptor 217 is lowered by the susceptor lifting mechanism 268, the substrate push pin 266 is configured to pass through the first through hole 217a and the second through hole 300a.

[0032] The susceptor cover 300 is a separate body from the susceptor 217 and can be detachably mounted on the susceptor 217 .

[0033] When performing, for example, an oxidation treatment on a substrate, long-term use of the apparatus will gradually form a silicon oxide layer (SiO2 layer) not only on the surface of the substrate being processed but also on the surface of the SiC forming the susceptor cover 300. This is due to the Si element forming the SiC combining with the O element contained in the atmosphere within the processing chamber 201, resulting in a diffusion reaction and the gradual formation of a silicon oxide layer (SiO2 layer) on the surface of the susceptor cover 300. The SiO2 layer has a higher emissivity than SiC, and this emissivity increases as the thickness of the oxide layer formed on the SiC surface increases. As a result, the temperature of the substrate, which is radiated by heat from the surface of the susceptor cover 300, increases as the thickness of the oxide layer increases, and the processing throughput, such as the thickness of the film formed on the substrate 200, tends to increase. In other words, the processing results of the substrate may fluctuate over time as the apparatus is used. To reduce such fluctuations in processing results, measures such as setting the heater temperature higher at the beginning of operation and then gradually lowering the heater set temperature over the course of operation to maintain a consistent processing result (for example, to maintain a consistent film thickness obtained through processing) are necessary. Furthermore, in order to restore the susceptor cover 300 to the initial state of operation, the susceptor cover 300 needs to be replaced with a new one, which may incur replacement costs.

[0034] In this embodiment, the susceptor cover 300 is arranged on the upper surface of the susceptor 217 and has a silicon oxide layer (Si oxide layer, SiO2 layer) 300b (a layer having a first thickness T1) on at least the surface (upper surface) on the side where the substrate 200 is mounted. Figure 7 ). It should be noted that Figure 7 The layer thickness in is exaggerated. The first thickness T1 is, for example, 0.45 μm to 10 μm, more preferably 1 μm to 2 μm, and even more preferably 1.2 μm to 2 μm. It should be noted that the upper surface of the susceptor cover 300 can also be referred to as the "front surface" and the lower surface can also be referred to as the "back surface."

[0035] The greater the thickness of the Si oxide layer 300b, the slower the rate of increase in the thickness of the Si oxide layer 300b relative to the time of the oxidation process performed in the processing chamber 201. Therefore, the larger the first thickness T1 is, the more the fluctuation in the emissivity caused by the change in the thickness of the oxide layer on the surface of the susceptor cover 300 accompanying the oxidation process of the substrate can be suppressed. Specifically, by forming the Si oxide layer 300b with a first thickness T1 of at least 0.45 μm, a significant effect of reducing the rate of increase in the oxide layer thickness can be achieved. If the first thickness T1 is less than 0.45 μm, a significant effect of reducing the rate of increase in the thickness of the Si oxide layer 300b relative to the time of substrate processing may not be achieved. In addition, preferably, by forming the Si oxide layer 300b with a first thickness T1 of 1 μm or more, the rate of increase in the oxide layer thickness relative to the time of substrate processing can be reliably reduced to a practical level. When the first thickness T1 is smaller than 1 μm, particularly when the processing temperature is set to 600° C. or higher, the effect of sufficiently reducing the increasing rate of the thickness of the Si oxide layer 300 b relative to the substrate processing time may not be achieved.

[0036] Figure 8 This is a line graph showing the relationship between the oxidation treatment time and the oxide film pressure. As mentioned above, in order to reduce the rate of increase in the oxide layer thickness to a practical level, it is preferred that the first thickness T1 be a layer thickness greater than or equal to the saturation trend of the line graph. It should be noted that when the thickness of the Si oxide layer 300b exceeds 2μm, the effect of suppressing the oxidation rate is almost saturated. Therefore, considering the cost, time, etc. of forming the Si oxide layer 300b, it is preferred that the thickness be 2μm or less. In addition, when the thickness of the Si oxide layer 300b exceeds 10μm, it is difficult to form the Si oxide layer 300b within a practical time. Therefore, it is preferred that the thickness of the Si oxide layer 300b be 10μm or less.

