Substrate processing device, substrate processing method, method for manufacturing semiconductor device, and program

Abstract

Provided is technology comprising: a processing chamber for processing a substrate by using gas; a plasma generation unit for bringing the gas into a plasma state; a supply pipe that is provided upstream of the processing chamber; an exhaust pipe that is provided downstream of the processing chamber; a valve that is provided downstream of the exhaust pipe; and an attenuation unit that is provided at a position in the exhaust pipe closer to the valve than the processing chamber, or is provided upstream of a connection portion between the supply pipe and the processing chamber, the attenuation unit attenuating the energy of the plasma-state gas.

Description

Substrate processing apparatus, substrate processing method, semiconductor device manufacturing method and program

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

[0002] 2. Description of the Related Art In a substrate processing apparatus used in one step of a semiconductor device manufacturing process, a predetermined process is sometimes performed on a substrate using plasma-excited gas (see, for example, Patent Document 1).

[0003] JP 2022-144780 A

[0004] The present disclosure provides a technique capable of suppressing deterioration of device components caused by plasma.

[0005] According to one aspect of the present disclosure, there is provided a technology having: a processing chamber for processing a substrate with a gas; a plasma generating unit for converting the gas into a plasma state; a supply pipe provided upstream of the processing chamber; an exhaust pipe provided downstream of the processing chamber; a valve provided downstream of the exhaust pipe; and an attenuation unit for attenuating energy of the gas in the plasma state, the attenuation unit being provided at a position on the exhaust pipe closer to the valve than the processing chamber or being provided upstream of a connection between the supply pipe and the processing chamber.

[0006] According to the present disclosure, it is possible to suppress deterioration of device components caused by plasma.

[0007] 1 is a schematic configuration diagram of a substrate processing apparatus according to a first embodiment of the present disclosure, showing a processing furnace portion in a longitudinal cross section; FIG. 2 is a schematic configuration diagram of a controller in the substrate processing apparatus according to the first embodiment of the present disclosure, showing a control system of the controller in a block diagram; FIG. 3 is a flow diagram showing a substrate processing process according to the first embodiment of the present disclosure; FIG. 4 is an explanatory diagram showing an example of a substrate processed in the substrate processing process according to the first embodiment of the present disclosure, where (A) is a cross-sectional view of the substrate on which a recess is formed, and (B) is a cross-sectional view of the substrate when the substrate in (A) is subjected to the substrate processing process; FIG. 5 is a configuration diagram of an exhaust unit in the substrate processing apparatus according to the first embodiment of the present disclosure, showing an enlarged view of portion G in FIG. 1; FIG. 6 is an explanatory diagram showing an example of the configuration of an attenuation unit in the substrate processing apparatus according to the first embodiment of the present disclosure, where (A) is a perspective view showing the schematic configuration, and (B) is a side cross-sectional view showing the cross-sectional configuration; FIG. 7 is an explanatory diagram showing another example of the configuration of the attenuation unit in the substrate processing apparatus according to the first embodiment of the present disclosure; FIG. 8 is an explanatory diagram showing yet another example of the configuration of the attenuation unit in the substrate processing apparatus according to the first embodiment of the present disclosure, where (A) is a schematic view showing the schematic configuration, and (B) is a schematic view showing another schematic configuration. 1 is a schematic configuration diagram of a substrate processing apparatus according to a second embodiment of the present disclosure, showing a longitudinal cross-sectional view of a processing furnace portion; FIG. 2 is a schematic configuration diagram of a main part of a substrate processing apparatus according to a third embodiment of the present disclosure, showing a schematic configuration of a plasma generation unit; FIG. 3 is a schematic configuration diagram of a main part of a substrate processing apparatus according to a fourth embodiment of the present disclosure, showing a schematic configuration of a gas supply unit;

[0008] Hereinafter, one embodiment of the present disclosure will be described with reference to the drawings. Note that all drawings used in the following description are schematic, and the dimensional relationships, ratios, etc. of elements shown in the drawings do not necessarily correspond to the actual ones. Furthermore, the dimensional relationships, ratios, etc. of elements between multiple drawings do not necessarily correspond to the actual ones.

[0009] First Embodiment First, a first embodiment of the present disclosure will be specifically described.

[0010] (1) Substrate Processing Apparatus A substrate processing apparatus according to a first embodiment will be described below with reference to Fig. 1. Fig. 1 is a schematic diagram of the substrate processing apparatus according to the first embodiment.

[0011] The substrate processing apparatus 100 according to this embodiment is configured to mainly perform oxidation processing on a film formed on the surface of a wafer 200 serving as a substrate.

[0012] (Processing Chamber) The substrate processing apparatus 100 includes a processing furnace 202 for performing plasma processing on wafers 200. The processing furnace 202 is provided with a processing vessel 203 that constitutes a processing chamber 201. The processing vessel 203 includes a dome-shaped upper vessel 210 that is a first vessel, and a bowl-shaped lower vessel 211 that is a second vessel. The processing chamber 201 is formed by the upper vessel 210 covering the lower vessel 211. The upper vessel 210 is made of, for example, aluminum oxide (Al ２ O ３ ) or quartz (SiO ２ The lower container 211 is made of, for example, aluminum (Al).

[0013] A gate valve 244 is provided on the lower sidewall of the lower vessel 211. When the gate valve 244 is open, a transfer mechanism (not shown) can be used to load the wafer 200 into the processing chamber 201 or load the wafer 200 out of the processing chamber 201 via a load / unload port 245. When the gate valve 244 is closed, the gate valve 244 functions as a sluice valve that maintains the airtightness of the processing chamber 201.

[0014] The processing chamber 201 has a plasma generation space 201a around which a resonant coil 212 is provided, and a substrate processing space 201b that communicates with the plasma generation space 201a and in which the wafer 200 is processed. The plasma generation space 201a is a space in which plasma is generated, and refers to the space within the processing chamber that is above the lower end of the resonant coil 212 and below the upper end of the resonant coil 212. On the other hand, the substrate processing space 201b is a space in which the wafer 200 is processed using plasma, and refers to the space below the lower end of the resonant coil 212. In this embodiment, the plasma generation space 201a and the substrate processing space 201b are configured to have approximately the same horizontal diameter.

[0015] (Susceptor) A susceptor 217 is disposed at the center of the bottom side of the processing chamber 201 as a substrate mounting portion for mounting the wafer 200. The susceptor 217 is formed from a non-metallic material such as aluminum nitride (AlN), ceramics, or quartz, and is configured to reduce metal contamination of films formed on the wafer 200.

[0016] A heater 217b serving as a heating mechanism is integrally embedded inside the susceptor 217. The heater 217b is configured to heat the surface of the wafer 200 to, for example, about 25°C to 750°C when power is supplied thereto.

[0017] The susceptor 217 is electrically insulated from the lower chamber 211. The impedance adjustment electrode 217c is provided inside the susceptor 217 to further improve the uniformity of the density of the plasma generated above the wafer 200 placed on the susceptor 217, and is grounded via an impedance variable mechanism 275 serving as an impedance adjustment unit. The impedance variable mechanism 275 is composed of a coil and a variable capacitor. By adjusting the impedance variable mechanism 275, the potential (bias voltage) of the wafer 200 can be controlled via the impedance adjustment electrode 217c and the susceptor 217.

[0018] The susceptor 217 is provided with a susceptor lifting mechanism 268 having a drive mechanism for raising and lowering the susceptor. The susceptor 217 is also provided with a through-hole 217a, and wafer push-up pins 266 are provided on the bottom surface of the lower container 211. When the susceptor 217 is lowered by the susceptor lifting mechanism 268, the wafer push-up pins 266 are configured to pass through the through-holes 217a without coming into contact with the susceptor 217. The substrate placement portion according to this embodiment is mainly configured by the susceptor 217, the heater 217b, and the impedance electrode 217c.

[0019] (Gas Supply Section) A gas supply head 236 is provided above the processing chamber 201, i.e., on top of the upper vessel 210. The gas supply head 236 includes a cap-shaped lid 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 be able to supply processing gas into the processing chamber 201. The buffer chamber 237 functions as a dispersion space that disperses the processing gas introduced from the gas inlet 234.

