Method for manufacturing semiconductor device, substrate processing device, and recording medium

Abstract

The present invention relates to a manufacturing method of a semiconductor device, a substrate processing apparatus, and a recording medium. When a substrate is subjected to a doping process using plasma, generation of deposits is suppressed. In the manufacturing method of a semiconductor device of the present invention, a surface of a substrate is modified into an impurity-containing layer by performing a gas supply process of supplying an impurity-containing gas containing an impurity and a diluent gas into a processing chamber in which the substrate is accommodated, a process of plasma-exciting the impurity-containing gas and the diluent gas, and a process of supplying active species containing the impurity generated by the plasma excitation to the substrate, in the gas supply process, a flow ratio of the impurity-containing gas and the diluent gas is controlled so that a partial pressure of the impurity-containing gas in the processing chamber becomes a predetermined partial pressure which is smaller than a partial pressure at which the impurity-containing gas forms deposits in the processing chamber.

Description

Technical Field

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

[0002] As one of the steps in the manufacturing process of a semiconductor device, there is a treatment in which a film formed on the surface of a substrate is modified by plasma (for example, refer to Patent Document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2017-183487 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] As one of the manufacturing processes of the above-mentioned semiconductor device, for example, a substrate processing process is performed in which boron (B) is injected (doped) into the surface of the substrate as an impurity (dopant) using a boron (B)-containing gas. However, deposits may be generated when B is injected, and the deposits may adhere to the surface of the substrate.

[0008] An object of the present disclosure is to provide a technique capable of suppressing the generation of deposits when performing a doping process on a substrate using plasma.

[0009] Solutions to Problems

[0010] According to one embodiment of the present disclosure, a method for manufacturing a semiconductor device is provided, wherein the surface of a substrate is modified into an impurity-containing layer by performing the following steps: a gas supply step of supplying an impurity-containing gas and a dilution gas containing impurities into a processing chamber accommodating the substrate, a step of plasma-exciting the impurity-containing gas and the dilution gas, and a step of supplying active species containing the impurities generated by the plasma excitation to the substrate, wherein in the gas supply step, the flow ratio of the impurity-containing gas and the dilution gas is controlled so that the partial pressure of the impurity-containing gas in the processing chamber becomes a predetermined partial pressure that is smaller than the partial pressure at which the impurity-containing gas in the processing chamber will form a deposit containing a polymer.

[0011] Effects of the Invention

[0012] According to the present disclosure, it is possible to suppress the generation of deposits when performing a doping process on a substrate using plasma. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 11 is a schematic structural diagram of a substrate processing apparatus 100 preferably used in one embodiment of the present disclosure, and shows a processing furnace 202 portion in a longitudinal cross-sectional view.

[0014] Figure 2 This is a diagram illustrating the principle of plasma generation in one embodiment of the present disclosure.

[0015] Figure 3 This is a schematic configuration diagram of the controller 221 of the substrate processing apparatus 100 preferably used in one embodiment of the present disclosure, and is a diagram showing a control system of the controller 221 in the form of a block diagram.

[0016] Figure 4 The graph shows the measurement results of the water repellency, doping amount, and step coverage of the B-containing layer formed under different conditions.

[0017] Figure 5 middle, Figure 5 (A) is a diagram showing the surface state of a substrate when there is a deposit on the substrate surface. Figure 5 (B) is a diagram showing the surface state of a substrate when there is no deposit on the substrate surface.

[0018] Figure 6 middle, Figure 6 (A) is a graph showing the B concentration in the B-containing layer formed by supplying high-frequency power of 3500 W, 2000 W, and 500 W to the substrate, respectively. Figure 6 (B) is a graph showing the B concentration in the B-containing layer formed when the supply time of the B-containing gas to the substrate is 30 seconds or 60 seconds, respectively. Figure 6 (C) is a graph showing the B concentration in the B-containing layer formed by setting the partial pressure of the B-containing gas to 0.002 Pa, 0.01 Pa, 0.05 Pa, and 0.1 Pa with respect to the substrate.

[0019] Figure 7 middle, Figure 7 (A) is a graph showing the step coverage of the B-containing layer formed when high-frequency power of 3500 W, 2000 W, and 500 W is supplied to the substrate, respectively. Figure 7 (B) is a graph showing the step coverage of the B-containing layer formed when the supply time of the B-containing gas to the substrate is 30 seconds or 60 seconds, respectively. Figure 7 (C) is a graph showing the step coverage of the B-containing layer formed at respective partial pressures of 0.002 Pa, 0.01 Pa, 0.05 Pa, and 0.1 Pa of the B-containing gas on the substrate.

[0020] Explanation of symbols

[0021] 200: Wafer (substrate)

[0022] 203: Processing Containers DETAILED DESCRIPTION

[0023] <One embodiment of the present disclosure>

[0024] Below, refer to Figures 1 to 3 An embodiment of the present disclosure is described below. It should be noted that the drawings used in the following description are schematic diagrams, and the dimensional relationships and ratios of the elements shown in the drawings are not necessarily consistent with actual conditions. Furthermore, the dimensional relationships and ratios of the elements shown in the multiple drawings are not necessarily consistent with each other.

[0025] (1) Substrate processing equipment

[0026] like Figure 1 As shown, substrate processing apparatus 100 includes a processing furnace 202 for accommodating wafers 200 as substrates for plasma processing. Processing furnace 202 includes a processing container 203 that forms a processing chamber 201. Processing container 203 includes a dome-shaped upper container 210 and a bowl-shaped lower container 211. The processing chamber 201 is formed by placing the upper container 210 on the lower container 211.

[0027] A gate valve 244, serving as a loading / unloading port (partition valve), is provided on the lower sidewall of the lower container 211. By opening the gate valve 244, wafers 200 can be loaded into and unloaded from the processing chamber 201 via the loading / unloading port 245. By closing the gate valve 244, the airtightness of the processing chamber 201 can be maintained.

[0028] like Figure 2 As shown, the processing chamber 201 includes a plasma generation space 201a and a substrate processing space 201b communicating with the plasma generation space 201a for processing wafers 200. A resonance coil 212, described later, is provided on the outer periphery of a processing container 203 surrounding the plasma generation space 201a. The plasma generation space 201a is a space where plasma is generated and is located within the processing chamber 201, for example, at a lower end ( Figure 1 On the other hand, the substrate processing space 201 b is a space where the wafer 200 is processed by plasma and is a space below the lower end of the resonance coil 212 .

[0029] A susceptor 217, serving as a substrate mounting portion, is located at the center of the bottom side of the processing chamber 201. A substrate mounting surface 217d is provided on the top surface of the susceptor 217, on which the wafer 200 is mounted. A heater 217b, serving as a heating mechanism, is embedded within the susceptor 217. By supplying power to the heater 217b via a heater power adjustment mechanism 276, the wafer 200 mounted on the substrate mounting surface 217d can be heated to a predetermined temperature within a range of, for example, 25°C to 1000°C.