[0037] The Si oxide layer 300b is formed on the upper surface of the susceptor cover 300, at least over the entire portion (entire surface) facing the substrate 200. In addition, it is more desirable that the Si oxide layer 300b is formed over the entire upper surface of the susceptor cover 300 (that is, also including the entire upper surface of the portion not facing the substrate 200). This is suitable for uniformly transferring radiant heat from the susceptor cover 300 to the substrate 200 in the direction of the substrate surface. In addition, the Si oxide layer 300b is formed in a manner to have a uniform thickness in the surface direction of the surface. Since the thickness of the Si oxide layer 300b is uneven, a deviation in the emissivity distribution occurs on the surface of the susceptor cover 300. Therefore, it is preferred that the first thickness T1 at least covers the entire portion facing the substrate 200, and more preferably uniformly covers the entire upper surface of the susceptor cover 300.

[0038] Furthermore, since the susceptor cover 300 has the Si oxide layer 300c not only on the surface (upper surface) on which the substrate 200 is mounted, but also on the surface (lower surface) on the side opposite to the susceptor 217, even if the Si oxide layer increases due to oxidation reaction on the lower surface of the susceptor cover 300 as well as on the upper surface during the oxidation process of the substrate, the rate of increase in the thickness of the oxide layer can be reduced. Therefore, even if the Si oxide layer increases due to oxidation process of the substrate on the lower surface of the susceptor cover 300 as in the present embodiment, the change in emissivity caused by the change in the thickness of the Si oxide layer on the surface of the susceptor cover 300 due to the oxidation process of the substrate can be suppressed.

[0039] Specifically, the susceptor cover 300 has a Si oxide layer 300c (a second thickness T2) on the surface (lower surface) opposite to the susceptor 217. Figure 7 ). Thus, the influence of the emissivity change on the lower surface side of the susceptor cover 300 can be reduced. The second thickness T2 is, for example, 0.45 μm to 10 μm, more preferably 1 μm to 2 μm, and even more preferably, 1.2 μm to 2 μm. By forming the Si oxide layer 300c with a thickness of at least 0.45 μm, a significant effect of reducing the rate of increase in the thickness of the oxide layer can be obtained. In the case where the second thickness T2 is less than 0.45 μm, there is a possibility that a significant effect of reducing the rate of increase in the thickness of the Si oxide layer 300c relative to the substrate processing time cannot be obtained. In addition, by appropriately forming the Si oxide layer 300c with a thickness of 1 μm or more, the rate of increase in the thickness of the oxide layer relative to the substrate processing time can be reliably reduced to a practical level. In the case where the second thickness T2 is less than 1 μm, especially under the condition that the processing temperature is 600°C or more, there is a possibility that the effect of sufficiently reducing the rate of increase in the thickness of the Si oxide layer 300c relative to the substrate processing time cannot be obtained. In addition, in order to reduce the increase rate of the oxide layer thickness to a practical level, the second thickness T2 is Figure 8 The line graph shows a saturation trend. A layer thickness greater than or equal to the thickness of the Si oxide layer 300c is preferred. It should be noted that when the thickness of the Si oxide layer 300c exceeds 2 μm, the oxidation rate suppression effect is almost saturated. Therefore, considering the cost and time required to form the Si oxide layer 300c, a thickness of 2 μm or less is preferred. Furthermore, when the thickness of the Si oxide layer 300c exceeds 10 μm, it becomes difficult to form the Si oxide layer 300c in a practical amount of time. Therefore, a thickness of 10 μm or less is preferred.

[0040] When a gas containing oxygen (O) is used during substrate processing, the upper surface of the susceptor cover 300, which is easily exposed to the O-containing gas, is more susceptible to oxidation during substrate processing. Therefore, it is preferable that the first thickness T1 is greater than the second thickness T2. On the other hand, depending on the type of gas used in substrate processing, different operating conditions, and other conditions, the lower surface of the susceptor cover 300 of the susceptor heater 217b may also be more susceptible to oxidation. In this case, it is preferable that the second thickness T2 is greater than the first thickness T1. It should be noted that when the oxide layer formation process is performed simultaneously on both sides of the susceptor cover 300, the first thickness T1 and the second thickness T2 may also be equal.

[0041] In addition, the upper surface portion 217d of the susceptor 217 can be made of a material that can transmit the infrared component of the radiant light radiated from the susceptor heater 217b. As such a material, transparent quartz, for example, can be used. In this case, the rate at which the susceptor cover 300 is heated by radiant heat is greater than in the case where the susceptor 217 is made of an opaque material that does not transmit the infrared component of the radiant light radiated from the susceptor heater 217b. Therefore, with respect to the susceptor cover 300 involved in the present disclosure that can suppress changes in emissivity caused by the passage of time, it can be more appropriately used when the susceptor 217 (more specifically, the upper surface portion 217d) is made of a material that can transmit the infrared component of the radiant light radiated from the heater.