[0020] The downstream end of the gas supply pipe 232 is connected to the gas inlet 234. That is, the gas supply pipe 232 is provided on the upstream side of the processing chamber 201. The downstream end of an oxygen-containing gas supply pipe 232a for supplying an oxygen (O)-containing gas, the downstream end of a hydrogen-containing gas supply pipe 232b for supplying a hydrogen (H)-containing gas, and an inert gas supply pipe 232c for supplying an inert gas are connected to the upstream end of the gas supply pipe 232 so that they converge. The oxygen-containing gas supply pipe 232a is provided with, from the upstream side, an O-containing gas supply source 250a, a mass flow controller (MFC) 252a as a flow rate control device, and a valve 253a as an on-off valve. The hydrogen-containing gas supply pipe 232b is provided with, from the upstream side, an H-containing gas supply source 250b, an MFC 252b, and a valve 253b. The inert gas supply pipe 232c is provided with an inert gas supply source 250c, an MFC 252c, and a valve 253c, in this order from the upstream side. A valve 243a is provided downstream of where the oxygen-containing gas supply pipe 232a, the hydrogen-containing gas supply pipe 232b, and the inert gas supply pipe 232c join, and is connected to the upstream end of the gas inlet 234. By opening and closing the valves 253a, 253b, 253c, and 243a, processing gases such as an O-containing gas, an H-containing gas, and an inert gas can be supplied into the processing chamber 201 via the gas supply pipes 232a, 232b, and 232c while adjusting the flow rates of the respective gases using the MFCs 252a, 252b, and 252c.

[0021] The oxygen-containing gas supply system according to this embodiment is mainly constituted by the oxygen-containing gas supply pipe 232a, the MFC 252a, and the valve 253a. Furthermore, the hydrogen-containing gas supply system according to this embodiment is constituted by the gas supply pipe 232, the hydrogen-containing gas supply pipe 232b, the MFC 252b, and the valve 253b. Furthermore, the gas supply pipe 232, the inert gas supply pipe 232c, the MFC 252c, and the valve 253c constitute an inert gas supply system according to this embodiment.

[0022] The process gas supply unit (process gas supply system) of this embodiment is mainly configured by either an oxygen-containing gas supply system or a hydrogen-containing gas supply system, or a combination thereof. The process gas supply unit may also include any one of the gas supply head 236 (the cover 233, the gas inlet 234, the buffer chamber 237, the opening 238, the shielding plate 240, and the gas outlet 239), the MFCs 252a, 252b, and 252c, and an inert gas supply system, or a combination thereof.

[0023] (Exhaust section) A gas exhaust port 235 is provided on the sidewall of the lower vessel 211 to exhaust the processing gas from inside the processing chamber 201. The upstream end of a gas exhaust pipe 231 is connected to the gas exhaust port 235. In other words, the gas exhaust pipe 231 is provided on the downstream side of the processing chamber 201 and is configured to communicate with the inside of the processing chamber 201 via the gas exhaust port 235.

[0024] The gas exhaust pipe 231 is provided with, in order from the upstream side, an APC (Auto Pressure Controller) valve 242 as a pressure regulator (pressure adjustment unit), a sub-valve 243b as an on-off valve, a first pump 246 as a vacuum exhaust device, a main valve 243c as an on-off valve, and a second pump 247 as a vacuum exhaust device. The main valve 243c is provided on the downstream side of the gas exhaust pipe 231 (i.e., on the side closer to the second pump 247 located at the downstream end of the gas exhaust pipe 231).

[0025] The first pump 246 is configured to create a high or ultra-high vacuum inside the processing chamber 201 and is, for example, a turbomolecular pump. The sub-valve 243b functions as an on-off valve associated with the first pump 246 and is, for example, a butterfly valve. The second pump 247 functions as a roughing vacuum pump that evacuates air from atmospheric pressure to supplement the operation of the first pump 246 and is, for example, a dry vacuum pump. The main valve 243c functions as an on-off valve associated with the second pump 247 and is, for example, a piston valve that opens and closes by sliding a valve body.

[0026] In this way, gas exhaust pipe 231 is provided with at least first pump 246, main valve 243c, and second pump 247. As a result, gas exhaust pipe 231 has first exhaust pipe 231a connecting gas exhaust port 235 and first pump 246, second exhaust pipe 231b connecting first pump 246 and main valve 243c, and third exhaust pipe 231c connecting main valve 243c and second pump 247.

[0027] Furthermore, an attenuation section 248 is provided in the gas exhaust pipe 231 at a position closer to the main valve 243c than to the processing chamber 201 in the gas exhaust pipe 231. More specifically, the attenuation section 248 is provided in the second exhaust pipe 231b. The attenuation section 248 will be described in detail later.

[0028] The exhaust unit according to this embodiment is mainly composed of the gas exhaust port 235, the gas exhaust pipe 231, and the sub-valve 243b. The exhaust unit may also include the APC valve 242, the first pump 246, and the main valve 243c. Furthermore, the exhaust unit may also include the second pump 246.

[0029] (Plasma Generation Section) A spiral resonant coil 212 serving as a first electrode is provided on the outer periphery of the processing chamber 201, i.e., on the outside of the sidewall of the upper vessel 210, so as to surround the processing chamber 201. An RF sensor 272, a high-frequency power supply 273, and a matching box 274 that matches the impedance and output frequency of the high-frequency power supply 273 are connected to the resonant coil 212.

[0030] The high-frequency power supply 273 supplies high-frequency power (RF power) to the resonant coil 212. The RF sensor 272 is provided on the output side of the high-frequency power supply 273 and monitors information on the forward and reflected high-frequency waves being supplied. The reflected wave power monitored by the RF sensor 272 is input to a matching device 274, which controls the impedance of the high-frequency power supply 273 and the frequency of the output high-frequency power based on the information on the reflected wave input from the RF sensor 272 so as to minimize the reflected wave.

[0031] The winding diameter, winding pitch, and number of turns of the resonance coil 212 are set so that the resonance coil 212 resonates at a certain wavelength to form a standing wave of a predetermined wavelength. That is, the electrical length of the resonance coil 212 is set to a length corresponding to an integer multiple (1x, 2x, ...) of one wavelength at a predetermined frequency of the high frequency power supplied from the high frequency power supply 273.

[0032] Both ends of the resonant coil 212 are electrically grounded, and at least one end of the resonant coil is grounded via a movable tap 213 to fine-tune the electrical length of the resonant coil when the apparatus is initially installed or when processing conditions are changed. Reference numeral 214 in FIG. 1 denotes the other fixed ground. The position of the movable tap 213 is adjusted so that the resonance characteristics of the resonant coil 212 are approximately equal to those of the high-frequency power supply 273. Furthermore, a power supply unit is formed between the grounded ends of the resonant coil 212 by a movable tap 215 to fine-tune the impedance of the resonant coil 212 when the apparatus is initially installed or when processing conditions are changed. The resonant coil 212 includes a variable ground unit and a variable power supply unit, which makes it easier to adjust the resonant frequency and load impedance of the processing chamber 201.

[0033] The plasma generating unit (plasma generating mechanism) according to this embodiment is mainly constituted by the resonance coil 212, the RF sensor 272, and the matching box 274. The plasma generating unit may also include a high frequency power supply 273.

[0034] With this configuration, the resonant coil 212 in this embodiment is supplied with high-frequency power at the actual resonant frequency of the resonant coil, including the plasma (or is supplied with high-frequency power that matches the actual impedance of the resonant coil, including the plasma), so a standing wave is formed in which the phase voltage and the anti-phase voltage are always canceled out. When the electrical length of the resonant coil 212 is the same as the wavelength of the high-frequency power, the highest phase current is generated at the electrical midpoint of the coil (the node where the voltage is zero). Therefore, near the electrical midpoint, there is almost no capacitive coupling with the process chamber wall or the susceptor 217, and a donut-shaped induction plasma with an extremely low electrical potential is formed.