[0030] The susceptor 217 is electrically insulated from the lower container 211. An impedance adjustment electrode 217c is provided within the susceptor 217. The impedance adjustment electrode 217c is grounded via an impedance variable mechanism 275, which serves as an impedance adjustment unit. By varying the impedance of the impedance variable mechanism 275 within a predetermined range, the potential (bias voltage) of the wafer 200 during plasma processing can be controlled via the impedance adjustment electrode 217c and the susceptor 217.

[0031] A base lifting mechanism 268 is provided below the base 217 to raise and lower the base 217. The base 217 has three through-holes 217a. Three support pins 266, which serve as supports for the wafer 200, are provided on the bottom surface of the lower container 211, corresponding to the three through-holes 217a. When the base 217 is lowered, the tips of the three support pins 266 pass through the corresponding through-holes 217a and protrude above the substrate mounting surface 217d of the base 217. This allows the wafer 200 to be held from below.

[0032] A gas supply showerhead 236 is provided above the processing chamber 201, i.e., above the upper container 210. The gas supply showerhead 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 gas into the processing chamber 201. The buffer chamber 237 functions as a dispersion space for dispersing the gas introduced from the gas inlet 234.

[0033] The downstream ends of gas supply pipe 232a, which supplies a gas containing impurity B such as diborane (B2H6) gas (B-containing gas), gas supply pipe 232b, which supplies a hydrogen (H)-containing gas such as hydrogen (H2) gas, and gas supply pipe 232c, which supplies an oxygen-containing gas such as oxygen (O2) gas (O-containing gas), converge and are connected to gas inlet 234. Gas supply pipe 232a includes, in order from the upstream side of the gas flow, a B-containing gas supply source 250a, a mass flow controller (MFC) 252a serving as a flow control device, and a valve 253a serving as an on-off valve. Gas supply pipe 232b includes, in order from the upstream side of the gas flow, an H-containing gas supply source 250b, an MFC 252b, and a valve 253b. Gas supply pipe 232c includes, in order from the upstream side of the gas flow, an O-containing gas supply source 250c, an MFC 252c, and a valve 253c. A valve 243a is provided downstream of the confluence of the gas supply pipes 232a-232c. By opening and closing valves 253a-253c and 243a, the MFCs 252a-252c can adjust the flow rates while simultaneously supplying B-containing gas, H-containing gas, and O-containing gas into the processing chamber 203. It should be noted that N2 gas, an inert gas, can also be supplied from the gas supply pipes 232a-232c in addition to the various gases described above.

[0034] The B-containing gas is used as an impurity-containing gas, and the H-containing gas is used as a dilution gas. The mixed gas containing the B-containing gas and the H-containing gas is plasma-formed in the substrate processing step described later and supplied to the wafer 200 on which a silicon (Si) film as a film containing silicon (Si) (Si-containing film) is formed, and plays a role in doping the Si film formed on the surface of the wafer 200 with the impurity B, thereby modifying it into a B-containing layer (B-containing film) containing B. The O-containing gas is plasma-formed in the substrate processing step described later and supplied to the wafer 200, and plays a role in modifying (oxidizing) the B-containing layer formed on the surface of the wafer 200. The O-containing gas acts as an oxidant (oxidizing gas) in the substrate processing step described later. The N2 gas is not plasma-formed in the substrate processing step described later and sometimes acts as a purge gas, etc.

[0035] The first supply system (the B-containing gas supply system and the impurity-containing gas supply system) primarily consists of the gas supply showerhead 236 (cover 233, gas inlet 234, buffer chamber 237, opening 238, shielding plate 240, and gas outlet 239), gas supply pipe 232a, MFC 252a, and valves 253a and 243a. The second supply system (the H-containing gas supply system and the dilution gas supply system) primarily consists of the gas supply showerhead 236, gas supply pipe 232b, MFC 252b, and valves 253b and 243a. The third supply system (the O-containing gas supply system and the oxidant supply system) primarily consists of the gas supply showerhead 236, gas supply pipe 232c, MFC 252c, and valves 253c and 243a. It is also possible to incorporate the second gas supply system into the first gas supply system to form the impurity-containing gas supply system.

[0036] An exhaust port 235 for exhausting the inside of the processing chamber 201 is provided on the side wall of the lower container 211. The exhaust port 235 is connected to the upstream end of the exhaust pipe 231. In the exhaust pipe 231, an APC (Auto Pressure Controller) valve 242 as a pressure regulator (pressure regulating unit), a valve 243b, and a vacuum pump 246 as a vacuum exhaust device are provided in sequence from the upstream side. The exhaust system is mainly composed of the exhaust port 235, the exhaust pipe 231, the APC valve 242, and the valve 243b. The vacuum pump 246 may also be included in the exhaust system.

[0037] A helical resonant coil 212 is installed on the outer periphery of the processing chamber 201, that is, outside the sidewall of the upper container 210, so as to surround the processing container 203. The resonant coil 212 is connected to an RF (Radio Frequency) sensor 272, a high-frequency power supply 273, and a frequency integrator (frequency control unit) 274. A shielding plate 223 is installed on the outer periphery of the resonant coil 212.

[0038] High-frequency power supply 273 is configured to supply high-frequency power (RF power) to resonant coil 212. RF sensor 272 is provided on the output side of high-frequency power supply 273. RF sensor 272 is configured to monitor information on the traveling and reflected waves of the high-frequency power supplied from high-frequency power supply 273. Frequency integrator 274 is configured to integrate the frequency of the high-frequency power output from high-frequency power supply 273 based on the information on the reflected waves monitored by RF sensor 272 to minimize the reflected waves.

[0039] Both ends of the resonant coil 212 are electrically grounded. One end of the resonant coil 212 is grounded via a movable slider 213. The other end of the resonant coil 212 is grounded via a fixed ground wire 214. A movable slider 215 is provided between the two ends of the resonant coil 212, allowing for arbitrary positioning of the position at which the resonant coil 212 receives power from the high-frequency power supply 273.

[0040] Shielding plate 223 is configured to not only block leakage of electromagnetic waves to the outside of resonant coil 212 but also to form a capacitance component necessary for constituting a resonant circuit between shielding plate 223 and resonant coil 212 .

[0041] The plasma generating portion (plasma generating means) is mainly composed of the resonance coil 212, the RF sensor 272, and the frequency integrator 274. The high-frequency power supply 273 and the shielding plate 223 may also be included in the plasma generating portion.

[0042] Below, use Figure 2 The operation of the plasma generating unit and the properties of the generated plasma are supplemented.

