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

Abstract

The present invention relates to a substrate processing method, a substrate processing apparatus, a semiconductor device manufacturing method, and a recording medium. The present invention can make the nitrogen concentration in a film a desired concentration even at a low temperature. The substrate processing method includes: (a) a step of supplying a first gas containing a predetermined element to a substrate; (b) a step of supplying a second gas containing carbon and nitrogen to the substrate; (c) a step of supplying a gas containing nitrogen after being activated by plasma to the substrate; (d) a step of supplying a gas containing oxygen to the substrate; and (e) a step of forming a film containing at least the predetermined element, oxygen, carbon, and nitrogen on the substrate by performing the cycles of (a) to (d) for a first number of times of 2 or more or by performing the cycles of (a) to (d) sequentially for a number of times of 1 or more.

Description

Technical Field

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

[0002] Sometimes, the process involves repeatedly supplying a gas containing a predetermined element such as silicon, a gas containing carbon and nitrogen, and a gas containing oxygen to form a film containing the predetermined element, oxygen, carbon, and nitrogen on a substrate (see, for example, Patent Document 1).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2013-140944 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] However, when the film is formed at a lower temperature than previously possible, the nitrogen concentration in the film may sometimes decrease.

[0008] The purpose of this invention is to provide a technique that enables the nitrogen concentration in a membrane to reach a desired concentration even at low temperatures.

[0009] Methods for solving problems

[0010] According to one aspect of this disclosure, a technology is provided that has:

[0011] (a) A process of supplying a first gas containing a predetermined element to a substrate.

[0012] (b) The process of supplying the above-mentioned substrate with a second gas containing at least carbon and nitrogen in one molecule.

[0013] (c) A process of supplying the above-mentioned substrate with a nitrogen-containing gas that has been activated by plasma.

[0014] (d) The process of supplying oxygen-containing gas to the above-mentioned substrate.

[0015] (e) A process of forming a film containing at least predetermined elements, oxygen, carbon and nitrogen on the substrate by performing the first cycle of (a) to (d) more than twice, or by performing the cycle of (a) to (d) more than once in sequence.

[0016] Invention Effects

[0017] According to this disclosure, even at low temperatures, the nitrogen concentration in the membrane can be made to the desired concentration. Attached Figure Description

[0018] Figure 1 This is a schematic configuration example of a substrate processing apparatus according to a technical solution of the present disclosure, and the diagram shows the processing furnace part in a schematic longitudinal cross-sectional view.

[0019] Figure 2 yes Figure 1 The diagram shows a schematic cross-sectional view of the processing furnace along line AA.

[0020] Figure 3 This is a block diagram illustrating the configuration of the control unit of a substrate processing apparatus for explaining a technical solution of this disclosure.

[0021] Figure 4 middle, Figure 4 (A) is a cross-sectional view of the substrate after the first layer has been formed on the surface of the substrate. Figure 4 (B) is a cross-sectional view of the substrate after the second layer has been formed on the surface of the substrate. Figure 4 (C) is a cross-sectional view of the substrate after the third layer has been formed on the surface of the substrate. Figure 4 (D) is a cross-sectional view of the substrate after the fourth layer is formed on the surface of the substrate.

[0022] Figure 5 This is a diagram illustrating the timing of gas supply in a film-forming process according to one aspect of this disclosure.

[0023] Figure 6 This is a diagram illustrating a variation of the timing of gas supply in a film-forming process according to one aspect of this disclosure.

[0024] Figure 7 This is a diagram illustrating a variation of the timing of gas supply in a film-forming process according to one aspect of this disclosure.

[0025] Figure 8 This is a diagram illustrating a variation of the timing of gas supply in a film-forming process according to one aspect of this disclosure.

[0026] Figure 9 middle, Figure 9 (A) is a diagram showing the first layer stack of carbon nitride silicon oxide layers. Figure 9 (B) is a diagram showing the second layer stack of the carbon nitride silicon oxide layer. Figure 9 (C) is a diagram showing the third layer of the carbon nitride silicon oxide stack. Figure 9 (D) is a diagram representing the fourth layer of the carbon nitride silicon oxide stack. Figure 9 (E) is a diagram representing the fifth layer stack of carbon nitride silicon oxide layers.

[0027] Symbol Explanation

[0028] 200: Wafer (substrate), 201: Processing chamber, 202: Processing furnace, 203: Reaction tube, 121: Controller (control unit). Detailed Implementation

[0029] <One way this disclosure>

[0030] The following is mainly based on Figures 1-5 One method of this disclosure is described.

[0031] It should be noted that the accompanying drawings used in the following description are schematic, and the dimensional relationships and ratios of the elements shown in the drawings may not be consistent with reality. Furthermore, the dimensional relationships and ratios of elements may not be consistent between multiple drawings.

[0032] (1) Composition of substrate processing device

[0033] like Figure 1 As shown, the processing furnace 202 has a heater 207 that functions as a temperature regulator (heating unit). The heater 207 also functions as an activation mechanism (excitation unit) that uses heat to activate (excite) the gas.

[0034] Inside the heater 207, a reaction tube 203 is arranged concentrically with the heater 207. The reaction tube 203 is made of heat-resistant materials such as quartz (SiO2) or silicon carbide (SiC) and is formed into a cylindrical shape that is closed at the top and open at the bottom.

[0035] A sealing cap 219, serving as a furnace opening cover, is provided below the reaction tube 203 to hermetically seal the lower opening of the reaction tube 203. A sealing element (hereinafter referred to as an O-ring) 220 is disposed between the annular flange located at the lower opening end of the reaction tube 203 and the upper surface of the sealing cap 219, and the two are hermetically sealed. The processing chamber 201 is formed by at least the reaction tube 203 and the sealing cap 219. The wafer 200, which serves as a substrate, is processed within this processing chamber 201.

[0036] A wafer cassette support 218 for supporting the wafer cassette 217 is provided on the sealing cap 219.

[0037] The wafer cassette 217, which serves as a substrate support, is configured to support multiple wafers (e.g., 25 to 200 wafers) 200 arranged in a horizontal orientation and aligned with each other in a vertical direction in multiple layers.

[0038] A wafer cassette rotation mechanism 267 is provided on the side of the sealing cap 219 opposite to the processing chamber 201, which rotates the wafer cassette 217.

[0039] The sealing cap 219 is configured to move vertically by means of a wafer cassette lift 115, which is located outside the reaction tube 203 and serves as a lifting mechanism.

[0040] The above-mentioned processing furnace 202 is configured such that a wafer cassette 217, on which wafers 200 are arranged, is supported by a wafer cassette support stage 218 and inserted into a processing chamber 201.

[0041] Nozzles 410, 420, and 430 are installed in the processing chamber 201. Nozzle 410 is connected to gas supply pipe 232a, nozzle 420 is connected to gas supply pipe 232b, and nozzle 430 is connected to gas supply pipe 232c.