[0035] That is, in this embodiment, the plasma generating unit is configured to have a resonant coil 212 capable of generating plasma in the processing chamber 201. Then, by supplying high frequency power to the resonant coil 212, inductively coupled plasma (ICP) is generated.

[0036] (Controller) The substrate processing apparatus 100 includes a controller 221 that functions as a controller (control means) that controls the operation of each part of the substrate processing apparatus 100 .

[0037] The controller 221 is configured to control the APC valve 242, the valves 243b, 243c, the first pump 246, and the second pump 247 via signal line A, the susceptor lifting mechanism 268 via signal line B, the heater power adjustment mechanism 276 and the impedance variable mechanism 275 via signal line C, the gate valve 244 via signal line D, the RF sensor 272, the high-frequency power supply 273, and the matching box 274 via signal line E, and the MFCs 252a to 252c and the valves 253a to 253c, 243a via signal line F.

[0038] Fig. 2 is a block diagram showing a schematic configuration of the controller 221. As shown in Fig. 2, the controller 221, which is a control unit (control means), is configured as a computer including a CPU (Central Processing Unit) 221a, a RAM (Random Access Memory) 221b, a storage device 221c, and an I / O port 221d. The RAM 221b, the storage device 221c, and the I / O port 221d are configured to be able to exchange data with the CPU 221a via an internal bus 221e. An input / output device 225 configured as, for example, a touch panel or a display is connected to the controller 221.

[0039] The storage device 221c is composed of, for example, a flash memory, an HDD (Hard Disk Drive), etc. The storage device 221c readably stores a control program for controlling the operation of the substrate processing apparatus, a program recipe describing the procedures and conditions of the substrate processing described below, and the like. The process recipe is a combination of procedures in the substrate processing process described below that are executed by the controller 221 to obtain a predetermined result, and functions as a program. Hereinafter, the program recipe, control program, etc. are collectively referred to simply as a program. Note that, when the term "program" is used in this specification, it may refer to only the program recipe, only the control program, or both. The RAM 221b is configured as a memory area (work area) in which programs, data, etc. read by the CPU 221a are temporarily stored.

[0040] The I / O port 221d is connected to the above-mentioned MFCs 252a to 252c, valves 253a to 253c, 243a, 243b, and 243c, gate valve 244, APC valve 242, first pump 246, second pump 247, RF sensor 272, high-frequency power supply 273, matching box 274, susceptor lifting mechanism 268, impedance variable mechanism 275, heater power adjustment mechanism 276, and the like.

[0041] The CPU 221a is configured to read and execute a control program from the storage device 221c, and also to read a process recipe from the storage device 221c in response to an input of an operation command from the input / output device 225, etc. The CPU 221a is configured to be able to control, in accordance with the contents of the read process recipe, the opening adjustment operation of the APC valve 242, the opening and closing operation of the valves 243b and 243c, and the start and stop of the first pump 246 and the second pump 247 via the I / O port 221d and signal line A, the lifting and lowering operation of the susceptor lifting mechanism 268 via signal line B, the adjustment operation (temperature adjustment operation) of the amount of power supplied to the heater 217b by the heater power adjustment mechanism 276 and the impedance value adjustment operation by the impedance variable mechanism 275 via signal line C, the opening and closing operation of the gate valve 244 via signal line D, the operations of the RF sensor 272, the matching box 274, and the high-frequency power supply 273 via signal line E, and the flow rate adjustment operation of various gases by the MFCs 252a to 252c and the opening and closing operation of the valves 253a to 253c and 243a via signal line F.

[0042] The controller 221 can be configured by installing the above-mentioned program stored in an external storage device 226 (e.g., a magnetic tape, a magnetic disk such as a flexible disk or a hard disk, an optical disk such as a CD or a DVD, a magneto-optical disk such as an MO, or a semiconductor memory such as a USB memory or a memory card) into a computer. The storage device 221c and the external storage device 226 are configured as computer-readable recording media. Hereinafter, these will be collectively referred to as simply a recording medium. In this specification, when the term "recording medium" is used, it may include only the storage device 221c alone, only the external storage device 226 alone, or both. Note that the program may be provided to the computer using a communication means such as the Internet or a dedicated line, without using the external storage device 226.

[0043] (2) Substrate Processing Step Next, a substrate processing step according to the first embodiment of the present disclosure will be described mainly with reference to Fig. 3. Fig. 3 is a flow chart showing the substrate processing step according to the first embodiment of the present disclosure.

[0044] The substrate processing step according to the first embodiment is performed as one step in a manufacturing process for semiconductor devices such as flash memories by the above-described substrate processing apparatus 100. In the following description, the operation of each component of the substrate processing apparatus 100 is controlled by a controller 221.

[0045] In this substrate processing step, processing is performed on a wafer 200, for example, as shown in FIG. 4A. FIG. 4 is an explanatory diagram showing an example of a substrate processed in the substrate processing step. Specifically, a recess 301 is pre-formed on the wafer 200 as a substrate, with a silicon (Si) film 302 and a silicon nitride (SiN) film 303 formed on at least the surface, as shown in FIG. 4A. That is, in the wafer 200 processed in this substrate processing step, the Si film 302 and the SiN film 303 are exposed inside the recess 301 formed on the wafer 200, and the Si film 302 forms the bottom of the recess 301. The recess 301 is, for example, a trench or a hole, and the aspect ratio of the recess 301 is 20 or more. In this substrate processing step, an oxidation process is performed on the recess 301 using plasma. The Si film 302 is made of at least one of single-crystal silicon (c-Si), amorphous silicon (a-Si), and polycrystalline silicon (Poly-Si).

[0046] In this specification, the term "substrate" may mean "the substrate itself" or "a substrate and a predetermined layer, film, etc. formed on its surface, and a laminate (assembly) of the substrate" (i.e., the predetermined layer, film, etc. formed on the surface are referred to as the substrate). In addition, in this specification, the term "surface of the substrate" may mean "the surface (exposed surface) of the substrate itself" or "the surface of a predetermined layer, film, etc. formed on the substrate, i.e., the outermost surface of the substrate as a laminate." Therefore, in this specification, when it is stated that "a predetermined gas is supplied to the substrate," it may mean "supplying a predetermined gas directly to the surface (exposed surface) of the substrate itself" or "supplying a predetermined gas to a layer, film, etc. formed on the substrate, i.e., to the outermost surface of the substrate as a laminate." In addition, in this specification, it may mean "forming a predetermined layer (or film) on a layer, film, etc. formed on the substrate, i.e., on the outermost surface of the substrate as a laminate." In addition, when the term "wafer" is used, it is the same as when the term "substrate" is used. In this case, in the above description, "substrate" may be replaced with "wafer."

[0047] (Substrate Loading Step S110) As shown in FIG. 3, in this substrate processing step, first, the wafer 200 is loaded into the processing chamber 201.

[0048] Next, the gate valve 244 is opened, and the wafer 200 is loaded into the processing chamber 201 from a vacuum transfer chamber adjacent to the processing chamber 201 using a wafer transfer mechanism (not shown). The loaded wafer 200 is supported on the upper surface of the susceptor 217. Furthermore, the wafer transfer mechanism is retracted to the outside of the processing chamber 201, and the gate valve 244 is closed to hermetically seal the processing chamber 201.

[0049] (Heating and Vacuum Evacuation Step S120) Next, the wafer 200 loaded into the processing chamber 201 is heated. The heater 217b is preheated, and the wafer 200 is held on the susceptor 217 in which the heater 217b is embedded, thereby heating the wafer 200 to a predetermined temperature, for example, within a range of 150 to 700°C. Here, the wafer 200 is heated to a temperature of 700°C. While the wafer 200 is being heated, the vacuum pump 246 evacuates the processing chamber 201 via the gas exhaust pipe 231, and the pressure inside the processing chamber 201 is set to a predetermined value. The vacuum pump 246 is kept operating at least until the substrate unloading step S160, which will be described later, is completed. Note that in this specification, a numerical range such as "150 to 700°C" means that the lower limit and upper limit are included in the range. Therefore, for example, "150 to 700°C" means "150°C or higher and 700°C or lower." The same applies to other numerical ranges.