[0043] The resonant coil 212 is configured to function as a high-frequency inductively coupled plasma (ICP) electrode. The resonant coil 212 is configured to have a winding diameter, winding pitch, number of turns, and other parameters to form a standing wave of a specified wavelength and resonate in a full-wavelength mode. The energized length of the resonant coil 212, i.e., the length of the electrode between the electrodes and the ground, is adjusted to a length that is an integer multiple of the wavelength of the high-frequency power supplied from the high-frequency power supply 273. As an example, the effective cross-sectional area of ​​the resonant coil 212 is 50 to 300 mm. 2 The coil diameter is 200 to 500 mm, and the number of coil turns is 2 to 60. The high-frequency power supplied to resonant coil 212 is 0.5 to 5 kW, preferably 1.0 to 4.0 kW, at a frequency of 800 kHz to 50 MHz. The magnetic field generated by resonant coil 212 is 0.01 to 10 gauss. In this embodiment, as a preferred example, the frequency of the high-frequency power is set to 27.12 MHz, and the current-carrying length of resonant coil 212 is set to one wavelength (approximately 11 meters).

[0044] Frequency integrator 274 receives a voltage signal indicating reflected power from RF sensor 272 and performs correction control to raise or lower the frequency (oscillation frequency) of the high-frequency power output by high-frequency power supply 273 to minimize the reflected power. This correction is performed using a frequency control circuit included in frequency integrator 274. The frequency control circuit is configured to oscillate at the no-load resonant frequency of resonant coil 212 before plasma ignition and, after plasma ignition, at a preset frequency (a frequency obtained by raising or lowering the no-load resonant frequency) that minimizes the reflected power. The frequency control circuit feeds a control signal containing the corrected frequency back to high-frequency power supply 273. Based on this control signal, high-frequency power supply 273 corrects the frequency of the high-frequency power. The frequency of the high-frequency power is optimized to a resonant frequency that minimizes the reflected power in the transmission line.

[0045] With the above configuration, the induction plasma induced within plasma generation space 201a is of high quality, exhibiting little capacitive coupling with the inner walls of processing chamber 201, susceptor 217, and other components. Within plasma generation space 201a, plasma is generated with an extremely low potential and a doughnut-shaped shape when viewed from above. In the example of this embodiment, where the conduction length of resonant coil 212 is one wavelength of the high-frequency power, this doughnut-shaped plasma is generated near a height corresponding to the midpoint of the conduction of the resonant coil.

[0046] like Figure 3 As shown, the controller 221, serving as a control unit, is configured as a computer having a CPU (Central Processing Unit) 221a, RAM (Random Access Memory) 221b, a storage device 221c, and an I / O interface 221d. The RAM 221b, storage device 221c, and I / O interface 221d are configured to exchange data with the CPU 221a via an internal bus 221e. The controller 221 can be connected to input / output devices 225, such as a touch panel, a mouse, a keyboard, and an operation terminal. The controller 221 can also be connected to a display unit, such as a monitor.

[0047] The storage device 221c is comprised of, for example, a flash memory, an HDD (Hard Disk Drive), or a CD-ROM. The storage device 221c stores and reads control programs for controlling the operation of the substrate processing apparatus 100, process recipes describing the substrate processing procedures and conditions, and the like. The process recipes combine the various substrate processing procedures described later so that they are executed by the controller 221 and produce a predetermined result, functioning as a program. The RAM 221b serves as a storage area (work area) for temporarily storing programs and data read by the CPU 221a.

[0048] The I / O interface 221d is connected to the above-mentioned MFC252a~252c, valves 253a~253c, 243a, 243b, gate valve 244, APC valve 242, vacuum pump 246, heater 217b, RF sensor 272, high-frequency power supply 273, frequency integrator 274, base lifting mechanism 268, impedance variable mechanism 275, etc.

[0049] The CPU 221a is configured to read out the control program from the storage device 221c and execute it, and at the same time read out the process recipe from the storage device 221c in response to the input of the operation instruction from the input / output device 225. Figure 1 As shown, the CPU 221a is further configured to control the opening adjustment action of the APC valve 242, the switching action of the valve 243b, and the start and stop of the vacuum pump 246 through the I / O interface 221d and the signal line A according to the content of the read process recipe, control the lifting action of the base lifting mechanism 268 through the signal line B, control the supply power adjustment action (temperature adjustment action) of the heater power adjustment mechanism 276 to the heater 217b based on the temperature sensor and the impedance value adjustment action by the impedance variable mechanism 275 through the signal line C, control the switching action of the gate valve 244 through the signal line D, control the actions of the RF sensor 272, the frequency integrator 274 and the high-frequency power supply 273 through the signal line E, and control the flow adjustment action of various gases and the switching action of the valves 253a to 253c and 243a by the MFCs 252a to 252c through the signal line F.

[0050] (2) Substrate processing

[0051] Using the aforementioned substrate processing apparatus 100, an example substrate processing flow will be described for doping the surface of a wafer 200 with boron (B), an example impurity, to form a B-containing layer, and then forming an oxide layer as a cap layer on the surface of the doped B-containing layer, as one step in the semiconductor device manufacturing process. In the following description, the operation of each component of the substrate processing apparatus 100 is controlled by the controller 221.

[0052] In the substrate processing flow of this method, a B-containing layer is formed as an impurity-containing layer on the surface of the wafer by performing the following steps: a gas supply step of supplying a B-containing gas as an impurity-containing gas and an H-containing gas as a dilution gas into a processing chamber 201 that accommodates the substrate, a step of plasma-exciting a mixed gas of the B-containing gas and the H-containing gas, and a step of supplying an active species containing B as an impurity generated by the plasma excitation to the wafer 200. In the gas supply step, the flow ratio of the B-containing gas and the H-containing gas is controlled so that the partial pressure of the B-containing gas in the processing chamber 201 becomes a predetermined partial pressure that is smaller than the partial pressure of the B-containing gas in the processing chamber 201 at which a deposit containing a polymer (polymer) is formed.

[0053] Furthermore, in the substrate processing flow of this method, after a B-containing layer is formed as an impurity-containing layer on the surface of the wafer, an oxide layer is formed on the surface of the B-containing layer by performing a process of plasma-exciting an O-containing gas and a process of supplying active species containing oxygen (O) generated by the plasma excitation to the wafer surface.

[0054] In this specification, when the term "wafer" is used, it includes the case where it means "the wafer itself" and the case where it means "a stack of a wafer and a predetermined layer, film, etc. formed on its surface." When the term "wafer surface" is used in this specification, it includes the case where it means "the surface of the wafer itself" and the case where it means "the surface of a predetermined layer, etc. formed on the wafer." In this specification, when it is stated that "a predetermined layer is formed on the wafer," it includes the meaning of directly forming a predetermined layer on the surface of the wafer itself and the meaning of forming a predetermined layer on a layer formed on the wafer, etc. When the term "substrate" is used in this specification, it has the same meaning as when the term "wafer" is used.