[0042] The Si oxide layers 300 b and 300 c can be formed using this apparatus or a heating apparatus different from this apparatus, for example, by the following method.

[0043] After the susceptor cover is brought into the processing chamber, an oxidizing gas is supplied into the processing chamber. It is preferable to arrange the susceptor cover so that a Si oxide layer of uniform thickness is formed on both the upper and lower surfaces of the susceptor cover, thereby allowing both surfaces to be evenly exposed to the oxidizing gas.

[0044] · Continuously supply the oxidizing gas and heat the susceptor cover with a heater. In order to shorten the time required to form the Si oxide layer, it is preferable to heat the susceptor cover at a temperature higher than that used during substrate processing.

[0045] It should be noted that as the oxidizing gas, for example, oxygen (O2) gas, nitrous oxide (N2O) gas, nitric oxide (NO) gas, nitrogen dioxide (NO2) gas, ozone (O3) gas, water vapor (H2O gas), carbon monoxide (CO) gas, carbon dioxide (CO2) gas, etc. can be used. As the oxidizing gas, one or more of these can be used. In addition, air can be used as the oxidizing gas.

[0046] This method enables the uniform formation of a Si oxide layer having a thickness of 1 μm or greater on the surface of the susceptor cover, extending along the substrate mounting surface of the susceptor cover. While a substrate is mounted on the susceptor cover, the Si oxide layer formed on the surface of the susceptor cover during the oxidation process may not be uniformly formed along the substrate mounting surface of the susceptor cover, depending on the influence of the mounted substrate and the nature of the process. Therefore, it is desirable to form the Si oxide layer on the surface of the susceptor cover by performing the oxidation process on the surface of the susceptor cover without a substrate mounted on the susceptor cover, as in this method.

[0047] like Figure 5 、 Figure 6 As shown, a substrate support portion 300d having a first height D1 is formed on the surface (upper surface) of the susceptor cover 300 on the side where the substrate 200 is placed. This substrate support portion 300d forms a gap of the first height D1 between the susceptor cover 300 and the substrate 200. The first height D1 is 0.1 to 5 mm, and may be, for example, 1 mm. The substrate support portion 300d is formed outside the second through-hole 300a, for example, extending along the outer circumference of the susceptor cover 300. A recess 300e is formed radially inward of the substrate support portion 300d relative to the substrate support portion 300d.

[0048] Thus, when the substrate 200 is placed on the upper surface side of the susceptor cover 300, a gap is formed between the substrate 200 and the recess 300e. In this way, when there is a gap space on the upper surface side of the susceptor cover 300, during substrate processing, the upper surface of the susceptor cover 300 is exposed to the oxidizing gas present in the gap space, and thus the upper surface becomes easily oxidized. Therefore, pre-forming the Si oxide layer 300b on the upper surface side is more effective in suppressing oxidation than in the case where there is no gap space. In addition, due to the presence of the gap space, the proportion of heat radiation from the susceptor cover 300 to the substrate 200 becomes larger than the heat conduction caused by direct contact between the susceptor cover 300 and the substrate 200. Therefore, pre-forming the Si oxide layer 300b on the upper surface side is more effective in suppressing changes in heat radiation caused by the passage of time.

[0049] In addition, by pre-forming a gap of a specified height between the back surface of the substrate 200 and the upper surface of the susceptor cover 300, even if deformation of the substrate 200 or deformation of the upper surface of the susceptor cover 300 occurs, the heat from the susceptor heater 217b can be evenly transferred to the substrate 200 in the direction of the substrate surface through the gap space.

[0050] When the substrate 200 is placed on the substrate support 300d, foreign matter, for example, adhering to the upper surface of the substrate support 300d, may adhere to the back surface of the substrate 200. Furthermore, for example, gas may be trapped between the substrate 200 and the substrate support 300d, causing the substrate 200 to slide laterally. By providing the substrate support 300d with a gap (recess 300e) of a predetermined height formed on the back surface of the substrate, the adhesion of foreign matter to the back surface of the substrate 200 and the lateral sliding of the substrate 200 can be suppressed.

[0051] Furthermore, a recess 300f having a second height D2 is formed on the surface (lower surface) of the susceptor cover 300 that faces the susceptor 217. This recess 300f creates a gap of the second height D2 between the susceptor 217 and the susceptor cover 300. The second height D2 is 0.1 to 5 mm, and may be, for example, 1 mm. The recess 300f is formed radially inward of the second through-hole 300a, for example.