[0050] (Processing Gas Supply Step S130) Next, the supply of a mixed gas of an O-containing gas and an H-containing gas as a processing gas is started. That is, the mixed gas of an O-containing gas and an H-containing gas as a processing gas is supplied into the processing chamber 201 in which the wafers 200 are accommodated. Specifically, the valves 253a and 253b are opened, and the supply of the O-containing gas and the H-containing gas into the processing chamber 201 is started while controlling the flow rates with the MFCs 252a and 252b. At this time, the flow rate of the O-containing gas is set to a predetermined value within a range of, for example, 10 to 50,000 sccm, preferably 10 to 5,000 sccm. Furthermore, the flow rate of the H-containing gas is set to a predetermined value within a range of, for example, 10 to 50,000 sccm, preferably 10 to 5,000 sccm.

[0051] The ratio of O to H contained in the mixed gas of O-containing gas and H-containing gas, which is the processing gas, is adjusted by controlling the flow rate ratio of the O-containing gas and the H-containing gas. This makes it possible to easily control the ratio of O to H contained in the processing gas. The ratio of O to H is the ratio of the number of O atoms to the number of H atoms contained in the processing gas. For example, when oxygen gas (O ２ gas) and hydrogen gas (H ２When a mixed gas of O-containing gas and H-containing gas is used, the flow rate ratio of the O-containing gas to the H-containing gas directly becomes the ratio of O to H. The flow rate ratio of the O-containing gas to the H-containing gas is adjusted to a value corresponding to a predetermined thickness ratio that is acquired in advance and stored in the storage device 221c or the external storage device 226. In this way, by acquiring the flow rate ratio of the O-containing gas to the H-containing gas in advance and storing it in the storage device 221c or the external storage device 226, it becomes easy to adjust the flow rate ratio of the O-containing gas to the H-containing gas.

[0052] At this time, the aperture of the APC valve 242 is adjusted to control exhaustion from the processing chamber 201 so that the pressure inside the processing chamber 201 is set to a predetermined pressure, for example, within a range of 1 to 250 Pa, preferably 50 to 200 Pa, and more preferably approximately 150 Pa. In this manner, while the processing chamber 201 is appropriately exhausted, the supply of the O-containing gas and the H-containing gas continues until the end of the plasma processing step S140, which will be described later.

[0053] (Plasma treatment step S140) Once the pressure inside the processing chamber 201 has stabilized, application of high frequency power from the high frequency power supply 273 to the resonant coil 212 begins via the RF sensor 272. In this embodiment, high frequency power of 13.54 to 27.12 MHz is supplied from the high frequency power supply 273 to the resonant coil 212. The high frequency power supplied to the resonant coil 212 is a predetermined power within a range of, for example, 100 to 5000 W.

[0054] As a result, a high-frequency electric field is formed in the plasma generation space 201a to which the O-containing gas and the H-containing gas are supplied, and this electric field excites a donut-shaped induction plasma having the highest plasma density at a height position corresponding to the electrical midpoint of the resonant coil 212 in the plasma generation space 201a. The O-containing gas and the H-containing gas in the plasma state dissociate to generate reactive species such as oxygen active species such as oxygen (O) radicals, oxygen ions, and hydroxyl (OH) radicals, and hydrogen active species such as hydrogen (H) radicals and hydrogen ions.

[0055] That is, the process gas, which is a mixed gas of an O-containing gas and an H-containing gas supplied into the process chamber 201, is plasma-excited to generate reactive species such as activated oxygen species and activated hydrogen species. Here, by generating reactive species having an oxidizing action such as activated oxygen species and reactive species having an oxidation-inhibiting action such as activated hydrogen species, it is possible to obtain oxidation selectivity for a Si film and a SiN film.

[0056] Furthermore, by performing oxidation using activated species generated by ICP, which has an extremely low electric potential, it is possible to form an oxide layer with good uniformity on a film formed on the surface of the recess 301 having a high aspect ratio of 20 or more. Furthermore, even if the recess 301 is not formed perpendicular to the surface direction of the wafer 200, such as when the recess 301 is formed on a surface formed perpendicular to the surface direction of the wafer 200, it is possible to form an oxide layer with good uniformity on a film formed on the surface.

[0057] 4B , a SiO layer 304a of uniform thickness is formed on the entire exposed surface of the Si film 302 that forms the bottom of the recess 301, and a SiO layer 304b of uniform thickness is formed on the entire exposed surface of the SiN layer 303 that forms the sidewall surface of the recess 301. Also, a SiO layer 304a that is thicker than the SiO layer 304b formed on the exposed surface of the SiN film 303 is formed on the exposed surface of the Si film 302 that forms the bottom of the recess 301. That is, the surface of the Si film 304 can be selectively oxidized relative to the surface of the SiN film 303 to form the SiO layer 304a, which is an oxide layer.

[0058] After that, after a predetermined processing time, for example, 10 to 300 seconds, the power output from the high frequency power supply 273 is stopped to stop the plasma discharge in the processing chamber 201. Furthermore, the valves 253a and 253b are closed to stop the supply of the O-containing gas and the H-containing gas into the processing chamber 201. This completes the plasma processing step S140.

[0059] (Vacuum exhaust process S150) After the supply of the O-containing gas and the H-containing gas is stopped, the processing chamber 201 is evacuated via the gas exhaust pipe 231. This allows the O-containing gas and the H-containing gas in the processing chamber 201, as well as exhaust gases generated by the reaction of these gases, to be exhausted to the outside of the processing chamber 201. Thereafter, the aperture of the APC valve 242 is adjusted to adjust the pressure in the processing chamber 201 to the same pressure as that of a vacuum transfer chamber (the destination of the wafer 200, not shown) adjacent to the processing chamber 201.

[0060] (Substrate Unloading Process S160) When the pressure inside the processing chamber 201 reaches a predetermined level, the susceptor 217 is lowered to the transfer position for the wafer 200, and the wafer 200 is supported on the wafer lift-up pins 266. Then, the gate valve 244 is opened, and the wafer 200 is unloaded from the processing chamber 201 using the wafer transfer mechanism. This completes the substrate processing process according to this embodiment.

[0061] The O-containing gas is, for example, O ２ Gas, ozone (O ３ ) gas, water vapor (H ２ O gas), hydrogen peroxide (H ２ O ２ ) gas, nitric oxide (NO) gas, nitrous oxide (N ２ As the O-containing gas, a gas containing at least one of these can be used. As the H-containing gas, for example, H ２ Gas, H ２ O gas, H ２ O ２ Gas, deuterium (D ２ ) gas, etc. can be used. Furthermore, as the H-containing gas, a gas containing at least one of these can be used. Note that different gases are used as the O-containing gas and the H-containing gas. For example, the O-containing gas and the H-containing gas are gases that have different ratios of the number of O atoms to H atoms contained per flow rate of each gas. Furthermore, the O-containing gas and the H-containing gas are gases that have different ratios of the number of O atoms to H atoms contained in the composition (molecular structure) of each gas.

[0062] (3) Plasma Decay In the substrate processing process described above, in the plasma processing step S140, the wafer 200 is processed using a plasma-excited processing gas. At this time, if the wafer 200 to be processed has a groove-like portion with a high aspect ratio (specifically, for example, the recess 301) on its surface, it is preferable that the energy level of the radicals is high. This is because, in order to uniformly process a groove with a high aspect ratio from the top to the bottom of the groove, the radicals should be delivered deep into the groove. However, if the energy level of the radicals is low, they may be deactivated midway through the groove, and the radicals may not reach the bottom of the groove.

[0063] On the other hand, when processing the wafer 200, exhaust from the gas exhaust pipe 231 is controlled to adjust the pressure inside the processing chamber 201 to a predetermined level from the start of supply of the processing gas in the processing gas supply step S130 until the end of the plasma processing step S140. After the plasma processing step S140 is completed, the processing gas inside the processing chamber 201 is exhausted from the gas exhaust pipe 231 in a vacuum exhaust step S150. Therefore, the processing gas in a plasma state flows into the gas exhaust pipe 231, which constitutes the exhaust section.