[0055] (Wafer loading)

[0056] With the susceptor 217 lowered to the predetermined transfer position, the gate valve 244 is opened, and the wafer 200 to be processed is loaded into the processing container 203 by a transfer robot (not shown). The wafer 200 loaded into the processing container 203 is supported in a horizontal position on three support pins 266 protruding upward from the substrate mounting surface 217d of the susceptor 217. After the wafer 200 is loaded into the processing container 203, the arm of the transfer robot is withdrawn from the processing container 203, and the gate valve 244 is closed. The susceptor 217 is then raised to the predetermined processing position, and the wafer 200 to be processed is transferred from the support pins 266 to the susceptor 217.

[0057] A high-aspect-ratio structure having an aspect ratio of 20 or greater is formed on the surface of wafer 200, the target of processing. A silicon (Si) film, which is a silicon-containing film and is the target of modification, is pre-formed on the surface of wafer 200, including the inner surface of the high-aspect-ratio structure. The high-aspect-ratio structure includes, for example, groove structures such as trenches and cylindrical structures such as post holes. Hereinafter, the term "wafer surface" includes surfaces such as the inner side surfaces and bottom surface of the high-aspect-ratio structure formed on wafer 200.

[0058] (Pressure adjustment, temperature adjustment)

[0059] Next, vacuum pump 246 evacuates the processing container 203 to the desired processing pressure. The pressure within the processing container 203 is measured by a pressure sensor, and feedback control of the APC valve 242 is performed based on this pressure information. Heater 217b heats the wafers 200 to the desired processing temperature. Once the processing container 203 reaches the desired processing pressure and the wafers 200 reach the desired processing temperature, the doping process, described below, begins.

[0060] (Doping treatment)

[0061] B2H6 gas (B-containing gas) and H2 gas (H-containing gas) are supplied into the processing chamber 203 and excited into plasma, generating active species containing B and H. Specifically, valves 253a and 253b are opened, and the flow rates are adjusted by MFCs 252a and 252b. The B-containing gas and the H-containing gas are mixed and supplied into the processing chamber 201 through the gas inlet 234, the buffer chamber 237, and the gas outlet 239. At this time, high-frequency power is supplied from the high-frequency power supply 273 to the resonant coil 212. As a result, an induction plasma, shaped like a donut when viewed from above, is excited within the plasma generation space 201a at a height corresponding to the midpoint of the energization of the resonant coil 212.

[0062] The B-containing gas and H-containing gas contained in the mixed gas are activated (excited) by the excitation of the induction plasma and react to generate active species containing B in the processing container 203. The active species containing B include excited B atoms (B ＊ ), ionized B atoms and B radicals. In addition, the H-containing gas contained in the mixed gas is also activated by the excitation of the induced plasma, etc., and H active species are generated in the processing container 203. The H active species include excited H atoms (H ＊ ), at least any one of ionized H atoms and H radicals.

[0063] The generated active species containing B are then supplied to the wafer 200 together with the active species containing H. As a result, the Si film previously formed on the surface of the wafer 200 is modified. In this way, B is implanted as an impurity into the Si film to be modified, forming a B-containing layer on the surface of the wafer 200.

[0064] That is, the B-containing gas and the H-containing gas supplied into the processing chamber 201 as impurity-containing gases are plasma-excited, and the active species containing the impurity B generated by the plasma excitation are supplied to the surface of the wafer 200, thereby forming a B-containing layer as an impurity-containing layer on the surface of the wafer 200.

[0065] The treatment conditions in this step are exemplified below:

[0066] B2H6 gas supply flow rate: 1 to 100 sccm, preferably 2 to 10 sccm,

[0067] H2 gas supply flow rate: 100-3000 sccm, preferably 1000-2000 sccm,

[0068] Each gas supply time: 1 to 300 seconds, preferably 10 to 60 seconds,

[0069] High frequency power: 100-5000W, preferably 500-3500W,

[0070] Processing temperature: room temperature to 900°C, preferably 500 to 700°C,

[0071] Processing pressure: 5-150 Pa, more preferably 30-150 Pa,

[0072] The distance from the plasma generation space to the substrate surface is 10 to 150 mm, preferably 30 to 100 mm.

[0073] Note that in this embodiment, the B-containing gas supplied from the B-containing gas supply system is B₂H₆ gas diluted to 2% with H₂ gas. In other words, the supply flow rate of B₂H₆ gas in the aforementioned processing conditions represents the supply flow rate of the B-containing gas diluted to 2% with H₂ gas.

[0074] In particular, by setting the processing pressure to 30 Pa or more, it is possible to suppress the occurrence of sputtering on the inner wall of the processing container 203 under the present processing conditions.

[0075] It should be noted that the aforementioned “distance from the plasma generation space to the substrate surface” refers to the distance from the lower end position of the resonance coil 212 to the surface of the wafer 200 .

[0076] In this specification, the numerical range of “1 to 100 sccm” means “1 sccm or more and 100 sccm or less.” The same applies to other numerical ranges.

[0077] Here, the partial pressure of the B-containing gas relative to the total pressure of the mixed gas (B-containing gas, H-containing gas) within the processing chamber 201 is set to a predetermined partial pressure lower than the partial pressure of the B-containing gas within the processing chamber 201 at which deposits containing polymers (multimers) are formed (i.e., a predetermined partial pressure within the range below which deposits containing impurity B do not accumulate), for example, to be 0.01 Pa or less, preferably 0.002 Pa or less. Specifically, the partial pressure of the B-containing gas relative to the total pressure of the mixed gas within the processing chamber 201 is adjusted to the predetermined partial pressure by separately controlling MFC 252a in the B-containing gas supply system (impurity-containing gas supply system) and MFC 252b in the H-containing gas supply system (dilution gas supply system). Thus, during the doping process, by setting the partial pressure of the B-containing gas relative to the total pressure within the processing chamber to 0.01 Pa or less, the formation of B-containing deposits can be suppressed. Setting it to 0.002 Pa or less further suppresses the formation of B-containing deposits. If the partial pressure exceeds 0.01 Pa, the surface roughness will be significantly increased due to the deposits containing B attached to the substrate surface, which may reduce the device characteristics. In addition, the attached deposits may have adverse effects such as reducing the uniformity of other substrate processing after the doping process (such as film formation processing, etc.).

[0078] It should be noted that the partial pressure of the B-containing gas can be adjusted by controlling the exhaust system to adjust the total pressure of the gas in the processing chamber 201. However, if the total pressure in the processing chamber 201 is lowered (for example, to less than 30 Pa) to reduce the partial pressure of the B-containing gas, sputtering is likely to occur on the inner wall of the processing container 203. Therefore, it is preferable to adjust the partial pressure of the B-containing gas by controlling the supply flow ratio with the H-containing gas used as a dilution gas.