[0052] Thus, when the susceptor cover 300 is placed on the susceptor 217, a gap is formed between the susceptor cover 300 and the susceptor 217. In this way, when there is a gap space on the lower surface side of the susceptor cover 300, during substrate processing, the lower surface of the susceptor cover 300 is exposed to the oxidizing gas present in the gap space, and thus the lower surface becomes easily oxidized. Therefore, pre-forming the Si oxide layer 300c on the lower surface side is more effective in suppressing oxidation than in the case where there is no gap space. In addition, due to the presence of this gap space, the ratio of heat conduction caused by direct contact between the susceptor cover 300 and the susceptor 217 to heat radiation from the susceptor 217 to the susceptor cover 300 becomes larger, so pre-forming the Si oxide layer 300c on the lower surface side is more effective in suppressing changes in heat radiation caused by the passage of time.

[0053] In addition, by pre-forming a gap of a specified height between the susceptor 217 with a built-in susceptor heater 217b and the susceptor cover 300, even if deformation or surface unevenness occurs on the upper surface of the susceptor cover 300 or the susceptor 217, the heat from the susceptor heater 217b can be evenly transferred to the susceptor cover 300 in the direction of the substrate surface through the gap space.

[0054] According to this embodiment, changes in the emissivity of the susceptor cover 300 over the course of the apparatus's operation can be suppressed, thereby suppressing changes in substrate temperature. This can minimize changes in the thickness of the oxide layer formed on the substrate 200 (i.e., changes in the substrate processing results) that occur with long-term operation of the substrate processing apparatus. Furthermore, the number of temperature adjustments required to maintain a constant thickness of the oxide layer formed on the substrate 200 can be reduced. Furthermore, the frequency of replacing the silicon carbide susceptor cover 300 with a new one can be reduced.

[0055] (Processing gas supply unit)

[0056] The processing gas supply unit 120 that supplies the processing gas into the processing container 203 is configured as follows.

[0057] A gas supply head 236 is provided above the processing chamber 201, i.e., above the upper container 210. The gas supply head 236 includes a cap-shaped cover 233, a gas inlet 234, a buffer chamber 237, an opening 238, a shielding plate 240, and a gas outlet 239, and is configured to supply reaction gases into the processing chamber 201.

[0058] At the gas inlet 234, an O-containing gas supply pipe 232a, which supplies O gas as an O-containing gas, a H-containing gas supply pipe 232b, which supplies hydrogen (H)-containing gas, and an inert gas supply pipe 232c, which supplies an inert gas, are connected so that their flow rates converge. The O-containing gas supply pipe 232a is equipped with an O-containing gas supply source 250a, an MFC (mass flow controller) 252a, which serves as a flow control device, and a valve 253a, which serves as an on-off valve. The H-containing gas supply pipe 232b is equipped with an H-containing gas supply source 250b, an MFC 252b, and a valve 253b. The inert gas supply pipe 232c is equipped with an inert gas supply source 250c, an MFC 252c, and a valve 253c. A valve 243a is provided downstream of the supply pipe 232 where the O-containing gas supply pipe 232a, the H-containing gas supply pipe 232b, and the inert gas supply pipe 232c converge, and is connected to the gas inlet 234.

[0059] The processing gas supply unit 120 (gas supply system) of this embodiment is mainly composed of a gas supply head 236, an O-containing gas supply pipe 232a, a H-containing gas supply pipe 232b, an inert gas supply pipe 232c, MFCs 252a, 252b, 252c, and valves 253a, 253b, 253c, and 243a.

[0060] (Exhaust section)

[0061] A gas exhaust port 235 for exhausting the atmosphere within 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. The gas exhaust pipe 231 is provided with an APC (Automatic Pressure Controller) 242 serving 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.

[0062] The exhaust section of this embodiment is mainly composed of the gas exhaust port 235, the gas exhaust pipe 231, the APC 242, and the valve 243b. It should be noted that the vacuum pump 246 may also be included in the exhaust section.

[0063] (Plasma generation unit)

[0064] An electromagnetic field generating electrode 212, consisting of a spiral resonant coil, is installed on the outer periphery of the processing chamber 201, i.e., outside the sidewall of the upper container 210, surrounding the processing chamber 201. Connected to the electromagnetic field generating electrode 212 are an RF sensor 272, a high-frequency power supply 273, and a matching device 274 that matches the impedance and output frequency of the high-frequency power supply 273. The electromagnetic field generating electrode 212 is spaced from the outer periphery of the processing container 203 and is arranged along the outer periphery. By supplying high-frequency power (RF power), it generates an electromagnetic field within the processing container 203. In other words, the electromagnetic field generating electrode 212 of this embodiment is an electrode for an inductively coupled plasma (ICP) system.