[0064] In this case, the processing gas in a plasma state may cause a phenomenon in which the constituent members of the exhaust section are altered due to the influence of the plasma. In particular, it is thought that the degree of alteration of the constituent members of the exhaust section is large when the energy level of radicals is high.

[0065] FIG. 5 is a structural diagram of the exhaust unit in this embodiment, and is an enlarged view of portion G in FIG. 1 . As shown in FIG. 5 , in the exhaust unit, the gas exhaust pipe 231 has at least a second exhaust pipe 231b and a third exhaust pipe 231c, and a main valve 243c is provided between the second exhaust pipe 231b and the third exhaust pipe 231c. The main valve 243c includes a valve body 249a and a seal member 249b, which are disposed on an extension of the gas exhaust pipe 231 (particularly, the second exhaust pipe 231b). The operation of the valve body 249a is controlled by the controller 221. The seal member 249b may be, for example, an O-ring. The seal member 249b is disposed in a position facing the downstream end of the gas exhaust pipe 231 (particularly, the second exhaust pipe 231b).

[0066] In an exhaust section configured as described above, if the processing gas in a plasma state that has flowed into the gas exhaust pipe 231 reaches the main valve 243c as is, the plasma will attack the seal member 249b, which may result in deterioration of the seal member 249b. If the seal member 249b is altered, it may no longer be able to fully perform its intended function.

[0067] However, in this embodiment, the gas exhaust pipe 231 constituting the exhaust unit is provided with an attenuation section 248. More specifically, the attenuation section 248 is provided at a position in the gas exhaust pipe 231 closer to the main valve 243c than to the processing chamber 201, more specifically, in the second exhaust pipe 231b. In other words, the attenuation section 248 is provided at least upstream of the main valve 243c.

[0068] The attenuation section 248 attenuates the energy of the processing gas in a plasma state. If such an attenuation section 248 is provided at least upstream of the main valve 243c, even if the processing gas in a plasma state flows into the gas exhaust pipe 231, the processing gas will not reach the main valve 243c as it is. The processing gas in a plasma state that flows into the gas exhaust pipe 231 passes through the attenuation section 248, and the plasma energy is attenuated. Therefore, the processing gas reaches the main valve 243c after its energy has been attenuated by the attenuation section 248, and therefore, attack on the sealing member 249b is suppressed by the attenuation of the plasma energy.

[0069] That is, according to this embodiment, the presence of the attenuation portion 248 makes it possible to attenuate the plasma energy near the seal member 249b without affecting the atmosphere inside the processing chamber 201. As a result, even if the processing gas in a plasma state flows into the gas exhaust pipe 231, it is possible to suppress deterioration of the apparatus components, particularly deterioration of the seal member 249b of the main valve 243c, caused by the plasma.

[0070] In particular, when the seal member 249b in the main valve 243c is disposed close to the downstream opening of the second exhaust pipe 231b, as in the present embodiment, there is a concern that the seal member 249b may be easily altered. However, even in this case, by attenuating the plasma energy using the attenuation unit 248, it is possible to reliably suppress the alteration of the seal member 249b and dispel the above-mentioned concern.

[0071] Furthermore, by providing the attenuation portion 248, it is possible to suppress the deterioration of the sealing member, and therefore it is possible to supply a sufficient amount of plasma to the exposed surface of the Si film 302 that forms the bottom of the recess 301.

[0072] (Configuration of Attenuation Section) Here, the configuration of the attenuation section 248 will be described using a specific example.

[0073] FIG. 6 is an explanatory diagram showing an example of the configuration of the damping portion 248. As shown in FIGS. 6A and 6B, the damping portion 248 shown in this example includes at least a plate-shaped first structural portion 248b having a plurality of first through holes 248a and a plate-shaped second structural portion 248d having a plurality of second through holes 248c. In each structural portion 248b, 248d, the plate-shaped structures between the through holes 248a, 248c are referred to as gas collision walls 248s, 248t. The second structural portion 248d is located downstream of the first structural portion 248b in the gas flow direction in the gas exhaust pipe 231. When viewed from above in the gas flow direction, the first through holes 248a in the first structural portion 248b and the second through holes 248c in the second structural portion 248d are configured so that the first through holes 248a and the gas collision walls 248t of the second structural portion 248d at least partially overlap. For example, the above configuration may be achieved by arranging the first through-hole 248 a and the second through-hole 248 c so that they do not overlap. At least one first structural portion 248 b and one second structural portion 248 d may be provided, but multiple first structural portions 248 b and 248 d may be provided alternately as shown in the figure.

[0074] The attenuation section 248 configured as described above is used by being disposed in the gas flow path of the gas exhaust pipe 231 so that the gas flow in the gas exhaust pipe 231 passes through the first through-hole 248a and then the second through-hole 248c. When the gas passes through the attenuation section 248, some of the gas collides with the gas collision wall 248s of the first structural section 248b. The remaining gas collides with the gas collision wall 248t of the second structural section 248d because the first through-hole 248a and the gas collision wall 248t of the second structural section 248d are configured to at least partially overlap each other. This makes it possible to attenuate the plasma energy of the gas passing through the attenuation section 248.

[0075] As long as the plasma energy can be attenuated, the configuration of the attenuation portion 248 is not limited to the combination of the first structural portion 248b and the second through-hole 248c as shown in FIG.

[0076] For example, the attenuation section 248 may have a gas collision section that collides with the gas flow in the gas exhaust pipe 231. Specific examples of the gas collision section include a crank structure section that combines multiple bent portions in the gas flow direction, a curved pipe section that is formed by a single bent portion, and the like. If such a gas collision section is provided, when the gas passes through the gas collision section, the gas collides with the inner wall surface of the gas exhaust pipe 231 that forms the gas collision section. This makes it possible to attenuate the plasma energy of the gas passing through the gas collision section.

[0077] When the attenuation unit 248 has a gas collision unit, the gas collision unit may have a deactivation unit that deactivates the energy of the gas in a plasma state. Specific examples of the deactivation unit attached to the gas collision unit include a hardware configuration (e.g., a wind guide member) that increases the probability of gas colliding with the gas collision unit, a gas adsorption member attached to the gas collision unit, etc. If such a deactivation unit is included, the deactivation unit deactivates the plasma energy, which is very effective in attenuating the plasma energy.

[0078] The attenuation unit 248 may also have the following configuration: FIG. 7 is an explanatory diagram showing another example of the configuration of the attenuation unit 248. As shown in FIG. 7, the attenuation unit 248 given as an example here attenuates the plasma energy by using an inert gas. That is, the attenuation unit 248 may have an inert gas supply unit 248e that can supply an inert gas to the gas flow in the gas exhaust pipe 231. The inert gas may be, for example, nitrogen (N ２ However, the inert gas is not limited to this. ２ In addition to the above gas, rare gases such as argon (Ar) gas, helium (He) gas, neon (Ne) gas, xenon (Xe) gas, etc. can be used. If such an inert gas supply unit 248e is provided, the inert gas is supplied from the inert gas supply unit 248e to the gas passing through the gas collision unit, and the inert gas is caused to collide with the plasma, thereby attenuating the energy of the plasma.

[0079] 8 is an explanatory diagram showing yet another example of the configuration of the attenuation unit 248. As shown in FIGS. 8A and 8B, the attenuation unit 248 exemplified here attenuates plasma energy by aligning the gas flow direction opposite to the direction of gravity. That is, the attenuation unit 248 may have an ascending portion 248f in which the gas flow direction in the gas exhaust pipe 231 is opposite to the direction of gravity. If such an ascending portion 248f is provided, the gas flow can be oriented opposite to the direction of gravity, thereby increasing the collision probability of plasma in the gas and, as a result, attenuating the plasma energy of the gas.

[0080] In this embodiment, the attenuation unit 248 may be configured by any one of the above-described specific examples, or may be configured by an appropriate combination of the above-described specific examples. That is, the attenuation unit 248 may be configured to attenuate the plasma energy of the processing gas flowing through the gas exhaust pipe 231 at least upstream of the main valve 243 c.