[0042] In gas supply pipes 232a to 232c, mass flow controllers (MFCs) 241a to 241c (flow controllers, flow control units) and valves 243a to 243c (on / off valves) are sequentially installed from the upstream side of the airflow. Gas supply pipes 232d, 232e, and 232f are connected to the downstream side of valve 243a. Gas supply pipe 232g is connected to the downstream side of valve 243b. Gas supply pipe 232h is connected to the downstream side of valve 243c. In gas supply pipes 232d to 232h, MFCs 241d to 241h and valves 243d to 243h are sequentially installed from the upstream side of the airflow.

[0043] The downstream ends of the gas supply pipes 232a to 232c are respectively connected to the ends of the nozzles 410 to 430.

[0044] The nozzle 410 is disposed in the cylindrical space between the inner wall of the reaction tube 203 and the wafer 200. Multiple gas supply holes 411 for supplying processing gas are provided on the side of the nozzle 410.

[0045] The nozzle 420 is disposed in the buffer chamber 423, which serves as a gas dispersion space (discharge chamber, discharge space).

[0046] The buffer chamber 423 is formed by the inner wall of the reaction tube 203 and the buffer chamber wall 424. A gas supply hole 425 for supplying gas is provided on the wall of the buffer chamber wall 424 adjacent to the wafer 200.

[0047] A nozzle 420 is provided along the inner wall of the reaction tube 203 from bottom to top on one end side of the buffer chamber 423. A gas supply hole 421 for supplying gas is provided on the side of the nozzle 420.

[0048] The nozzle 430 is disposed in the buffer chamber 433, which serves as a gas dispersion space (discharge chamber, discharge space).

[0049] The buffer chamber 433 is formed by the inner wall of the reaction tube 203 and the buffer chamber wall 434. A gas supply hole 435 for supplying gas is provided on the wall of the buffer chamber wall 434 adjacent to the wafer 200.

[0050] A nozzle 430 is provided along the inner wall of the reaction tube 203 from bottom to top on one end side of the buffer chamber 433. A gas supply hole 431 for supplying gas is provided on the side of the nozzle 430.

[0051] Rod-shaped electrodes 471 and 472 are disposed within the buffer chamber 423. The rod-shaped electrodes 471 and 472 are protected by electrode protection tubes 451 and 452, respectively. Rod-shaped electrode 471 is connected to a high-frequency (RF) power supply 270 via a matching adapter 271, and rod-shaped electrode 472 is connected to a ground wire 272 serving as a reference potential. As a result, plasma is generated in the plasma generation region between the rod-shaped electrodes 471 and 472. The first plasma generation structure 429 mainly consists of rod-shaped electrodes 471 and 472, electrode protection tubes 451 and 452, the buffer chamber 423, and a gas supply port 425.

[0052] Rod-shaped electrodes 481 and 482 are disposed within the buffer chamber 433. The rod-shaped electrodes 481 and 482 are protected by electrode protection tubes 461 and 462, respectively. Similar to the first plasma generating structure 429, plasma is generated in the plasma generating region between the rod-shaped electrodes 481 and 482. The second plasma generating structure 439 mainly consists of rod-shaped electrodes 481 and 482, electrode protection tubes 461 and 462, the buffer chamber 433, and a gas supply port 435.

[0053] It should be noted that the plasma generated in this manner is referred to as remote plasma. The remote plasma, generated between the electrodes, is transported to the surface of the object to be treated via gas flow and other means for plasma treatment. The active species contained in the plasma are supplied from the outer periphery of the wafer 200 towards the center of the wafer 200 through the gas supply holes 425 of the buffer chamber 423 and 435 of the buffer chamber 433.

[0054] An exhaust port 230 is provided at the lower part of the reaction tube 203. The exhaust port 230 is connected to the exhaust pipe 231.

[0055] A first gas containing a predetermined element is supplied as a processing gas into the processing chamber 201 from the gas supply pipe 232a via MFC 241a, valve 243a, and nozzle 410.

[0056] Nitrogen (N) gas is supplied as a processing gas from gas supply pipe 232b, via MFC 241b, valve 243b, and nozzle 420 into processing chamber 201.

[0057] Nitrogen (N) gas is supplied as a processing gas from gas supply pipe 232c, via MFC 241c, valve 243c, and nozzle 430 into processing chamber 201.

[0058] A second gas containing at least carbon (C) and nitrogen (N) in one molecule is supplied as a processing gas from gas supply pipe 232d, via MFC 241d, valve 243d, and nozzle 410 into processing chamber 201.

[0059] Oxygen-containing gas is supplied as a processing gas from gas supply pipe 232e, via MFC 241e, valve 243e, and nozzle 410 into processing chamber 201.

[0060] Inactive gases are supplied to the treatment chamber 201 from gas supply pipes 232f to 232h via MFCs 241f to 241h, valves 243f to 243h, gas supply pipes 232a to 232c, and nozzles 410, 420, and 430, respectively. These inactive gases function as purge gases, carrier gases, and dilution gases.

[0061] The first supply system (also known as the first gas supply system or raw material supply system) mainly consists of gas supply pipe 232a, MFC 241a, and valve 243a. The second supply system (also known as the second gas supply system) mainly consists of gas supply pipe 232d, MFC 241d, and valve 243d. The third supply system (also known as the nitrogen-containing gas supply system) mainly consists of gas supply pipe 232b, MFC 241b, valve 243b, and gas supply pipes 232c, MFC 241c, and valve 243c. The fourth supply system (also known as the oxygen-containing gas supply system or oxidizing gas supply system) mainly consists of gas supply pipe 232e, MFC 241e, and valve 243e. The inactive gas supply system mainly consists of gas supply pipes 232f-232h, MFC 241f-241h, and valves 243f-243h.

[0062] In the exhaust pipe 231, a vacuum pump 246, serving as a vacuum exhaust device, is connected via a pressure sensor 245 (which acts as a pressure detector, or pressure detection unit) and an APC (Auto Pressure Controller) valve 244 (which acts as a pressure regulator, or pressure adjustment unit). The APC valve 244 is configured to allow vacuum exhaust and vacuum exhaust to be stopped within the processing chamber 201 by opening and closing the valve while the vacuum pump 246 is operating. Furthermore, the APC valve 244 is configured to adjust the valve opening based on the pressure information detected by the pressure sensor 245 while the vacuum pump 246 is operating, thereby adjusting the pressure within the processing chamber 201.

[0063] A temperature sensor 263, which serves as a temperature detector, is installed inside the reaction tube 203. By adjusting the electrical current supplied to the heater 207 based on the temperature information detected by the temperature sensor 263, the temperature inside the processing chamber 201 can be set to the desired temperature distribution.