[0065] A high-frequency power source 273 supplies RF power to the electromagnetic field generating electrode 212. An RF sensor 272 is provided on the output side of the high-frequency power source 273 to monitor the high-frequency traveling wave and reflected wave information supplied. The reflected wave power monitored by the RF sensor 272 is input to a matching device 274. Based on the reflected wave information input from the RF sensor 272, the matching device 274 controls the impedance of the high-frequency power source 273 and the frequency of the output RF power to minimize the reflected wave.

[0066] The resonant coil, serving as electromagnetic field generating electrode 212, generates standing waves of a predetermined wavelength. Therefore, the winding diameter, winding pitch, and number of turns are set so that resonance occurs at a predetermined wavelength. Specifically, the electrical length of the resonant coil is set to a length equivalent to an integer multiple of one wavelength at the predetermined frequency of the high-frequency power supplied from high-frequency power source 273.

[0067] The resonant coil, serving as the electromagnetic field generating electrode 212, has both ends electrically grounded, with at least one end being grounded via a movable joint 213. The other end of the resonant coil is fixedly connected to a ground 214. Furthermore, a movable joint 215 forms a power supply between the grounded ends of the resonant coil to fine-tune the impedance of the resonant coil.

[0068] The shielding plate 223 is provided to shield the electric field outside the resonance coil serving as the electromagnetic field generating electrode 212 .

[0069] (Control Department)

[0070] The controller 291 serving as a control unit is constructed so as to control APC242, valve 243b and vacuum pump 246 through signal line A, control the support lifting mechanism 268 through signal line B, control the heater power adjustment mechanism 276 through signal line C, control the gate valve 244 through signal line D, control the RF sensor 272, high-frequency power supply 273 and matcher 274 through signal line E, and control MFC252a~252c and valves 253a~253c, 243a through signal line F.

[0071] like Figure 2 As shown, the control unit (control means), namely controller 291, is configured as a computer including a CPU (Central Processing Unit) 291a, RAM (Random Access Memory) 291b, a storage device 291c, and an I / O port 291d. RAM 291b, storage device 291c, and I / O port 291d are configured to exchange data with CPU 291a via an internal bus 291e. An input / output device 292, such as a touch panel or display, is connected to controller 291.

[0072] The storage device 291c is comprised of, for example, a flash memory or an HDD (hard disk drive). The storage device 291c stores, in a readable manner, a control program for controlling the operation of the substrate processing apparatus, a process recipe describing the sequence and conditions for substrate processing, which will be described later, and the like. The process recipe executes each sequence of the substrate processing steps, which will be described later, on the controller 291, combining them to achieve a predetermined result, and functions as a program. Hereinafter, these process recipes, control programs, and the like are collectively referred to as a program.

[0073] The I / O port 291d is connected to the above-mentioned MFC252a~252c, valves 253a~253c, 243a, 243b, gate valve 244, APC242, vacuum pump 246, RF sensor 272, high frequency power supply 273, matcher 274, susceptor lifting mechanism 268, heater power adjustment mechanism 276, etc.

[0074] The CPU 291 a reads and executes a control program from the storage device 291 c , and is configured to read a process recipe from the storage device 291 c based on input of an operation instruction from the input / output device 292 . Then, in order to follow the contents of the read process, the CPU 291a is configured to control the opening adjustment operation of the APC 242, the opening and closing operation of the valve 243b, and the start and stop of the vacuum pump 246 through the I / O port 291d and the signal line A, the lifting operation of the susceptor lifting mechanism 268 through the signal line B, the power supply adjustment operation (temperature adjustment operation) to the susceptor heater 217b using the heater power adjustment mechanism 276 through the signal line C, the opening and closing operation of the gate valve 244 through the signal line D, the operation of the RF sensor 272, the matcher 274 and the high-frequency power supply 273 through the signal line E, the flow adjustment operation of various gases using the MFCs 252a to 252c and the opening and closing operation of the valves 253a to 253c and 243a through the signal line F, and the power supply adjustment operation (temperature adjustment operation) to the upper heater 280 using the heater power adjustment mechanism 276 through the signal line G, etc.

[0075] The controller 291 can be configured by installing the above-mentioned program stored in the external storage device 293 into 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 as recording media.