[0081] (Location of Attenuation Section) As already mentioned, the attenuation section 248 having the above-described configuration is provided at least upstream of the main valve 243c, at a position in the gas exhaust pipe 231 closer to the main valve 243c than to the processing chamber 201. The location of the attenuation section 248 on the gas exhaust pipe 231 will be described in more detail below, giving specific examples.

[0082] In this embodiment, as shown in FIG. 1 , the APC valve 242, the sub-valve 243b, and the first pump 246 are provided on the gas exhaust pipe 231 on the processing chamber 201 side. The attenuation unit 248 is disposed downstream of the first pump 246 (i.e., closer to the main valve 243c). That is, the attenuation unit 248 is provided between the first pump 246 and the main valve 243c. More specifically, the attenuation unit 248 is provided on the second exhaust pipe 231b, which connects the first pump 246 and the main valve 243c, among the first exhaust pipe 231a, the second exhaust pipe 231b, and the third exhaust pipe 231c that configure the gas exhaust pipe 231. The first pump 246 is, for example, a turbomolecular pump. However, if the attenuation unit 248 is provided upstream of the first pump 246, there is a concern that particles generated from the attenuation unit 248 may flow back into the processing chamber 201 for some reason, and that these particles may affect substrate processing. In contrast, by arranging the attenuation unit 248 downstream of the first pump 246, even if the attenuation unit 248 increases the conductance, it is possible to reduce the effect of the attenuation unit 248 on the atmosphere in the processing chamber 201. Furthermore, if the attenuation unit 248 is provided upstream of the first pump 246, the first pump 246 must be controlled taking into account the conductance of the attenuation unit 248, which complicates the control, for example, when controlling pressure. In contrast, by arranging the attenuation unit 248 downstream of the first pump 246, it is not necessary to take the conductance of the attenuation unit 248 into account when controlling the first pump 246, and this does not lead to the complication of the control.

[0083] 5, a flow velocity fluctuation section 248g in which the flow velocity of the gas fluctuates is present upstream of the main valve 243c in the gas exhaust pipe 231. The attenuation section 248 is provided in the flow velocity fluctuation section 248g.

[0084] Flow velocity fluctuation section 248g is a section within gas exhaust pipe 231 where the flow velocity of the gas flowing through gas exhaust pipe 231 increases. In other words, flow velocity fluctuation section 248g is a section where the flow velocity of the gas downstream of flow velocity fluctuation section 248g is greater than the flow velocity of the gas upstream of flow velocity fluctuation section 248g. The configuration of flow velocity fluctuation section 248g will be described below with specific examples.

[0085] For example, flow rate fluctuation section 248g is configured by a piping section connected to the downstream side of first pump 246. In other words, flow rate fluctuation section 248g is configured by a piping section that becomes second exhaust pipe 231b. Such a piping section may increase the gas flow rate due to the influence of first pump 246, and therefore can function as flow rate fluctuation section 248g.

[0086] Furthermore, for example, upstream of flow rate fluctuation section 248g, there is a section 231d where the gas flow direction of gas exhaust pipe 231 changes. Such section 231d may constitute a part of first pump 246, or may constitute a part of second exhaust pipe 231b in gas exhaust pipe 231. In either case, such section 231d constitutes a bent pipe portion where the gas flow path in gas exhaust pipe 231 is bent. If such section 231d exists, the gas flow rate may increase in the piping portion located downstream thereof due to the change in gas flow direction, and therefore, this section can function as flow rate fluctuation section 248g.

[0087] Furthermore, for example, the downstream end of the second exhaust pipe 231b is connected to an inlet flow path 249c that constitutes the main valve 243c, and the diameter of the inlet flow path 249c (see D1 in the figure) is configured to be smaller than the diameter of the second exhaust pipe 231b (see D2 in the figure). With this configuration, the small diameter of the inlet flow path 249c may cause the flow velocity of gas in the second exhaust pipe 231b to be larger than that in the first exhaust pipe 231a, and therefore the second exhaust pipe 231b can function as the flow velocity fluctuation section 248g.

[0088] Furthermore, for example, the diameter of the second exhaust pipe 231b is configured to be smaller than the diameter of the first exhaust pipe 231a. With this configuration, the small diameter of the inlet flow path 249c may cause the gas flow velocity in the second exhaust pipe 231b to be larger than that in the first exhaust pipe 231a, and therefore the second exhaust pipe 231b can function as the flow velocity fluctuation section 248g.

[0089] In the present embodiment, the flow rate fluctuation section 248g may be configured by any one of the above-described specific examples, or may be configured by an appropriate combination of the above-described specific examples. In other words, the flow rate fluctuation section 248g may be a portion where the flow rate of the gas flowing through the gas exhaust pipe 231 locally increases, at least upstream of the main valve 243c.

[0090] If the attenuation section 248 is provided in the flow velocity fluctuation section 248g as described above, the flow velocity fluctuation section 248g is located in a region where the gas flow velocity increases, and therefore the probability of the gas colliding with the attenuation section 248 increases compared to when the flow velocity does not increase. Therefore, the attenuation efficiency of the plasma energy for the gas passing through the attenuation section 248 can be improved.

[0091] For example, if the gas flow rate increases upstream of the main valve 243c, when the gas reaches the main valve 243c as is, the increased flow rate causes a large amount of plasma to attack. Therefore, there is a concern that the amount of plasma attacking the seal member 249b and other components in the main valve 243c increases, resulting in a large amount of deformation of the seal member 249b and other components. However, in this embodiment, the attenuation unit 248 is provided in the flow rate fluctuation unit 248g as described above, thereby efficiently attenuating the plasma energy. In other words, even if the gas flow rate increases in the flow rate fluctuation unit 248g, the attenuation unit 248 can deactivate the plasma before it attacks the seal member 249b and other components. Therefore, even if the gas flow rate increases upstream of the main valve 243c, it is possible to suppress deterioration of the seal member 249b and other components due to the plasma attack.

[0092] In particular, when the second exhaust pipe 231b has a smaller diameter than the first exhaust pipe 231a, the conductance of the second exhaust pipe 231b becomes larger than that of the first exhaust pipe 231a, and the collision coefficient increases. Therefore, the second exhaust pipe 231b is more likely to deactivate the plasma than the first exhaust pipe. Furthermore, when the second exhaust pipe 231b has a smaller diameter than the first exhaust pipe 231a, a smaller attenuation section 248 can be installed, which also reduces component costs.

[0093] As described above, the damping section 248 is provided in the second exhaust pipe 231b connecting the first pump 246 and the main valve 243c. In this case, from the viewpoint of suppressing deterioration of the seal member 249b of the main valve 243c, the damping section 248 is preferably located immediately before the main valve 243c. Furthermore, considering that the flow rate fluctuation section 248g is located upstream of the main valve 243c, the damping section 248 is preferably provided in the flow rate fluctuation section 248g. With this arrangement, the damping section 248 can reliably suppress deterioration of the seal member 249b of the main valve 243c.

[0094] (4) Effects of the Present Embodiment The present embodiment provides one or more of the following effects.

[0095] (a) According to this embodiment, the attenuation section 248 is provided in the gas exhaust pipe 231 at a position closer to the main valve 243c than to the processing chamber 201, and therefore the energy of the plasma-state processing gas flowing through the gas exhaust pipe 231 can be attenuated without affecting the atmosphere in the processing chamber 201. As a result, even if the plasma-state processing gas flows into the gas exhaust pipe 231, deterioration of the apparatus components due to plasma, particularly deterioration of the seal member 249b of the main valve 243c, can be suppressed.

[0096] (b) According to this embodiment, since the attenuation section 248 is provided in the flow velocity fluctuation section 248g, even if the gas flow velocity increases in the flow velocity fluctuation section 248g, the attenuation section 248 can deactivate the plasma before the plasma attacks the sealing member 249b, etc. In other words, the flow velocity fluctuation section 248g increases the probability of gas collisions in the attenuation section 248, thereby increasing the efficiency of attenuation of plasma energy. Therefore, this is very useful in suppressing deterioration of the sealing member 249b, etc., due to plasma attack.