[0079] The deposit containing B as an impurity contains at least a polymer (polymer) of the B-containing gas as an impurity gas. In particular, B2H6 as a B-containing gas easily forms decaborane (B 10 H 14) and other polymers (polymers), the higher the partial pressure (concentration), the easier it is to form a polymer. If a polymer is generated, the polymer will accumulate on the surface of the membrane and form a deposit. In addition, in addition to the polymer, the impurity B monomer is sometimes not doped into the membrane and remains on the surface of the membrane to form a deposit. By setting the partial pressure of the B-containing gas relative to the total pressure of the impurity-containing gas in the doping treatment to below 0.01Pa as described above, it is difficult to generate a polymer containing B. By setting it to below 0.002Pa, it is even more difficult to generate a polymer containing B, and the generation of deposits containing B is suppressed. However, if the partial pressure of the B-containing gas is less than 0.0001Pa, it is difficult for B to be substantially doped on the membrane surface. By making the partial pressure of the B-containing gas above 0.0001Pa, B can be doped into the membrane surface at a practical speed.

[0080] Then, after a predetermined time has passed and a predetermined amount of B has been implanted into the wafer 200 , the power supply from the high frequency power supply 273 is stopped, and at the same time, the valves 253 a and 253 b are closed to stop the supply of B-containing gas and H-containing gas into the processing chamber 201 .

[0081] Furthermore, the B-containing active species generated by plasma excitation are isotropic and uniformly supplied to the surface of wafer 200, thereby conformally forming a B-containing layer as an impurity-containing layer on the inner surface of wafer 200 having a high aspect ratio structure with an aspect ratio of 20 or greater. The step coverage of the formed B-containing layer is 70% or greater, preferably 80% or greater.

[0082] Here, by adjusting the magnitude of the high-frequency power for plasma excitation of the impurity-containing gas (B-containing gas) and the dilution gas (H-containing gas) during the doping process, the supply time of the impurity-containing gas and the dilution gas, or at least any one of the partial pressures of the impurity-containing gas, the step coverage of the B-containing layer formed on the wafer surface can be controlled to be above a predetermined value.

[0083] Specifically, during the doping process, by reducing the magnitude of the high-frequency power for plasma excitation of the B-containing gas and the H-containing gas, the step coverage of the B-containing layer can be increased. By making the magnitude of the high-frequency power below a predetermined power value, the step coverage of the B-containing layer can be adjusted to above a predetermined value.

[0084] In addition, during the doping process, by extending the supply time of the B-containing gas and the H-containing gas, the step coverage of the B-containing layer can be increased. By making the supply time longer than a predetermined time, the step coverage of the B-containing layer can be adjusted to be higher than a predetermined value.

[0085] (Oxidation treatment)

[0086] Next, O2 gas as the O-containing gas is supplied into the processing vessel 203 and plasma excitation is performed to generate active species of O. Specifically, the valve 253c is opened, the flow rate is adjusted by the MFC 252c, and at the same time, the O2 gas is supplied into the processing chamber 201 via the gas introduction port 234, the buffer chamber 237, and the gas blow-out port 239. At this time, high-frequency power is supplied to the resonance coil 212 from the high-frequency power source 273. As a result, an inductively coupled plasma in the shape of a doughnut in plan view is excited at a position in the plasma generation space 201a at a height corresponding to the center point of the energization of the resonance coil 212.

[0087] The O2 gas is activated (excited) by excitation of the inductively coupled plasma and the like and reacts to generate active species of O in the processing vessel 203. The active species of O include at least any one of O atoms (O ＊ ) in an excited state, ionized O atoms, and O radicals.

[0088] Then, the generated active species of O is supplied to the wafer 200. As a result, by the above-described doping treatment, the surface of the B-containing layer formed on the surface of the wafer 200 is oxidized to form an oxide layer.

[0089] That is, after the B-containing layer as the impurity-containing layer is formed on the surface of the wafer, the active species of O generated by plasma excitation is supplied to the surface of the wafer 200 by plasma excitation of the O2 gas as the O-containing gas supplied into the processing chamber 201, so that an oxide layer (cap layer) is formed on the surface of the B-containing layer as the impurity-containing layer. As a result, the impurity B can be inhibited from being desorbed from the B-containing layer as the impurity-containing layer, and a high B concentration in the B-containing layer can be maintained.

[0090] As the processing conditions in this process, the following are exemplified:

[0091] O2 gas supply flow rate: 100 to 2000 seem,

[0092] O2 gas supply time: 10 to 60 seconds, preferably 10 to 30 seconds,

[0093] High-frequency power: 100 to 5000 W, preferably 500 to 3500 W,

[0094] Processing temperature: room temperature to 900°C, preferably 500 to 700°C,

[0095] Processing pressure: 5 to 100 Pa, more preferably 30 to 100 Pa,

[0096] Distance from the plasma generation space to the surface of the substrate: 10 to 150 mm, preferably 30 to 100 mm.

[0097] Through this oxidation process, an oxide layer is conformally formed on the inner surface of the wafer 200 having a high aspect ratio structure with an aspect ratio of 20 or greater. Here, the step coverage of the formed oxide layer is greater than 70%, preferably greater than 80%. In particular, in this embodiment, since the adhesion of deposits containing B to the inner surface of the high aspect ratio structure is suppressed during the doping process, a decrease in the step coverage of the oxide layer (a decrease in uniformity) caused by the adhesion of the deposits can be prevented.

[0098] It should be noted that, according to this oxidation treatment, by supplying active species containing O to the surface of the wafer 200, the deposits attached to the surface of the wafer 200 can be further removed. That is, even when a small amount of deposits are attached to the surface of the wafer 200, the deposits can be removed by performing this oxidation treatment. However, when removing the deposits by this oxidation treatment, since the oxidation treatment must be performed until the deposits are removed, it is necessary to extend the time for the oxidation treatment compared to the case where no deposits are attached. As a result, sometimes the oxide layer will reach a thickness greater than necessary. In addition, due to the oxidation treatment, part of the impurity B will be detached from the B-containing layer, and sometimes the B concentration will be reduced. Therefore, even in the case of performing this oxidation treatment, it is desirable to perform a doping treatment as in the present embodiment to suppress the attachment of the deposits to the surface of the wafer 200.

[0099] (Post-purge and atmospheric pressure recovery)

[0100] After the oxidation process is completed, the supply of O2 gas into the processing container 203 is stopped, and the supply of high-frequency power to the resonant coil 212 is stopped. Then, N2 gas is supplied into the processing container 203 as a purge gas and exhausted through the exhaust pipe 231. This purges the processing container 203, removing any remaining gas and reaction byproducts. The atmosphere in the processing container 203 is then replaced with N2 gas, and the pressure in the processing container 203 is restored to normal pressure.