[0076] (2) Substrate processing

[0077] Next, for the substrate processing step of this embodiment, the main Figure 3 Provide explanation. Figure 3 This is a flowchart illustrating the substrate processing step of this embodiment. The substrate processing step of this embodiment is performed using the aforementioned substrate processing apparatus 100 as part of a manufacturing process for semiconductor devices such as flash memory (a method for manufacturing semiconductor devices). In the following description, the operations of the various components comprising the substrate processing apparatus 100 are controlled by the controller 291.

[0078] It should be noted that, in the substrate processing step of this embodiment, a silicon layer is previously formed on the surface of the substrate 200 to be processed. In this embodiment, this silicon layer is subjected to oxidation processing as processing using plasma.

[0079] (Substrate Loading Step S110)

[0080] First, the susceptor lifting mechanism 268 lowers the susceptor 217 to the transfer position for the substrate 200, and causes the substrate upper push pin 266 to penetrate the first through-hole 217a of the susceptor 217 and the second through-hole 300a of the susceptor cover 300. Next, the gate valve 244 is opened, and the substrate 200 is transferred from the vacuum transfer chamber adjacent to the processing chamber 201 into the processing chamber 201 using the substrate transfer mechanism (not shown). The transferred substrate 200 is supported in a horizontal position on the substrate upper push pin 266 protruding from the surface of the susceptor cover 300. Then, the susceptor lifting mechanism 268 raises the susceptor 217 to support the substrate 200 on the upper surface of the susceptor cover 300.

[0081] (Heating and Vacuum Exhaust Step S120)

[0082] Next, the substrate 200 carried into the processing chamber 201 is heated. The susceptor heater 217b is previously heated to a predetermined value within a range of, for example, 500 to 1000°C. The heat generated by the susceptor heater 217b heats the substrate 200 held on the susceptor 217 to a predetermined temperature. Here, the substrate 200 is heated to, for example, 700°C. Furthermore, while the substrate 200 is being heated, the processing chamber 201 is evacuated via the gas exhaust pipe 231 using the vacuum pump 246 to reduce the pressure within the processing chamber 201 to a predetermined value. The vacuum pump 246 is operated until at least the substrate unloading step S160, described later, is completed.

[0083] (Reaction Gas Supplying Step S130)

[0084] Next, supply of O-containing gas and H-containing gas as reaction gases is started. Specifically, valves 253 a and 253 b are opened, flow rates are controlled by MFCs 252 a and 252 b , and supply of O-containing gas and H-containing gas into the processing chamber 201 is started.

[0085] Furthermore, the opening of the APC 242 is adjusted so that the pressure in the processing chamber 201 reaches a predetermined value, and the exhaust in the processing chamber 201 is controlled. In this manner, while the processing chamber 201 is appropriately exhausted, the O-containing gas and the H-containing gas are continuously supplied until the plasma processing step S140 described later is completed.

[0086] As the O-containing gas, for example, oxygen (O 2 ) gas, nitrous oxide (N 2 O) gas, nitric oxide (NO) gas, nitrogen dioxide (NO 2 ) gas, ozone (O 3 ) gas, water vapor (H 2 O gas), carbon monoxide (CO) gas, carbon dioxide (CO 2 ) gas, etc. can be used. As the O-containing gas, one or more of these can be used.

[0087] In addition, as the H-containing gas, for example, hydrogen (H 2 ) gas, deuterium (D 2 ) gas, H 2 O gas, ammonia (NH 3 ) gas, etc. can be used. As the H-containing gas, one or more of these can be used.

[0088] (Plasma Treatment Step S140)

[0089] After the pressure in the processing chamber 201 stabilizes, high-frequency power from the high-frequency power supply 273 is applied to the electromagnetic field generating electrode 212. This creates a high-frequency electric field within the plasma generation space 201a, where the O- and H-containing gases are supplied. This electric field generates a toroidal induction plasma with the highest plasma density at a height corresponding to the electrical midpoint of the electromagnetic field generating electrode 212 within the plasma generation space. The processing gas, which contains the plasma-like O- and H-containing gases, is excited by the plasma and dissociates, generating active species such as oxygen radicals (oxygen active species) and oxygen ions, and hydrogen radicals (hydrogen active species) and hydrogen ions.

[0090] In the substrate processing space 201b, radicals and unaccelerated ions generated by the inductive plasma are uniformly supplied to the surface of the substrate 200 held on the susceptor 217. 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.

[0091] Then, after a predetermined processing time, for example, 10 to 1000 seconds, the power output from high-frequency power supply 273 is stopped, stopping the plasma discharge in processing chamber 201. Furthermore, valves 253a and 253b are closed, stopping the supply of O-containing gas and H-containing gas into processing chamber 201. The above process completes plasma processing step S140.