[0097] (c) According to this embodiment, the flow velocity fluctuation section 248g is configured by, for example, a piping section connected downstream of the first pump 246, a piping section downstream of the portion 231d where the gas flow direction changes, a section of the second exhaust pipe 231b having a larger diameter than the inlet flow path 249c of the main valve 243c, and a section of the second exhaust pipe 231b having a smaller diameter than the first exhaust pipe 231a. Therefore, the flow velocity of the gas can be increased in the flow velocity fluctuation section 248g, thereby increasing the probability of gas collisions. In other words, this is very useful for increasing the efficiency of attenuation of plasma energy.

[0098] (d) According to this embodiment, the valve body 249a and the seal member 249b of the main valve 243c are positioned on an extension of the gas exhaust pipe 231 (particularly the second exhaust pipe 231b), and even if the seal member 249b is positioned opposite the downstream outlet of the second exhaust pipe 231b, the attenuation section 248 attenuates the plasma energy, thereby suppressing deterioration of the seal member 249b, etc. due to plasma attack.

[0099] (e) According to the present embodiment, the attenuation section 248 is provided in the second exhaust pipe 231b, and therefore the attenuation section 248 is disposed downstream of the first pump 246. Therefore, even if the attenuation section 248 increases the conductance, it is possible to reduce the influence of the attenuation section 248 on the atmosphere in the processing chamber 201. Furthermore, it is not necessary to take the conductance of the attenuation section 248 into consideration when controlling the first pump 246, and this does not lead to complication of the control.

[0100] (f) According to this embodiment, because the second exhaust pipe 231b has a smaller diameter than the first exhaust pipe 231a, the conductance of the second exhaust pipe 231b is larger than that of the first exhaust pipe 231a, which increases the collision coefficient in the second exhaust pipe 231b. Therefore, if the attenuation section 248 is provided in the second exhaust pipe 231b, it becomes easier to deactivate the plasma compared to when it is provided in the first exhaust pipe 231a. Furthermore, if the second exhaust pipe 231b has a smaller diameter than the first exhaust pipe 231a, a smaller attenuation section 248 can be installed, which also reduces component costs.

[0101] (g) According to this embodiment, the attenuation unit 248 is configured, for example, as one having a first structural portion 248b and a second structural portion 248d, one having a gas collision portion that collides with the gas flow in the gas exhaust pipe 231, one having a deactivation portion attached to the gas collision portion, one having an inert gas supply portion 248e that can supply an inert gas to the gas flow, one having an ascending portion 248f in which the gas flow direction in the gas exhaust pipe 231 is opposite to the direction of gravity, etc. The attenuation unit 248 configured in this way can increase the collision probability of plasma in the gas, and can deactivate the plasma to reliably attenuate the energy of the plasma.

[0102] (h) According to this embodiment, the plasma generation unit includes a resonant coil 212 capable of generating plasma within the processing chamber 201, and ICP generation is performed using the resonant coil 212. When using ICP, a large number of radicals can be generated, so processing can be performed appropriately even when processing a wafer 200 having a high-aspect-ratio recess 301 on its surface. However, generating a large number of radicals using ICP can increase the amount of deformation caused by the amount of radicals. However, according to this embodiment, an attenuation unit 248 is provided that attenuates the plasma energy, so that even when using ICP, deterioration of the device components due to plasma, particularly deterioration of the seal member 249b of the main valve 243c, can be suppressed.

[0103] Second Embodiment Next, a second embodiment of the present disclosure will be specifically described. Here, differences from the first embodiment described above will be mainly described, and descriptions of other points will be omitted.

[0104] The substrate processing apparatus 100 according to the second embodiment differs from the first embodiment in the configuration of the exhaust unit. Fig. 9 is a schematic diagram of a substrate processing apparatus according to the second embodiment.

[0105] The exhaust unit in this embodiment is configured to include a gas exhaust port 235, a gas exhaust pipe 231, and an APC valve 242. The exhaust unit may also include a main valve 243c and a second pump 246. As described above, in this embodiment, the exhaust unit is not provided with the sub-valve 243b and first pump 246 described in the first embodiment.

[0106] However, the attenuation unit 248 and the flow rate fluctuation unit 248g are configured in the same manner as in the first embodiment. That is, the attenuation unit 248 is provided in a position in the gas exhaust pipe 231 closer to the main valve 243c than to the processing chamber 201, more specifically, in the second exhaust pipe 231b, and is located upstream of (preferably just before) the main valve 243c. At this position, the attenuation unit 248 attenuates the plasma energy of the gas passing through. Also in this embodiment, the gas exhaust pipe 231 has a flow rate fluctuation unit 248g located upstream of the main valve 243c. The attenuation unit 248 is provided in the flow rate fluctuation unit 248g.

[0107] In this embodiment as described above, one or more of the effects described in the first embodiment can be achieved.

[0108] Third Embodiment Next, a third embodiment of the present disclosure will be specifically described. Here, too, differences from the first or second embodiment described above will be mainly described, and descriptions of other points will be omitted.

[0109] The substrate processing apparatus 100 described in this embodiment differs from the first or second embodiment in the configuration of the plasma generating unit. Fig. 10 is a configuration diagram of a main part of a substrate processing apparatus according to the third embodiment.

[0110] In this embodiment, a spiral first resonant coil (hereinafter also simply referred to as the "first coil") 212a and a spiral second resonant coil (hereinafter also simply referred to as the "second coil") 212b adjacent to the first coil 212a are provided on the outer periphery of the processing chamber 201, i.e., on the outside of the sidewall of the upper vessel 210, so as to surround the processing chamber 201. An RF sensor 272a, a high-frequency power supply 273a, and a matching box 274a are connected to the first coil 212a, and ICP is generated in the processing chamber 201 when high-frequency power is supplied to the first coil 212a. Furthermore, an RF sensor 272b, a high-frequency power supply 273b, and a matching box 274b are connected to the second coil 212b, and ICP is generated in the processing chamber 201 when high-frequency power is supplied to the second coil 212b.

[0111] That is, in this embodiment, the plasma generation unit is configured to include a first coil 212a capable of generating plasma in the processing chamber 201, and a second coil 212b adjacent to the first coil 212a and capable of generating plasma in the processing chamber 201. Other configurations may be the same as those in the first or second embodiment.

[0112] According to this embodiment having such a configuration, the first coil 212 a and the second coil 212 b function as a double coil, thereby increasing the amount of radicals in the ICP, which is extremely useful in that it allows appropriate processing even when a large number of radicals are required, such as when processing a wafer 200 having a high aspect ratio recess 301 on its surface.

[0113] Furthermore, even if the amount of radicals in the ICP increases, the presence of the attenuation section 248 can suppress deterioration of the device components, particularly deterioration of the seal member 249b of the main valve 243c, caused by plasma. In other words, this embodiment also achieves one or more of the effects described in the first or second embodiment.

[0114] Next, a fourth embodiment of the present disclosure will be described in detail. Here, too, differences from the first, second, or third embodiment will be mainly described, and descriptions of other aspects will be omitted.

[0115] The substrate processing apparatus 100 described in this embodiment differs from the first, second, or third embodiment in the configuration of the gas supply unit and the plasma generation unit. Fig. 11 is a configuration diagram of the main part of the substrate processing apparatus according to the fourth embodiment.

[0116] In this embodiment, the gas supply pipe 232 constituting the gas supply unit is provided with a remote plasma unit (RPU) 254. The RPU 254 converts the processing gas flowing inside the gas supply pipe 232 into a plasma state.

[0117] That is, the RPU 254 functions as a plasma generating unit (plasma generating mechanism) according to this embodiment. Therefore, in this embodiment, neither the resonance coil 212 described in the first embodiment nor the first coil 212 a and the second coil 212 b described in the third embodiment is provided.

[0118] According to this embodiment having such a configuration, when processing the wafer 200 in the processing chamber 201 , the processing gas supplied from the gas supply pipe 232 into the processing chamber 201 is made into a plasma state by the RPU 254 .