[0064] like Figure 3 As shown, the controller 121, serving as the control unit (control unit), is configured as a computer equipped with a CPU (Central Processing Unit) 121a, RAM (Random Access Memory) 121b, a storage device 121c, and an I / O interface 121d. The RAM 121b, storage device 121c, and I / O interface 121d are configured to exchange data with the CPU 121a via an internal bus 121e. The controller 121 is connected to an input / output device 122, such as a touch panel.

[0065] The storage device 121c is configured such as flash memory, HDD (Hard Disk Drive), SSD (Solid State Drive), etc. The storage device 121c stores, in a readable manner, a control program that controls the operation of the substrate processing apparatus, and a process recipe that describes the process, conditions, etc., of the semiconductor device manufacturing method (substrate processing method) described later. The process recipe is a combination of steps in the semiconductor device manufacturing method (substrate processing method) described later, which enables the controller 121 to execute each step to obtain a predetermined result, and functions as a program. Hereinafter, the process recipe, control program, etc., will be collectively referred to as a program. Additionally, the process recipe will be referred to simply as a process. When using the term "program" in this specification, sometimes only the process is included, sometimes only the control program is included, or sometimes both are included. RAM 121b is configured as a storage area (working area) for temporarily holding programs, data, etc., read by the CPU 121a.

[0066] I / O interface 121d is connected to the aforementioned MFC241a~241h, valves 243a~243h, pressure sensor 245, APC valve 244, vacuum pump 246, temperature sensor 263, heater 207, high-frequency power supply 270, rotating mechanism 267, wafer box lift 115, etc.

[0067] CPU 121a is configured to read and execute control programs from storage device 121c, and to read process data from storage device 121c based on input commands from input / output device 122. CPU 121a is configured to control, according to the read process data, the following actions: adjusting the flow rate of various gases by MFCs 241a-241h; opening and closing valves 243a-243h; opening and closing APC valve 244; adjusting the pressure of APC valve 244 based on pressure sensor 245; starting and stopping vacuum pump 246; adjusting the temperature of heater 207 based on temperature sensor 263; controlling the high-frequency power supplied from high-frequency power supply 270; rotating and adjusting the rotation speed of wafer cassette 217 by rotating mechanism 267; and lifting and lowering wafer cassette 217 by wafer cassette elevator 115.

[0068] The controller 121 is configured to install the aforementioned program stored in the external storage device 123 onto a computer. The external storage device 123 includes, for example, a hard disk such as an HDD, an optical disk such as a CD, an optical disk such as an MO, a USB memory, and a semiconductor memory such as an SSD. The storage device 121c and the external storage device 123 constitute a computer-readable recording medium. Hereinafter, they will also be collectively referred to as recording media. When using the term "recording medium" in this specification, sometimes only the storage device 121c is included, sometimes only the external storage device 123 is included, or sometimes both are included. Furthermore, providing the program to the computer may also be done without using the external storage device 123, but rather using communication methods such as the Internet or a dedicated line.

[0069] (2) Substrate processing process

[0070] Regarding the example of using the aforementioned substrate processing apparatus as a step in the manufacturing process of a semiconductor device to form a film containing predetermined elements, O, C, and N on a wafer 200, the main application is... Figure 5 The following description will explain the operation of each component constituting the substrate processing apparatus, which is controlled by the controller 121.

[0071] As an example of the processing flow in this method, the following example is given: by performing the non-simultaneous cycles (a) to (d) more than twice, a film containing at least the predetermined elements, O, C, and N is formed on wafer 200.

[0072] (a) The process of supplying a first gas containing a predetermined element to wafer 200.

[0073] (b) The process of supplying wafer 200 with a second gas containing at least C and N in one molecule.

[0074] (c) The process of supplying N-containing gas, which has been activated by plasma, to wafer 200.

[0075] (d) The process of supplying a gas containing O to wafer 200.

[0076] In this specification, for convenience, the processing flow of performing the above-described (a) to (d) cycles sequentially but not simultaneously a predetermined number of times is sometimes described as follows. The same expression is used in the following descriptions of other methods, variations, etc.

[0077] (First gas → Second gas → N-containing gas) * → Contains O gas) × n (n is an integer greater than or equal to 2)

[0078] Here, nitrogen-containing gas * This indicates the supply of N-containing gas after it has been activated by plasma.

[0079] In this specification, the term "wafer" sometimes refers to the wafer itself, and sometimes to a laminate of the wafer and a predetermined layer or film formed on its surface. In this specification, the term "surface of the wafer" sometimes refers to the surface of the wafer itself, and sometimes to the surface of a predetermined layer or the like formed on the wafer. In this specification, when described as "forming a predetermined layer on the wafer," it sometimes means forming the predetermined layer directly on the surface of the wafer itself, and sometimes it means forming the predetermined layer on a layer or the like formed on the wafer. The use of the term "substrate" in this specification is synonymous with the use of the term "wafer."

[0080] (Wafer loading and wafer cassette mounting)

[0081] When multiple wafers 200 are loaded (wafer loading) into the wafer cassette 217, a baffle is moved using a baffle switching mechanism, thereby opening the lower end opening of the reaction tube 203 (baffle opening). Afterwards, the wafer cassette 217, supporting multiple wafers 200, is lifted by the wafer cassette lifter 115 and moved into the processing chamber 201 (wafer cassette loading). In this state, the sealing cap 219 seals the lower end of the reaction tube 203 via the O-ring 220.

[0082] (Pressure and temperature adjustments)

[0083] Next, vacuum pump 246 is used to perform vacuum venting (pressure reduction venting) to bring the processing chamber 201, i.e., the space where the wafer 200 exists, to the desired pressure (vacuum level). At this time, the pressure inside the processing chamber 201 is measured by pressure sensor 245, and the APC valve 244 is controlled based on this measured pressure information. Additionally, heating is performed by heater 207 to bring the wafer 200 inside the processing chamber 201 to the desired processing temperature. At this time, the electrical current supplied to heater 207 is controlled based on the temperature information detected by temperature sensor 263 to achieve the desired temperature distribution inside the processing chamber 201. Furthermore, rotation of the wafer 200 is initiated using rotation mechanism 267. Venting in the processing chamber 201, heating of the wafer 200, and rotation are all performed continuously, at least until the processing of the wafer 200 is completed.

[0084] (Film forming process)

[0085] Then, proceed with steps S1 to S8 as shown below.

[0086] [First gas supply: Step S1]

[0087] Open valve 243a to allow the first gas to flow into gas supply pipe 232a. The first gas is regulated by MFC 241a, supplied into processing chamber 201 via nozzle 410, and discharged from exhaust port 230. At this time, the first gas is supplied to wafer 200. Alternatively, valves 243f to 243h can be opened to supply inactive gases into processing chamber 201 via nozzles 410 to 430, respectively.

[0088] The processing conditions for supplying the first gas in step S1 are exemplified as follows:

[0089] Processing temperature: 450~550℃

[0090] Processing pressure: 1–1200 Pa, preferably 20–200 Pa.

[0091] The first gas supply flow rate is 0.1–1.5 slm, preferably 0.1–0.5 slm.