[0092] (Vacuum Exhaust Step S150)

[0093] After the supply of the O-containing gas and the H-containing gas is stopped, the interior of the processing chamber 201 is vacuum-exhausted through the gas exhaust pipe 231. Thus, the gas in the processing chamber 201 is exhausted to the outside of the processing chamber 201. Then, the opening of the APC 242 is adjusted to adjust the pressure in the processing chamber 201 to the same pressure as that of the vacuum transfer chamber adjacent to the processing chamber 201.

[0094] (Substrate Unloading Step S160)

[0095] When the pressure in the processing chamber 201 reaches a predetermined level, the susceptor 217 is lowered to the substrate 200 transfer position, so that the substrate 200 is supported on the substrate upper pins 266. Then, the gate valve 244 is opened, and the substrate transfer mechanism is used to transfer the substrate 200 out of the processing chamber 201. The above process completes the substrate processing step of this embodiment.

[0096] As described above, the manufacturing method of the semiconductor device of this embodiment is a manufacturing method of the semiconductor device using the above-mentioned substrate processing device 100, which has the following steps: a step of placing the substrate 200 on the susceptor cover 300; a step of heating the substrate 200 using the susceptor heater 217b; and a step of supplying oxygen-containing gas to the substrate 200 to form an oxide film on the substrate 200.

[0097] (Supplement of susceptor and susceptor cover)

[0098] Since the susceptor heater 217b itself is disposed within the susceptor 217, which is composed of two components, the substrate 200 is heated by heat conduction and heat radiation through the susceptor 217. It should be noted that the susceptor heater 217b may also be disposed in contact with the lower surface of the susceptor 217, which is composed of a single component. In this case, the substrate 200 is also heated by heat conduction and heat radiation through the susceptor 217. In either case, the susceptor heater 217b is disposed at a position where direct radiation emitted from the susceptor heater 217b can be irradiated onto at least one of the susceptor cover 300 and the substrate 200 through the susceptor 217.

[0099] [Other embodiments]

[0100] An example of an embodiment of the present disclosure has been described above, but the embodiment of the present disclosure is not limited to the above-described content, and can be implemented with various modifications other than the above-described content without departing from the spirit and scope.

[0101] The above embodiments describe an example of oxidation treatment of a film formed on a substrate using a plasma of a reactive gas containing oxygen. However, the technology of the present disclosure is not limited to this and can be suitably applied to treatments for oxidizing the surface of a susceptor cover during substrate processing of a substrate placed on a SiC susceptor cover. For example, the susceptor cover of the present disclosure can be used when depositing a film on the surface of a substrate placed on the susceptor cover using an oxidizing agent, or when etching a film formed on the substrate surface using a gas containing an oxidizing agent.

[0102] The disclosure of Japanese Patent Application No. 2020-55165 filed on March 25, 2020 is incorporated herein by reference in its entirety.

[0103] All documents, patent applications, and technical standards described in this specification are incorporated by reference to the same extent as if each individual document, patent application, or technical standard was specifically and individually indicated to be incorporated by reference.

Claims

1. A substrate processing apparatus comprising: a processing chamber in which the substrate is received; a substrate mounting table disposed in the processing chamber and heated by a heater; and a substrate stage cover arranged on the upper surface of the substrate stage and configured to place the substrate on the upper surface; The substrate mounting table cover is made of silicon carbide and has a silicon oxide layer of a predetermined first thickness on at least a surface on a side on which the substrate is mounted. The substrate stage cover has a silicon oxide layer having a second thickness on a surface opposite to the upper surface of the substrate stage. A recess is provided on a surface of the substrate stage cover on a side opposite to the substrate stage so as to form a gap of a second height between at least a portion of the surface on the side opposite to the substrate stage and an upper surface of the substrate stage. The substrate stage cover is provided so as to be attachable to and detachable from the substrate stage.

2. The substrate processing apparatus according to claim 1, wherein: The heater is provided inside the substrate mounting table.

3. The substrate processing apparatus according to claim 1, wherein: The silicon oxide layer is formed on the entire surface of the side on which the substrate is placed, at least on a portion facing the substrate.

4. The substrate processing apparatus according to claim 3, wherein: The silicon oxide layer is formed on the entire surface of the side on which the substrate is placed.

5. The substrate processing apparatus according to claim 3 or 4, wherein: The silicon oxide layer is formed to have a uniform thickness on the surface on which the substrate is placed.

6. The substrate processing apparatus according to claim 1, wherein: The first thickness is 1 μm or greater.

7. The substrate processing apparatus according to claim 1, wherein: The first thickness is greater than the second thickness.