[0101] (Wafer removal)

[0102] Next, the susceptor 217 is lowered to a predetermined transfer position, and the wafer 200 is transferred from the susceptor 217 to the support pins 266. Then, the gate valve 244 is opened, and a transfer robot (not shown) is used to move the processed wafer 200 out of the processing container 203. This completes the substrate processing step of this embodiment.

[0103] (3) According to the effect of this method

[0104] According to this aspect, one or more of the following effects are obtained.

[0105] (a) By performing the above-described doping treatment, the generation of and the adhesion of the deposit containing the impurity (B) to the wafer are suppressed. Therefore, a process for removing the deposit is not required or the time for removal can be shortened. As a result, the throughput can be improved. In addition, when the O2 plasma treatment (oxidation treatment) is performed after the doping treatment, the deposit is not required to be removed or the time for removal can be shortened, so that the time for the O2 plasma treatment can be shortened, the increase in the thickness of the oxide layer is suppressed, and the high impurity concentration in the impurity-containing layer is maintained.

[0106] (b) The adhesion of the deposit in the processing vessel 203 can be suppressed, and the frequency of maintenance of the substrate in the processing vessel 203 can be reduced.

[0107] (c) By adjusting at least any one of the magnitude of the high-frequency power in the above-described doping treatment or the supply time of the impurity-containing gas or the partial pressure of the impurity-containing gas, the step coverage of the impurity-containing layer in the high aspect ratio structure can be controlled to be equal to or more than a predetermined value.

[0108] (d) After the above-described doping treatment, by performing the oxidation treatment, the step coverage of the cap layer (oxide layer) formed on the impurity-containing layer can be improved. That is, by suppressing the generation of the deposit in the doping treatment, the decrease in the step coverage and the increase in the cap layer due to the deposit in the oxidation treatment after the doping treatment can be suppressed. Further, by suppressing the increase in the cap layer, as a result, the high impurity concentration can be maintained.

[0109] (e) In addition, after the above-described doping treatment, by performing the oxidation treatment, even when a small amount of the deposit is deposited, the deposited deposit can be removed.

[0110] (f) When a gas containing an impurity other than the B-containing gas, which forms a deposit containing a polymer in the processing chamber, is used, or when an O-containing gas other than the O2 gas is used, the above-described effects can also be obtained.

[0111] Note that, in the doping treatment of the above-described embodiment, the case where B2H6 gas is used as the B-containing gas is described, but the present disclosure is not limited thereto, and, as the impurity-containing gas, a gas including at least any one of boron trichloride (BC13) gas and boron trifluoride (BF3) gas, for example, can be used. In this case, the same effects as the above-described substrate processing flow can also be obtained.

[0112] In addition, in the above-described embodiment, the case where B is used as the impurity is described, but the present disclosure is not limited thereto, and, as the impurity, at least any one of arsenic (As), phosphorus (P), and gallium (Ga), for example, can be used. In this case, the same effects as the above-described substrate processing flow can also be obtained.

[0113] In addition, in the above embodiment, a case where a gas containing H is used as a dilution gas is described, but the present disclosure is not limited thereto, and an inert gas such as helium (He), argon (Ar), neon (Ne), krypton (Kr), or xenon (Xe) may be used. In this case, the same effects as those of the above substrate processing flow can be achieved.

[0114] In addition, in the oxidation process of the above embodiment, the case of using O2 gas as the O-containing gas has been described, but the present disclosure is not limited to this. In addition to O2 gas, other O-containing gases, such as ozone (O3) gas, water vapor (H2O gas), and nitric oxide (NO) gas, can be used. In this case, the same effects as those of the above substrate processing flow can be achieved.

[0115] In addition, in the above embodiment, as the object of modification, the case of using a wafer with a Si film formed on the surface is described, but the present disclosure is not limited to this. As the object of modification, in addition to the Si film, other silicon-containing films such as silicon oxide (SiO) film, silicon nitride (SiN) film, silicon oxynitride (SiON) film, Si-containing base composed of Si substrate, and films containing metal elements as other films containing elements other than Si can be used. In addition, the Si film as the object of modification can be a film composed of amorphous silicon (a-Si), single crystal silicon (c-Si), polycrystalline silicon (Poly-Si), etc. In addition, the object of modification can also be a multi-layer film (layer) such as a Si film and a SiO film formed on its upper surface. In these cases, the same effect as the above-mentioned substrate processing flow can be obtained.

[0116] <Other methods>

[0117] While the embodiments of the present disclosure have been specifically described above, the present disclosure is not limited to the above embodiments and various modifications can be made without departing from the spirit of the present disclosure.

[0118] Example 1

[0119] Wafer samples 1 to 7 with Si films formed on their surfaces were prepared. Samples 1 to 7 were Figure 4 The doping treatment was performed under the conditions shown in the figure, and the water repellency of the wafer surface and the distribution of the B dopant dose in the depth direction after the doping treatment were evaluated. It should be noted that a SiO layer as a natural oxide film was formed on the surface of these samples.

[0120] For Sample 1, the doping treatment was performed at a process temperature of 700°C, a high-frequency power of 3500W, a process pressure (total pressure) of 100Pa, a partial pressure of 0.002Pa for B2H6 gas (B-containing gas), and a supply time of 30 seconds for B2H6 gas and H2 gas. The supply flow rate of B2H6 gas diluted to 2% with H2 gas (2% B2H6 gas) was 2sccm, and the supply flow rate of H2 gas was 1998sccm. The flow ratio of B2H6 gas to H2 gas supplied into the process chamber was set to 1:50,000, resulting in a partial pressure of 0.002Pa for the B-containing gas.

[0121] For Sample 2, the doping treatment was performed at a high-frequency power of 2000 W. The other treatment conditions were the same as those for Sample 1 described above.

[0122] Sample 3 was doped at a high-frequency power of 500 W. Other treatment conditions were the same as those for Sample 1 described above.

[0123] For Sample 4, the doping treatment was performed with the supply time of the B-containing gas and the H-containing gas being 60 seconds. The other treatment conditions were the same as those for Sample 1 described above.

[0124] For Sample 5, the doping treatment was performed with a B-containing gas partial pressure of 0.01 Pa. The supply flow rate of 2% B2H6 gas was 10 sccm, and the supply flow rate of H2 gas was 1990 sccm. The flow rate ratio of B2H6 gas to H2 gas supplied into the process chamber was set to 1:10000, resulting in a B-containing gas partial pressure of 0.01 Pa. Other processing conditions were the same as those for Sample 1.

[0125] For Sample 6, the doping treatment was performed with a B-containing gas partial pressure of 0.05 Pa. The 2% B₂H₆ gas was supplied at a flow rate of 50 sccm, and the H₂ gas was supplied at a flow rate of 1950 sccm. The flow rate ratio of B₂H₆ to H₂ gas supplied into the process chamber was set at 1:2000, resulting in a B-containing gas partial pressure of 0.05 Pa. Other processing conditions were the same as those for Sample 1.