[0092] First gas supply time: 10–60 seconds, preferably 20–40 seconds.

[0093] Inactive gas supply flow rate (per gas supply tube): 0–10 slm, preferably 3–7 slm.

[0094] It should be noted that the numerical range "1~1200Pa" in this specification means that the lower and upper limits are included within this range. Therefore, for example, "1~1200Pa" means "above 1 Pa and below 1200 Pa". The same applies to other numerical ranges. It should be noted that the processing temperature refers to the temperature of wafer 200, and the processing pressure refers to the pressure inside the processing chamber 201. It should be noted that when a supply flow rate of 0 slm is mentioned, it means that the substance is not supplied. These same points apply to the following descriptions.

[0095] As the first gas, a gas containing a predetermined element (e.g., silicon (Si), germanium (Ge), titanium (Ti), etc.) can be used. From the viewpoint of adsorption to adsorption sites (e.g., NH terminals) on the surface of wafer 200, the first gas preferably contains, for example, a halogen. The first gas preferably contains at least one of, for example, chlorine (Cl), fluorine (F), bromine (Br), and iodine (I) as a halogen, wherein, more preferably, it contains Cl.

[0096] As the first gas, a halosilane-based gas is preferred, and a chlorosilane-based gas is more preferred. Here, a halosilane refers to a silane having a halogen element as a substituent, and a chlorosilane refers to a silane having chlorine (Cl) as a substituent. Examples of halogen elements contained in the halosilane include the aforementioned halogen elements, specifically Cl, F, Br, and I. As the first gas, a halosilane containing two or more (preferably two) Si atoms per molecule is particularly preferred, and a chlorosilane containing two or more (preferably two) Si atoms per molecule is more preferred. Furthermore, as the first gas, a halosilane having an intramolecular Si-Si bond is more preferred, and a chlorosilane having an intramolecular Si-Si bond is more preferred.

[0097] For example, hexachlorosilane (Si₂Cl₆, HCDS), monochlorosilane (SiH₃Cl, MCS), dichlorosilane (SiH₂Cl₂, DCS), trichlorosilane (SiHCl₃, TCS), tetrachlorosilane (SiCl₄, STC), and octachlorotrisilane (Si₃Cl₈, OCTS) can be used as the first gas. Alternatively, fluorosilanes such as tetrafluorosilane (SiF₄) and difluorosilane (SiH₂F₂), bromosilanes such as tetrabromosilane (SiBr₄) and dibromosilane (SiH₂Br₂), and iodosilanes such as tetraiodosilane (SiI₄) and diiodosilane (SiH₂I₂) can be used as the first gas.

[0098] In addition, examples of alkyl chlorides that can be used as the first gas include dimethyldichlorosilane ((CH3)2SiCl2) gas, trimethylchlorosilane ((CH3)3SiCl) gas, 1,1,2,2-tetrachloro-1,2-dimethyldisilane ((CH3)2Si2Cl4, abbreviated as TCDMDS) gas, and 1,2-dichloro-1,1,2,2-tetramethyldisilane ((CH3)4Si2Cl2, abbreviated as DCTMDS) gas. Alkyl fluorosilane gases such as silane-based gases, dimethyl difluorosilane (CH3)2SiF2 gas, trimethyl fluorosilane ((CH3)3SiF) gas, dimethyl dibromosilane ((CH3)2SiBr2) gas, trimethyl bromidesilane ((CH3)3SiBr) gas, dimethyl diiodosilane ((CH3)2SiI2) gas, and trimethyl iodosilane ((CH3)3SiI) gas, etc.

[0099] Alternatively, as the first gas, gases containing compounds with cyclic structures composed of Si and C and halogen elements can be used, such as bis(trichlorosilyl)methane ((SiCl3)2CH2, abbreviated as BTCSM) gas, 1,2-bis(trichlorosilyl)ethane ((SiCl3)2C2H4, abbreviated as BTCSE) gas, and 1,1,3,3-tetrachloro-1,3-disilheycyclobutane (C2H4Cl4Si2, abbreviated as TCDSCB) gas.

[0100] In addition, as the first gas, for example, chlorogermanium alkane gases such as monochlorogermanium alkane (GeH3Cl), dichlorogermanium alkane (GeH2Cl2), trichlorogermanium alkane (GeHCl3), tetrachlorogermanium alkane (GeCl4), fluorogermanium alkane gases such as tetrafluorogermanium alkane (GeF4), bromogermanium alkane gases such as tetrabromogermanium alkane (GeBr4), and iodogermanium alkane gases such as tetraiodogermanium alkane (GeI4) can be used.

[0101] Alternatively, as the first gas, gases of halide metal compounds such as titanium tetrachloride (TiCl4), titanium tetrafluoride (TiF4), titanium tetrabromide (TiBr4), and titanium tetraiodide (TiI4) can be used.

[0102] One or more of the gases described above can be used as the first gas. When the first gas contains Si, it functions as a Si source; when it contains Ge, it functions as a Ge source; and when it contains Ti, it functions as a Ti source. Preferably, the first gas is at least one of a halosilane and a metal halide.

[0103] Inert gases such as nitrogen (N2), argon (Ar), helium (He), neon (Ne), and xenon (Xe) can be used as inert gases. More than one of these can be used. This also applies to the steps described later regarding the use of inert gases. Inert gases function as purge gases, carrier gases, dilution gases, etc.

[0104] Then, as Figure 4 As shown in (A), by supplying a first gas to the wafer 200 under the above-described processing conditions, a first layer 300 containing a predetermined element is formed on the surface of the wafer 200. The first layer 300 is formed by the physical or chemical adsorption of raw material molecules containing the predetermined element onto the surface of the wafer 200, the chemical adsorption of substances resulting from the partial dissociation of the raw material molecules onto the surface of the wafer 200, or the deposition of thermal decomposition products of the first gas onto the surface of the wafer 200. That is, the first layer 300 is formed by forming at least a layer containing the predetermined element (e.g., silicon (Si)) contained in the first gas that constitutes the film. Furthermore, if the first gas contains an element other than the predetermined element (e.g., a halogen), that element may also be included in the first layer 300. For example, when a chlorosilane-based gas is used as the first gas, a first layer 300 containing Si is formed as a Si-containing layer.

[0105] [Residual gas removal: Step S2]

[0106] After the first layer 300 is formed on the surface of wafer 200, valve 243a is closed to stop the supply of the first gas to the processing chamber 201. Then, vacuum exhaust is performed in the processing chamber 201 to remove the first gas remaining in the processing chamber 201, gaseous substances generated during the formation of the first layer 300, etc. At this time, valves 243f to 243h can also be opened to supply inactive gas to the processing chamber 201 through nozzles 410 to 430. The inactive gas supplied from nozzles 410 to 430 acts as a purge gas, thereby purging the processing chamber 201.