8. The substrate processing apparatus according to claim 1, wherein: The second thickness is greater than the first thickness.

9. The substrate processing apparatus according to claim 1, wherein: The substrate mounting table is made of a material that can transmit an infrared component of the radiation light emitted from the heater.

10. The substrate processing apparatus according to claim 9, wherein: The substrate mounting table is made of transparent quartz.

11. The substrate processing apparatus according to claim 1, wherein: A substrate support portion configured to support the substrate on its upper surface is provided on the surface of the substrate stage cover on the side on which the substrate is placed, so that a gap of a first height is formed between at least a portion of the surface on which the substrate is placed and the back surface of the substrate.

12. The substrate processing apparatus according to claim 1, comprising: a gas supply unit configured to supply an oxygen-containing gas into the processing chamber; and The control unit is configured to control the gas supply unit so as to supply the oxygen-containing gas into the processing chamber in a state where the substrate is placed on the substrate placing table cover.

13. A substrate stage cover, the cover being arranged on an upper surface of a substrate stage that supports a substrate in a processing chamber and is heated by a heater, so that the substrate is placed on the upper surface. The substrate mounting table cover is made of silicon carbide and has a silicon oxide layer of a predetermined first thickness on at least a surface on a side on which the substrate is mounted. The substrate stage cover has a silicon oxide layer having a second thickness on a surface opposite to the upper surface of the substrate stage. A recess is provided on a surface of the substrate stage cover on a side opposite to the substrate stage so as to form a gap of a second height between at least a portion of the surface on the side opposite to the substrate stage and an upper surface of the substrate stage. The substrate stage cover is provided so as to be attachable to and detachable from the substrate stage.

14. A treatment method comprising the following steps: a step of placing a substrate on a substrate stage cover, the substrate stage cover being arranged on an upper surface of a substrate stage heated by a heater in a processing chamber so as to place the substrate on the upper surface; a step of heating the substrate placed on the substrate stage cover using the heater; and supplying a gas containing oxygen to the substrate to form an oxide film on the substrate, in, The substrate mounting table cover is made of silicon carbide and has a silicon oxide layer of a predetermined first thickness on at least a surface on a side on which the substrate is mounted. The substrate stage cover has a silicon oxide layer having a second thickness on a surface opposite to the upper surface of the substrate stage. A recess is provided on a surface of the substrate stage cover on a side opposite to the substrate stage so as to form a gap of a second height between at least a portion of the surface on the side opposite to the substrate stage and an upper surface of the substrate stage. The substrate stage cover is provided so as to be attachable to and detachable from the substrate stage.

15. A method for manufacturing a semiconductor device, comprising the following steps: a step of placing a substrate on a substrate stage cover, the substrate stage cover being arranged on an upper surface of a substrate stage heated by a heater in a processing chamber so as to place the substrate on the upper surface; a step of heating the substrate placed on the substrate stage cover using the heater; and supplying a gas containing oxygen to the substrate to form an oxide film on the substrate, in, The substrate mounting table cover is made of silicon carbide and has a silicon oxide layer of a predetermined first thickness on at least a surface on a side on which the substrate is mounted. The substrate stage cover has a silicon oxide layer having a second thickness on a surface opposite to the upper surface of the substrate stage. A recess is provided on a surface of the substrate stage cover on a side opposite to the substrate stage so as to form a gap of a second height between at least a portion of the surface on the side opposite to the substrate stage and an upper surface of the substrate stage. The substrate stage cover is provided so as to be attachable to and detachable from the substrate stage.

16. A computer-readable recording medium having recorded thereon a program capable of causing a computer to execute the following steps: placing a substrate on a substrate stage cover, the substrate stage cover being configured to be arranged on an upper surface of a substrate stage heated by a heater in a processing chamber so as to place the substrate on the upper surface; a step of heating the substrate placed on the substrate stage cover using the heater; and supplying a gas containing oxygen to the substrate to form an oxide film on the substrate, in, The substrate mounting table cover is made of silicon carbide and has a silicon oxide layer of a predetermined first thickness on at least a surface on a side on which the substrate is mounted. The substrate stage cover has a silicon oxide layer having a second thickness on a surface opposite to the upper surface of the substrate stage. A recess is provided on a surface of the substrate stage cover on a side opposite to the substrate stage so as to form a gap of a second height between at least a portion of the surface on the side opposite to the substrate stage and an upper surface of the substrate stage. The substrate stage cover is provided so as to be attachable to and detachable from the substrate stage.

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