[0119] In this case, it is not necessarily easy to precisely control the plasma energy level, radical amount, and the like in the RPU 254. Therefore, when attempting to ensure a sufficient energy level for processing the wafer 200, the plasma energy may actually be excessive. If gas is supplied into the processing chamber 201 through the gas inlet 234 with such excessive energy, the plasma may attack, for example, a seal member 234a such as an O-ring that seals the connection between the processing vessel 203 and the gas supply pipe 232, which may result in deterioration of the seal member 234a.

[0120] In consideration of this, in this embodiment, an attenuation section 248 is provided on the gas supply pipe 232. More specifically, the attenuation section 248 is provided on the gas supply pipe 232 upstream of the connection between the gas supply pipe 232 and the processing vessel 203 that constitutes the processing chamber 201. The attenuation section 248 may be the same as that in the first, second, or third embodiment.

[0121] The attenuation section 248 may be provided in the flow rate fluctuation section 248g, as in the first, second, or third embodiment. That is, in this embodiment, the flow rate fluctuation section 248g may be provided in the gas supply pipe 232.

[0122] According to the present embodiment having the above-described configuration, the attenuation unit 248 is provided on the gas supply pipe 232 upstream of the connection between the gas supply pipe 232 and the processing vessel 203, thereby attenuating the energy of the processing gas in a plasma state flowing through the gas supply pipe 232. As a result, even if the plasma energy generated by the RPU 254 becomes excessive, for example, by attenuating the plasma energy using the attenuation unit 248, it is possible to suppress deterioration of the apparatus components, particularly deterioration of the seal member 234 a at the connection between the processing vessel 203 and the gas supply pipe 232, caused by the plasma without affecting the atmosphere in the processing chamber 201.

[0123] That is, this embodiment also achieves one or more of the effects described in the first, second or third embodiment, except for the difference between the gas supply unit side and the exhaust unit side.

[0124] <Other Embodiments> Although each embodiment of the present disclosure has been specifically described above, the present disclosure is not limited to the above-described embodiments, and can be used in appropriate combinations, and further, various modifications are possible within the scope of the gist thereof.

[0125] For example, in the above-described embodiments, an oxidation process is performed on the wafer 200 in the substrate processing step. However, the present disclosure is not limited to this. In other words, as long as the process utilizes plasma, it may be a film formation process or a process for forming a film containing a metal, in addition to an oxidation process. In other words, the present disclosure can be suitably applied to other substrate processes, such as an oxidation process, a nitriding process, a film formation process, an annealing process, a diffusion process, and a lithography process. Furthermore, the present disclosure can also be suitably applied to other substrate processing apparatuses, such as an annealing process, an oxidation process, a nitriding process, an exposure apparatus, a coating apparatus, a drying apparatus, a heating apparatus, and a plasma-based processing apparatus. The present disclosure may also incorporate a mixture of these apparatuses. Furthermore, it is possible to replace a portion of the configuration of one embodiment with the configuration of another embodiment, or to add a portion of the configuration of another embodiment to the configuration of another embodiment. Furthermore, it is also possible to add, delete, or replace a portion of the configuration of each embodiment with another configuration.

[0126] Furthermore, the processing gas to be turned into a plasma state is not limited to an O-containing gas and an H-containing gas, and other types of gases can be applied depending on the type of processing to be performed in the substrate processing step.

[0127] REFERENCE SIGNS LIST 100: Substrate processing apparatus 200: Wafer (substrate) 201: Processing chamber 212: Resonance coil 221: Controller 232: Gas supply pipe 231: Gas exhaust pipe 243c: Main valve 246: First pump 248: Attenuation section

Claims

1. A substrate processing apparatus comprising: a processing chamber for processing a substrate with a gas; a plasma generating unit for converting the gas into a plasma state; a supply pipe provided upstream of the processing chamber; an exhaust pipe provided downstream of the processing chamber; a valve provided downstream of the exhaust pipe; and an attenuation unit for attenuating the energy of the gas in the plasma state, the attenuation unit being provided at a position on the exhaust pipe closer to the valve than the processing chamber or being provided upstream of a connection between the supply pipe and the processing chamber.

2. The substrate processing apparatus according to claim 1, wherein the attenuation section is provided in a flow velocity fluctuation section in which the flow velocity of the gas fluctuates.

3. The substrate processing apparatus according to claim 2, wherein the flow velocity varying portion is a portion within the exhaust pipe or the supply pipe where the flow velocity of the gas increases.

4. The substrate processing apparatus according to claim 2, wherein the flow rate varying portion is a piping portion connected to the downstream side of a first pump provided in the gas flow path of the exhaust pipe.

5. The substrate processing apparatus according to claim 2, further comprising, upstream of said flow rate varying portion, a portion where the gas flow direction changes within said supply pipe, or a portion where the gas flow direction changes within said exhaust pipe.

6. The substrate processing apparatus according to claim 1, wherein the valve comprises a valve body and a seal member, and the valve body and the seal member are disposed at positions on an extension line of the supply pipe or the exhaust pipe.

7. The substrate processing apparatus according to claim 6, wherein the sealing member is disposed at a position facing a downstream opening of the supply pipe or the exhaust pipe.

8. The substrate processing apparatus according to claim 6, wherein the diameter of an inlet flow passage constituting said valve is configured to be smaller than the diameter of said supply pipe or said exhaust pipe.

9. The substrate processing apparatus of claim 1, wherein the inside of the exhaust pipe is configured to communicate with the inside of the processing chamber via an exhaust port provided in the processing chamber, and the exhaust pipe further includes a first exhaust pipe connecting a first pump provided in a gas flow path of the exhaust pipe to the exhaust port, and a second exhaust pipe connecting the first pump to the valve, and the damping section is provided in the second exhaust pipe.

10. The substrate processing apparatus according to claim 9, wherein the second exhaust pipe is configured to have a smaller diameter than the first exhaust pipe.

11. The substrate processing apparatus of claim 1, wherein the damping section has at least a first structural section having a plurality of first through holes, and a second structural section provided downstream of the first structural section and having a plurality of second through holes and a gas collision structure provided between the second through holes, and the first through holes and the gas collision wall are arranged to at least partially overlap each other.

12. The substrate processing apparatus according to claim 1, wherein the plasma generating section has a coil capable of generating plasma within the processing chamber.

13. The substrate processing apparatus according to claim 1, wherein the plasma generating section comprises: a first coil capable of generating plasma in the processing chamber; and a second coil adjacent to the first coil and capable of generating plasma in the processing chamber.

14. The substrate processing apparatus according to claim 1, wherein the attenuation section has a gas collision section that collides with the gas flow of the gas.

15. The substrate processing apparatus according to claim 14, wherein the gas collision section has a deactivation section that deactivates the energy of the gas in the plasma state.

16. The substrate processing apparatus according to claim 1, wherein the attenuation section has an inert gas supply section capable of supplying an inert gas to the gas.

17. The substrate processing apparatus according to claim 1, wherein the attenuation section has an ascending section in which the gas flow direction is opposite to the direction of gravity.

18. A substrate processing method for processing a substrate in a processing chamber using a substrate processing apparatus having: a processing chamber for processing a substrate with a gas; a plasma generating unit for converting the gas into a plasma state; a supply pipe provided upstream of the processing chamber; an exhaust pipe provided downstream of the processing chamber; a valve provided downstream of the exhaust pipe; and an attenuation unit for attenuating the energy of the gas in the plasma state, the attenuation unit being provided at a position on the exhaust pipe closer to the valve than the processing chamber or being provided upstream of a connection between the supply pipe and the processing chamber.

19. A method for manufacturing a semiconductor device, comprising the steps of: manufacturing a semiconductor device using the substrate processing method according to claim 18; 20. A program for causing a substrate processing apparatus having a processing chamber for processing a substrate with a gas, a plasma generating unit for turning the gas into a plasma state, a supply pipe provided upstream of the processing chamber, an exhaust pipe provided downstream of the processing chamber, a valve provided downstream of the exhaust pipe, and an attenuation unit for attenuating the energy of the gas in the plasma state, the attenuation unit being provided at a position on the exhaust pipe closer to the valve than the processing chamber or being provided upstream of a connection between the supply pipe and the processing chamber, the program causing the substrate processing apparatus to execute a procedure for processing a substrate in the processing chamber by a computer.

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