[0107] Examples of processing conditions for purging in step S2 are as follows:

[0108] Processing temperature: 450~550℃

[0109] Processing pressure: 1–500 Pa, preferably 20–100 Pa.

[0110] Inactive gas supply flow rate (per gas supply tube): 0–10 slm, preferably 1–5 slm.

[0111] Inactive gas supply time: 5 to 60 seconds, preferably 20 to 40 seconds.

[0112] [Second gas supply: Step S3]

[0113] In step S3, a second gas is supplied to wafer 200.

[0114] Specifically, valve 243d is opened, allowing the second gas to flow into gas supply pipe 232d. The flow rate of the second gas is regulated by MFC 241d, supplied into processing chamber 201 via nozzle 410, and discharged from exhaust port 230. At this time, the second gas is supplied to wafer 200. Alternatively, valves 243f to 243h can be opened to supply inactive gases into processing chamber 201 via nozzles 410 to 430, respectively.

[0115] The processing conditions for supplying the second gas in step S3 are exemplified below:

[0116] Processing temperature: 450~550℃

[0117] Processing pressure: 1–1200 Pa, preferably 600–1000 Pa.

[0118] The second gas supply flow rate is 0.1–1.5 slm, preferably 0.2–0.8 slm.

[0119] Second gas supply time: 10-120 seconds, preferably 10-60 seconds.

[0120] Other processing conditions can be the same as those in step S1.

[0121] As the second gas, a gas containing at least carbon (C) and nitrogen (N) in one molecule can be used. From the viewpoint of modification effect, the second gas preferably contains, for example, C, N, and H. That is, as the second gas, amine-based gases, organohydrazine-based gases, etc., can be used, for example.

[0122] Examples of amine gases include triethylamine ((C2H5)3N, abbreviated as TEA), monoethylamine ((C2H5)NH2, abbreviated as MEA), diethylamine ((C2H5)2NH, abbreviated as DEA), and monomethylamine ((CH3)NH2, abbreviated as MMA), dimethylamine ((CH3)2NH, abbreviated as DMA), and trimethylamine ((CH3)3N, abbreviated as TMA). It should be noted that amine gases also contain both nitrogen (N) and hydrogen (H).

[0123] As organic hydrazine gases, examples include monomethylhydrazine ((CH3)HN2H2, abbreviated as MMH), dimethylhydrazine ((CH3)2N2H2, abbreviated as DMH), and trimethylhydrazine ((CH3)2N2(CH3)H, abbreviated as TMH), etc. It should be noted that organic hydrazine gases are also gases containing both nitrogen (N) and hydrogen (H).

[0124] As the second gas, one or more of the aforementioned gases can be used. When the second gas contains both C and N, it functions not only as a source of N but also as a source of C.

[0125] By supplying a second gas to wafer 200 under the above processing conditions, such as Figure 4 As shown in (B), a second layer 400 is formed on the surface of wafer 200. The second layer 400 is formed by reacting the surface of the first layer 300 formed on the surface of wafer 200 with a second gas containing C and N in one molecule. Through this reaction, C and N contained in the second gas can be adsorbed onto the surface of the first layer 300. That is, a C and N layer is formed on the surface of the first layer 300. As a result, a second layer 400 containing predetermined elements, C and N is formed. That is, in step S3, the first layer 300 containing predetermined elements can be modified into a second layer 400 containing predetermined elements, C and N, through chemical adsorption of the second gas onto the first layer 300. Therefore, step S3 can also be referred to as a modification step using a second gas containing C and N. For example, when using a chlorosilane-based gas as the first gas and an amine-based gas as the second gas, the first layer 300, which is a Si-containing layer, is modified into a second layer 400 containing Si, C and N, i.e., a silicon carbonitride (SiCN) layer.

[0126] During the formation of the second layer 400, impurities (such as Cl) contained in the first layer 300 are removed from the first layer 300 during the modification reaction of the first layer 300 using the second gas. Thus, the second layer 400 becomes a layer with fewer impurities such as Cl compared to the first layer 300 formed in step S1. It should be noted that the impurities removed from the first layer 300 are discharged outside the processing chamber 201 by forming a gaseous substance.

[0127] [Residual gas removal: Step S4]

[0128] After the second layer 400 is formed on the surface of wafer 200, valve 243d is closed to stop the supply of the second gas into the processing chamber 201. Then, the second gas remaining in the processing chamber 201 and the gaseous substances generated during the formation of the second layer 400 are removed from the processing chamber 201 (purging) through the same processing process and conditions as the purging in step S2 above.

[0129] Here, the film-forming process of High-k film is required to be carried out at a low temperature of 450–550°C.

[0130] However, if the film-forming process is performed at a low temperature of 450–550°C, the amount (content, concentration) of nitrogen added in the second layer 400 will decrease. If the nitrogen content in the film decreases, it will also lead to a decrease (deterioration) in film quality, such as a reduction in dry etching resistance.

[0131] Therefore, in this disclosure, after step S4, the following steps S5 and S6 are performed to increase the content (concentration) of N in the membrane.

[0132] [Supplying N-containing gas activated by plasma: Step S5]

[0133] After step S4 is completed, step S5 is performed. In step S5, N-containing gas that has been activated by plasma is supplied to wafer 200.

[0134] Specifically, valves 243b and 243c are opened to allow nitrogen-containing gas to flow into gas supply pipes 232b and 232c. The flow rate of the nitrogen-containing gas is regulated by MFCs 241b and 241c and supplied to buffer chambers 423 and 433 via nozzles 420 and 430. At this time, by applying high-frequency power, the nitrogen-containing gas supplied to buffer chambers 423 and 433 is excited by plasma and, as an active species, supplied to processing chamber 201 through gas supply holes 425 and 435 and discharged from exhaust port 230. At this time, the plasma-activated nitrogen-containing gas is supplied to wafer 200. Alternatively, valve 243f can be opened to supply inactive gas to processing chamber 201 via nozzle 410.

[0135] Examples of processing conditions for supplying the plasma-activated N-containing gas in step S5 are as follows:

[0136] Processing temperature: 450~550℃

[0137] Processing pressure: 40–60 Pa

[0138] Nitrogen gas supply flow rate: 0.1–10 slm, preferably 0.5–3 slm.

[0139] The supply time of N-containing gas after plasmaification is 15–30 seconds, preferably 20 seconds.

[0140] High-frequency power: 50-400W, preferably 100-300W.

[0141] Other processing conditions can be the same as those in step S1.

[0142] As a nitrogen-containing gas, gases containing both nitrogen and hydrogen can be used. As a nitrogen-containing gas containing both nitrogen and hydrogen, hydrogen nitride-based gases can be used. Examples of hydrogen nitride-based gases include ammonia (NH3), diazepines (N2H2), hydrazine (N2H4), and N3H8.