[0126] For Sample 7, the doping treatment was performed with a B-containing gas partial pressure of 0.1 Pa. The supply flow rate of 2% B2H6 gas was 100 sccm, and the supply flow rate of H2 gas was 1900 sccm. The flow rate ratio of B2H6 gas to H2 gas supplied into the process chamber was set to 1:1000, resulting in a B-containing gas partial pressure of 0.01 Pa. Other processing conditions were the same as those for Sample 1.

[0127] Then, the doped samples 1 to 7 were cleaned with a 1% hydrogen fluoride (HF) aqueous solution for 30 seconds, and the surface conditions after cleaning were compared. Figure 5 When the surface state shows hydrophilicity as shown in (A), it is recorded as "no" water repellency. Figure 5 If the surface condition shows water repellency as shown in (B), it is recorded as "water repellency". It should be noted that when there is no deposit on the surface, water repellency is also shown after the natural oxide film is removed by HF. When there is deposit on the surface, water repellency is not shown after the natural oxide film is removed by HF, and hydrophilicity is shown.

[0128] like Figure 4 As shown, when the partial pressure of the B-containing gas was 0.002 Pa for Samples 1 to 4 and 0.01 Pa for Sample 5, water repellency was exhibited, and adhesion of deposits to the surface was confirmed to be sufficiently suppressed. When the partial pressure of the B-containing gas was 0.05 Pa for Sample 6 and 0.1 Pa for Sample 7, water repellency was not exhibited, and deposits were confirmed to be present on the surface.

[0129] That is, it was confirmed that by setting the partial pressure of the B-containing gas in the doping process to 0.01 Pa or less, preferably 0.002 Pa or less, the generation of deposits can be suppressed, and the adhesion of deposits to the wafer can be suppressed.

[0130] Next, the depth-wise concentration (atoms / cm2) of B contained in the B-containing layers formed in each of Samples 1 to 7 was measured using Secondary Ion Mass Spectrometry (SIMS). 3 ) distribution for analysis.

[0131] Figure 6 (A) shows the SIMS analysis results of B contained in the B-containing layers formed in Samples 1 to 3, respectively, in the depth direction from the wafer surface.

[0132] like Figure 6 As shown in (A), at a depth of 5 nm, the dopant dose in the B-containing layer formed by supplying 3500 W of high-frequency power in Sample 1 is higher than that in the B-containing layer formed by supplying 2000 W of high-frequency power in Sample 2. Furthermore, the dopant dose in the B-containing layer formed by supplying 2000 W of high-frequency power in Sample 2 is higher than that in the B-containing layer formed by supplying 500 W of high-frequency power in Sample 3. This confirms that the dopant dose depends on the magnitude of the high-frequency power and can be controlled by the magnitude of the high-frequency power.

[0133] Figure 6 (B) shows the SIMS analysis results of B contained in the B-containing layers formed in Sample 1 and Sample 4, respectively, in the depth direction from the wafer surface.

[0134] like Figure 6 As shown in (B), at a depth of 5 nm, the dopant dose in the B-containing layer formed in Sample 4, which was formed by supplying the B-containing gas and H-containing gas mixture for 60 seconds, was higher than that in Sample 1, which was formed by supplying the B-containing gas and H-containing gas mixture for 30 seconds. This confirms that the dopant dose depends on the supply time of the B-containing gas and H-containing gas mixture, and that the dopant dose can be controlled by supplying the B-containing gas and H-containing gas mixture.

[0135] Figure 6 (C) shows the SIMS analysis results of B contained in the B-containing layers formed in Sample 1 and Samples 5 to 7, respectively, in the depth direction from the wafer surface.

[0136] like Figure 6 As shown in (C), at a depth of 5 nm, the dopant dose of the B-containing layer formed at a B-containing gas partial pressure of 0.002 Pa in Sample 1 is increased compared to the B-containing layer formed at a B-containing gas partial pressure of 0.01 Pa in Sample 5. Furthermore, the dopant dose of the B-containing layer formed at a B-containing gas partial pressure of 0.05 Pa in Sample 6 is increased compared to the B-containing layer formed at a B-containing gas partial pressure of 0.002 Pa in Sample 1. Furthermore, the dopant dose of the B-containing layer formed at a B-containing gas partial pressure of 0.1 Pa in Sample 7 is increased compared to the B-containing layer formed at a B-containing gas partial pressure of 0.05 Pa in Sample 6. In other words, it was confirmed that the dopant dose depends on the B-containing gas partial pressure and that the dopant dose can be controlled by the B-containing gas partial pressure.

[0137] Next, wafer samples 1' to 7' were prepared, each having a groove structure with a depth of about 3.5 nm and a Si film formed on the surface. Samples 1' to 7' were processed in the same manner as samples 1 to 7. Figure 4 The doping treatment was carried out under the conditions shown, and the step coverage (layer thickness uniformity) of the B-containing layer on the inner surface of the groove structure was evaluated.

[0138] The B concentration (atoms / cm 3 ) is set to C top , set the concentration of B near 3.5nm to C btm When 100×C btm / C top Calculate the step coverage.

[0139] Figure 7 (A) shows the SIMS analysis results of B contained in the B-containing layers formed in Samples 1' to 3', respectively, in the depth direction from the wafer surface.

[0140] The step coverage of the B-containing layer formed in Sample 1', when supplied with 3500W of high-frequency power, was 26%. The step coverage of the B-containing layer formed in Sample 2', when supplied with 2000W of high-frequency power, was 73%. The step coverage of the B-containing layer formed in Sample 3', when supplied with 500W of high-frequency power, was 81%. This confirms that reducing the level of high-frequency power during the doping process can improve step coverage. In other words, it was confirmed that step coverage depends on the level of high-frequency power and can be controlled by the high-frequency power.

[0141] Figure 7 (B) shows the SIMS analysis results of B contained in the B-containing layers formed in Sample 1' and Sample 4', respectively, in the depth direction from the wafer surface.

[0142] The step coverage of the B-containing layer formed by supplying the B-containing gas and H-containing gas mixture for 30 seconds in Sample 1' was 26%. The step coverage of the B-containing layer formed by supplying the B-containing gas and H-containing gas mixture for 60 seconds in Sample 4' was 53%. This confirms that increasing the supply time of the B-containing gas and H-containing gas mixture during the doping process improves the step coverage. In other words, it was confirmed that the step coverage depends on the supply time of the B-containing gas and H-containing gas mixture and can be controlled by adjusting the supply time of the B-containing gas and H-containing gas mixture.

[0143] Figure 7 (C) shows the SIMS analysis results of B contained in the B-containing layers formed in Sample 1' and Samples 5' to 7', respectively, in the depth direction from the wafer surface.