[0143] By supplying plasma-activated nitrogen-containing gas to wafer 200 under the aforementioned processing conditions, the plasma-activated nitrogen-containing gas reacts with the second layer 400. As a result, the second layer 400 is nitrided, as... Figure 4 As shown in (C), the third layer 500 is modified to contain predetermined elements, C, and N. That is, by supplying a N-containing gas activated by plasma, the N content in the film can be increased, resulting in stronger bonding of the molecules. In other words, the third layer 500, containing predetermined elements, C, and N, is modified to have a higher N concentration than the second layer 400 and stronger bonding. For example, when using a chlorosilane-based gas as the first gas, an amine-based gas as the second gas, and a hydrogen nitride-based gas as the N-containing gas, it is modified into a silicon carbonitride (SiCN) layer.

[0144] [Residual gas removal: Step S6]

[0145] After the third layer 500 is formed on the surface of wafer 200, valves 243b and 243c are closed to stop the supply of N-containing gas to the processing chamber 201. Then, through the same processing process and conditions as the purging in step S2 above, the N-containing gas that has been activated by plasma and the gaseous substances generated during the formation of the third layer 500 that remain in the processing chamber 201 are removed from the processing chamber 201 (purging).

[0146] [O-containing gas supply: Step S7]

[0147] In step S7, an O-containing gas is supplied to the wafer 200.

[0148] Specifically, valve 243e is opened to allow O-containing gas to flow into gas supply pipe 232e. The flow rate of the O-containing gas is regulated by MFC 241e, supplied into processing chamber 201 via nozzle 410, and discharged from exhaust port 230. At this time, O-containing gas is supplied to wafer 200. Alternatively, valves 243f to 243h can be opened to supply inactive gases into processing chamber 201 via nozzles 410 to 430, respectively.

[0149] The processing conditions for supplying O-containing gas in step S7 are exemplified below:

[0150] Processing temperature: 450~550℃

[0151] Processing pressure: 1–1200 Pa, preferably 600–1000 Pa

[0152] O-containing gas supply flow rate: 0.1–10 slm, preferably 0.5–5 slm.

[0153] O-containing gas supply time: 1–30 seconds, preferably 1–15 seconds, more preferably 1–6 seconds. Other processing conditions can be the same as those in step S1.

[0154] From the viewpoint of modification effect, it is preferable, for example, to contain O, or to contain O and H, or to contain O and N, or to contain O and C. That is, as an O-containing gas, for example, an O-containing gas, an O-and H-containing gas, an O-and N-containing gas, an O-and C-containing gas, etc., can be used. It should be noted that the O-containing gas can be used not only by thermal excitation in a non-plasma atmosphere, but also by plasma excitation. That is, the O-containing gas can also be an O-containing gas excited into a plasma state.

[0155] Examples of gases containing oxygen (O) include oxygen (O2) and ozone (O3). Examples of gases containing both oxygen and hydrogen (H) include water vapor (H2O), hydrogen peroxide (H2O2), O2 + hydrogen (H2), and O3 + H2. Examples of gases containing both oxygen (O) and nitrogen (N) include nitric oxide (NO), nitrous oxide (N2O), nitrogen dioxide (NO2), O2 + NH3, and O3 + NH3. Examples of gases containing both oxygen (O) and carbon (C) include carbon dioxide (CO2) and carbon monoxide (CO).

[0156] It should be noted that in this specification, the description of "O2 gas + H2 gas" together refers to a mixture of O2 gas and H2 gas. When supplying a mixed gas, the two gases can be mixed (premixed) in the supply pipe before being supplied to the processing chamber 201, or the two gases can be supplied to the processing chamber 201 separately from different supply pipes and mixed in the processing chamber 201 (postmixed).

[0157] As an O-containing gas, one or more of the above-mentioned gases can be used. The O-containing gas functions as an O source. When the O-containing gas contains both O and N, it sometimes also functions as an N source. Additionally, when the O-containing gas contains both O and C, it sometimes also functions as a C source.

[0158] By supplying O-containing gas to wafer 200 under the above processing conditions, such as Figure 4As shown in (D), a fourth layer 600 is formed on the surface of wafer 200. Through the reaction of an O-containing gas with the third layer 500, the O contained in the O-containing gas is introduced into the third layer 500, resulting in the formation of a fourth layer 600 with introduced O. That is, in step S7, through oxidation, the third layer 500 containing predetermined elements, C, and N can be modified (oxidized) into a fourth layer 600 containing predetermined elements, C, N, and O. Therefore, step S7 can also be referred to as a modification step using an O-containing gas. Alternatively, the fourth layer 600 can also be referred to as an oxygen-containing layer or an oxide layer (modified layer). For example, if a chlorosilane-based gas is used as the first gas, an amine-based gas as the second gas, a hydrogen nitride-based gas as the N-containing gas, and an O-containing gas is used in this step, the third layer 500 containing Si, C, and N is modified into a fourth layer 600 containing Si, C, N, and O, i.e., a silicon oxycarbonate (SiOCN) layer. Thus, in this method, the N concentration in the membrane can be made high by using plasma nitriding in step S5.

[0159] [Residual gas removal: Step S8]

[0160] After the fourth layer 600 is formed on the surface of wafer 200, valve 243e is closed to stop the supply of O-containing gas to the processing chamber 201. Then, through the same processing process and conditions as the purging in step S2 above, the O-containing gas and gaseous substances generated during the formation of the fourth layer 600 that remain in the processing chamber 201 are removed from the processing chamber 201 (purging).

[0161] (Number of scheduled implementations)

[0162] By performing the cycle of steps S1 to S8 non-simultaneously (i.e., asynchronously) more than twice (the first time), or by performing the cycle of steps S1 to S8 sequentially non-simultaneously more than once (the first time), a fourth layer 600 containing at least predetermined elements, O, C, and N, is formed on the surface of the wafer 200. For example, a SiOCN film is formed as the film 600.

[0163] (Post-purging and atmospheric pressure restoration)

[0164] After a film 600 is formed on the surface of wafer 200, an inert gas is supplied as a purging gas into processing chamber 201 through nozzles 410-430, and exhaust gas is discharged from exhaust port 230. This purging process removes residual gases and reaction byproducts from processing chamber 201 (post-purging). Subsequently, the atmosphere in processing chamber 201 is replaced with an inert gas (inert gas replacement), and the pressure in processing chamber 201 is restored to atmospheric pressure (atmospheric pressure restoration).

[0165] (Wafer box unloading and wafer release)

[0166] Next, the sealing cap 219 is lowered using the wafer cassette lifter 115, opening the lower end of the reaction tube 203. Then, the processed wafer 200, supported by the wafer cassette 217, is moved from the lower end of the reaction tube 203 to the outside of the reaction tube 203 (wafer cassette unloading). After the processed wafer 200 is moved outside the reaction tube 203, it is removed from the wafer cassette 217 (wafer release).

[0167] (3) Other methods

[0168] Next, a detailed description of a variation of the film-forming process described above will be provided. In the following variations, only the differences from the above method will be described in detail.

[0169] (Variation Example 1)

[0170] In this variation, only step S3 differs from the film-forming process in the above-described method. In this variation, as... Figure 6 As shown, based on step S5, in step S3, the second gas activated by plasma is supplied to the wafer 200. Specifically, in step S3, the second gas is supplied from nozzle 420, and in step S5, nitrogen-containing gas is supplied from nozzle 430. That is, in step S3, the second gas is plasmaized using the first plasma generation structure 429, and in step S5, the nitrogen-containing gas is plasmaized using the second plasma generation structure 439. Then, after performing the above-described steps S1 and S2, step S3 is performed as shown below, and then steps S4 to S8 are performed as described above.

[0171] (First gas → Second gas * → Gas containing N * → Gas containing O) × n (n is an integer greater than or equal to 2)

[0172] Here, the second gas * This indicates the supply of a second gas that has been activated by the plasma.

[0173] [Supply the second gas activated by plasma: Step S3]

[0174] The second gas is supplied to the buffer chamber 423 via nozzle 420. At this time, by applying high-frequency electricity, the second gas supplied to the buffer chamber 423 is excited by the plasma and, as an active species, is supplied to the processing chamber 201 through the gas supply port 425 and discharged through the exhaust port 230. At this time, the plasma-activated second gas is supplied to the wafer 200. Alternatively, valves 243f and 243h can be opened to supply inactive gas to the processing chamber 201 via nozzles 410 and 430.

[0175] Examples of processing conditions for supplying the plasma-activated second gas in step S3 are as follows:

[0176] Processing temperature: 450~550℃

[0177] Processing pressure: 930 Pa

[0178] The supply flow rate of the second gas is 0.1–0.5 slm.

[0179] The supply time of the second plasma gas is 12 seconds.

[0180] High-frequency power: 50-400W, preferably 100-300W.

[0181] Other processing conditions can be the same as those in step S1.

[0182] By supplying the wafer 200 with a second gas activated by plasma under the aforementioned processing conditions, the second gas, containing C and N per molecule, is decomposed and reacts with the first layer 300 formed on the wafer 200. That is, C is introduced into the first layer 300 and it is nitrided. In other words, the first layer 300 can be modified into a second layer 400 containing predetermined elements, C and N, with C introduced and nitrided. Thus, according to this modified example, with... Figure 5 Compared to the film-forming method shown, by also activating the second gas, it is possible to achieve a higher concentration of N in the second layer 400.

[0183] (Variation Example 2)

[0184] In this modified example, steps S5 and S6 of the film-forming process described above are omitted. Furthermore, as... Figure 7 As shown, in step S3, the second gas activated by plasma is supplied to the wafer 200. Specifically, in step S3, the second gas is supplied from nozzles 420 and 430. That is, in step S3, the first plasma generating structure 429 and the second plasma generating structure 439 are used. Then, after performing the above-described steps S1 and S2, step S3 as shown below is performed, and steps S4, S7, and S8 as described above are performed.

[0185] (First gas → Second gas) * → Contains O gas) × n (n is an integer greater than or equal to 2)

[0186] [Supply the second gas activated by plasma: Step S3]

[0187] The second gas is supplied to buffer chambers 423 and 433 via nozzles 420 and 430. At this time, by applying high-frequency power, the second gas supplied to buffer chambers 423 and 433 is excited by plasma and, as an active species, is supplied to processing chamber 201 through gas supply holes 425 and 435 and discharged from exhaust port 230. At this time, the plasma-activated second gas is supplied to wafer 200. Alternatively, valve 243f can be opened to supply inactive gas to processing chamber 201 via nozzle 410.

[0188] By using this method, compared to a membrane formed by introducing the second gas without activation, or a membrane formed by introducing N without activation after introducing the second gas, the N content in the membrane can be increased. It should be noted that, compared to step S3 in Modification 1 above, the supply time of the second gas after plasma activation can also be extended. Thus, by extending the supply time of the second gas after plasma activation, the N content in the membrane can be further increased even without step S5. Furthermore, compared to the above method and Modification 1, the number of steps (working time) can be reduced, and productivity can be improved. Additionally, the other processing conditions in step S3 of this modification example can be the same as those in Modification 1 above. Among these methods, in addition to extending the supply time of the activated second gas, the RF power supplied during activation can also be increased as a way to further increase the N content in the membrane.

[0189] (Variation Example 3)

[0190] In this modified example, step S5 of the film-forming process in the above-described manner is performed simultaneously with step S3. That is, as follows: Figure 8 As shown, in step S3, while supplying the second gas to the wafer 200, N-containing gas activated by plasma is also supplied. That is, after performing the above-described steps S1 and S2, step S5 is performed simultaneously with step S3, and after removing the residual gas, the above-described steps S7 and S8 are performed.

[0191] (First gas → Second gas + N-containing gas) * → Contains O gas) × n (n is an integer greater than or equal to 2)

[0192] According to this modified example, compared with the above-described method and Modification 1, by simultaneously supplying the second gas and the N-containing gas, the purging process can be eliminated, the processing time can be shortened, and the productivity can be improved. Furthermore, since the plasma-activated N-containing gas is supplied simultaneously with the second gas into the processing chamber 201, the second gas is also indirectly excited by the plasma. Therefore, compared with the case where the film is formed without using plasma, the N concentration in the film can be increased.

[0193] According to this disclosure, even with low-temperature processes, by utilizing plasma-enhanced nitriding, it is possible to obtain SiOCN films with the same (equivalent) low dielectric constant and wet etching rate as SiOCN films formed at high temperatures, and with good dry etching resistance.

[0194] (4) Stacked Example

[0195] Figure 9 (A) Figure 9 (E) indicates a stacked example using a film formed through the above film-forming process.

[0196] Here, since the membrane 600 formed by the above method and various modifications is formed by supplying N-containing gas activated by plasma, it is believed that C in the membrane may be removed due to plasma excitation, and the C concentration in the membrane may decrease.

[0197] Therefore, in this disclosure, the following film stacks (laminations) are employed: a film containing predetermined elements, C, O, and N, formed by supplying a plasma-activated N-containing gas to a wafer 200; and a film containing at least predetermined elements, C, and N, formed without supplying a plasma-activated N-containing gas to the wafer 200. This allows for the maintenance of both the C and N concentrations in the film. In other words, by employing a stacked structure of a film formed using plasma and a film formed without plasma, a SiOCN film with desired C and N concentrations in the stacked film can be obtained.