[0144] The step coverage of the B-containing layer of Sample 1', formed at a B-containing gas partial pressure of 0.002 Pa, was 26%. The step coverage of the B-containing layer of Sample 5', formed at a B-containing gas partial pressure of 0.01 Pa, was 49%. The step coverage of the B-containing layer of Sample 6', formed at a B-containing gas partial pressure of 0.05 Pa, was 87%. The step coverage of the B-containing layer of Sample 7, formed at a B-containing gas partial pressure of 0.1 Pa, was 63%. This confirms that the step coverage depends on the B-containing gas partial pressure and can be controlled by the B-containing gas partial pressure.

[0145] That is, it was confirmed that the doping dose and step coverage of the B-containing layer injected with B as an impurity depend on the power value of the high-frequency power in the doping process, the supply time of the mixed gas of B-containing gas and H-containing gas, and the partial pressure of the B-containing gas, and can be controlled by the power value of the high-frequency power in the doping process, the supply time of the B-containing gas and H-containing gas, and the partial pressure of the B-containing gas.

Claims

1. A method for manufacturing a semiconductor device, The impurity-containing layer is conformally formed on the inner surface of the high aspect ratio structure by performing the following steps: A gas supply step of supplying an impurity-containing gas and a hydrogen gas containing impurities into a processing chamber accommodating a substrate having a high aspect ratio structure with an aspect ratio of 20 or more, a step of plasma exciting the impurity-containing gas and the hydrogen gas, and supplying active species containing the impurities generated by plasma excitation to the substrate; In the gas supply step, the flow rate ratio of the impurity-containing gas and the hydrogen gas is controlled so that the partial pressure of the impurity-containing gas in the processing chamber becomes a predetermined partial pressure lower than the partial pressure at which the impurity-containing gas forms deposits containing polymers in the processing chamber.

2. The method for manufacturing a semiconductor device according to claim 1, wherein: The predetermined partial pressure is 0.01 Pa or less.

3. The method for manufacturing a semiconductor device according to claim 1, wherein: The predetermined partial pressure is 0.002 Pa or less.

4. The method for manufacturing a semiconductor device according to claim 1, wherein The impurity is at least any one of boron, arsenic, phosphorus, and gallium.

5. The method for manufacturing a semiconductor device according to claim 1, wherein: The impurity-containing gas includes at least any one selected from the group consisting of diborane gas, boron trichloride gas, and boron trifluoride gas.

6. The method for manufacturing a semiconductor device according to claim 1, wherein: The surface of the substrate is composed of at least one of a silicon-containing film and a silicon-containing base.

7. The method for manufacturing a semiconductor device according to claim 6, wherein: The surface of the substrate is formed of at least any one selected from the group consisting of a silicon oxide film, a silicon nitride film, and a silicon oxynitride film.

8. The method for manufacturing a semiconductor device according to claim 1, wherein: In the plasma excitation step, the step coverage of the impurity-containing layer formed on the surface of the substrate is controlled by adjusting the magnitude of the high-frequency power for plasma excitation.

9. The method for manufacturing a semiconductor device according to claim 8, wherein: In the step of exciting the plasma, adjustment is performed so that the step coverage of the impurity-containing layer is increased by reducing the magnitude of the high-frequency power.

10. The method for manufacturing a semiconductor device according to claim 1 or 2, wherein: After the impurity-containing layer is formed on the surface of the substrate, the surface of the impurity-containing layer is modified into an oxide layer by performing the following steps: a step of plasma exciting an oxygen-containing gas, and A step of supplying active species containing oxygen generated by plasma excitation to the surface of the substrate.

11. The method for manufacturing a semiconductor device according to claim 10, wherein: The oxide layer is conformally formed on the inner surface of the high aspect ratio structure.

12. The method for manufacturing a semiconductor device according to claim 11, wherein: The step coverage of the oxide layer formed on the inner surface of the high aspect ratio structure is greater than 70%.

13. The method for manufacturing a semiconductor device according to claim 1, wherein: The step coverage of the impurity-containing layer formed on the inner surface of the high-aspect ratio structure is greater than 70%.

14. A substrate processing apparatus comprising: A processing chamber for accommodating a substrate having a high aspect ratio structure with an aspect ratio of 20 or more, a gas supply system for supplying an impurity-containing gas and hydrogen gas into the processing chamber; an exhaust system for exhausting the processing chamber, a plasma generating portion for exciting the impurity-containing gas and the hydrogen gas supplied into the processing chamber into plasma, and A control unit is configured to control the gas supply system, the exhaust system, and the plasma generating unit to perform the following processing: a process of conformally forming an impurity-containing layer on the inner surface of the high-aspect-ratio structure by performing a gas supply process of supplying the impurity-containing gas and the hydrogen gas into the processing chamber, a process of plasma-exciting the impurity-containing gas and the hydrogen gas, and a process of supplying active species containing the impurities generated by the plasma excitation to the substrate, wherein in the gas supply process, a flow rate ratio of the impurity-containing gas and the hydrogen gas can be controlled so that the partial pressure of the impurity-containing gas in the processing chamber becomes a predetermined partial pressure that is lower than the partial pressure at which the impurity-containing gas in the processing chamber will form a deposit containing a polymer.

15. A computer-readable recording medium having a program recorded thereon for causing a substrate processing apparatus to execute, via a computer, a process of conformally forming an impurity-containing layer on an inner surface of a high-aspect-ratio structure by performing the following process: A process of supplying an impurity-containing gas and a hydrogen gas containing impurities into a processing chamber accommodating a substrate having a high aspect ratio structure with an aspect ratio of 20 or more, a process of exciting the impurity-containing gas and the hydrogen gas into a plasma, and a process of supplying active species containing the impurities generated by the plasma excitation to the substrate, During the gas supply process, the flow rate ratio of the impurity-containing gas and the hydrogen gas is controlled so that the partial pressure of the impurity-containing gas in the processing chamber becomes a predetermined partial pressure lower than the partial pressure at which the impurity-containing gas forms deposits containing polymers in the processing chamber.

16. A substrate method, The impurity-containing layer is conformally formed on the inner surface of the high aspect ratio structure by performing the following steps: A gas supply step of supplying an impurity-containing gas and a hydrogen gas containing impurities into a processing chamber accommodating a substrate having a high aspect ratio structure with an aspect ratio of 20 or more, a step of plasma exciting the impurity-containing gas and the hydrogen gas, and supplying active species containing the impurities generated by plasma excitation to the substrate; In the gas supply step, the flow rate ratio of the impurity-containing gas and the hydrogen gas is controlled so that the partial pressure of the impurity-containing gas in the processing chamber becomes a predetermined partial pressure lower than the partial pressure at which the impurity-containing gas forms deposits containing polymers in the processing chamber.

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