[0198] Specifically, for example, the following films are stacked: a SiO(C)N film formed by supplying a plasma-activated N-containing gas to a wafer 200, and a Si(O)CN film formed without supplying a plasma-activated N-containing gas. By employing this stacking process, both the appropriate desired C and N concentrations in the films can be maintained. For example, the SiO(C)N film formed by supplying a plasma-activated N-containing gas increases the N concentration, thus achieving the desired N concentration. On the other hand, in the Si(O)CN film formed without supplying a plasma-activated N-containing gas, the N concentration does not increase, but no C loss occurs, thus achieving the desired C concentration. Furthermore, the balance of C and N concentrations in the stacked film is adjusted by adjusting the ratio of the number of execution cycles of each process in the stacked film (also called a laminated film). Here, SiO(C)N film refers to SiOCN film or SiON film, and Si(O)CN film refers to SiOCN film or SiCN film.

[0199] Film 600 is a film containing predetermined elements, C, O and N, formed by performing steps S1 to S8 of the film formation process in the above-described manner using the above-described substrate processing apparatus.

[0200] Film 700 is a film containing predetermined elements, C and N, formed by performing steps S1 to S4 of the film formation process in the above-described manner using the substrate processing apparatus, without supplying the plasma-activated N-containing gas to the wafer 200. That is, film 700 is a substantially oxygen-free film.

[0201] Film 800 is a film containing predetermined elements, C, O and N, formed by performing steps S1 to S4, S7 and S8 of the film formation process in the above manner using the above-described substrate processing apparatus without supplying N-containing gas activated by plasma.

[0202] It should be noted that the processing temperature for forming membranes 700 and 800 is the same as that for forming membrane 600, which is 450–550°C.

[0203] Figure 9 (A) is a diagram representing the first layer of stacking. In Figure 9 In (A), when steps S1 to S8 of the film-forming process described above are performed more than twice, the cycles are repeated such that the C concentration and N concentration of the film 600 formed in each cycle are different. That is, multiple films 600 formed under different processing conditions are stacked to form a laminated film. For example, by increasing the N concentration of the film 600 on the outermost surface (top layer) of the wafer 200, the etch resistance to dry etching is improved, for example. Furthermore, by setting the C concentration of the film 600 on the bottom layer of the wafer 200 to approximately 10%, leakage current is reduced. In other words, the C concentration and N concentration of each film 600 are adjusted to form a laminated film. That is, depending on the application, each film 600 is formed with different C and N concentrations.

[0204] Here, the C concentration of each membrane 600 can be changed by the following methods. For example, to reduce the C concentration, it can be done by decreasing the partial pressure of the second gas containing C, increasing the supply of N gas, increasing the plasma nitriding time (supplying N gas activated by plasma), increasing the oxidation time (supplying O gas), etc. Conversely, to increase the C concentration, it can be done by increasing the partial pressure of the second gas containing C, decreasing the supply of N gas, decreasing the plasma nitriding time (supplying N gas activated by plasma), decreasing the oxidation time (supplying O gas), etc.

[0205] Figure 9 (B) is a diagram representing the second layer of stacking. In Figure 9In (B), steps S1 to S4, S7, and S8 of the film formation process described above are performed to form film 800. Then, steps S1 to S4 are performed to form film 700. Finally, the cycle of performing steps S1 to S8 non-simultaneously is repeated at least twice to form film 600, thereby forming a stacked film. That is, the process of forming film 800 containing predetermined elements, C, O, and N without plasma treatment suitable for film 600, and forming film 700 containing C and N but substantially free of O without plasma treatment suitable for film 600, are performed non-simultaneously once (second time). Then, the process of forming film 600 is performed at least twice (first time), thereby forming a film containing at least predetermined elements, O, C, and N on wafer 200. In other words, only film 600 on the outermost surface of wafer 200 is formed multiple times. As the bottom layer of wafer 200, i.e. the substrate, a film 800 with a high C concentration is formed, and a film 600 with a high N concentration is formed on the outermost surface.

[0206] Membrane 700 is formed, for example, by the following process.

[0207] (First gas → Second gas) × n (n is an integer greater than or equal to 1)

[0208] Membrane 800 is formed, for example, by the following process.

[0209] (First gas → Second gas → O-containing gas) × n (n is an integer greater than or equal to 1)

[0210] The first and second times mentioned above can be different. Moreover, by adjusting the first and second times, the ratio of C to N in the film formed on wafer 200 containing at least predetermined elements, O, C, and N can be changed. That is, the concentration balance of C and N in the film can be adjusted.

[0211] Here, when using SiOCN films as sidewall spacers for transistor gates, and when using them as multilayer films, for example, each film has a thickness of several... The thickness of the laminated membrane is Furthermore, the thickness of the SiOCN film used for embedding in trenches, etc., is, for example, [missing information]. Thus, the necessary thickness of the SiOCN film varies depending on the application. If the film 700 between film 800 and film 600 is made too thick, there is a possibility of increased leakage current. Furthermore, if film 700 is made too thin, C may sometimes be released during plasma nitriding. Therefore, the thickness of film 700 is adjusted so that approximately 10% of C remains.

[0212] It should be noted that the following processes can also be repeated a predetermined number of times to form a laminated film: the process of forming film 800 by performing steps S1 to S4, S7 and S8 of the film formation process described above; the process of forming film 700 by performing steps S1 to S4; and the process of forming film 600 by performing steps S1 to S8. That is, a film containing at least predetermined elements, O, C and N can be formed on wafer 200 by repeating the process of forming film 800, forming film 700 and forming film 600 not simultaneously once or more (the third time).

[0213] Here, the third number is different from the first number mentioned above. Moreover, by adjusting the first and third numbers, the ratio of C and N contained in the film formed on wafer 200 containing at least predetermined elements, O, C, and N can be changed, and the concentration balance of C and N in the film can be adjusted.

[0214] Figure 9 (C) is a diagram representing the third layer of stacking. In Figure 9 In step (C), film 700 is formed by performing steps S1 to S4 of the film formation process described above. Then, steps S1 to S4, S7, and S8 are performed to form film 800. Finally, the cycle of performing steps S1 to S8 non-simultaneously is repeated at least twice to form film 600, thereby forming a laminated film. That is, after performing the steps of forming film 700 containing C and N but substantially free of O without plasma treatment suitable for film 600 and forming film 800 containing predetermined elements, C, O, and N without plasma treatment suitable for film 600, non-simultaneously, the cycle of forming film 600 is repeated at least twice (the first time), thereby forming a film containing at least the elements O, C, and N on wafer 200. In other words, only film 600 on the outermost surface of wafer 200 is formed multiple times. In this way, by forming an O-free film 700 as the substrate of the bottom layer of the wafer 200, for example, when gate metal is present under the film 700, oxidation of the gate metal can be suppressed.

[0215] Furthermore, by adjusting the first and second times, the ratio of C and N contained in the film formed on the wafer 200 containing at least predetermined elements, O, C, and N can be changed, and the concentration balance of C and N in the film can be adjusted.

[0216] It should be noted that the following processes can also be repeated a predetermined number of times to form a laminated film: the process of forming film 700 by performing steps S1 to S4 of the film formation process described above, the process of forming film 800 by performing steps S1 to S4, S7, and S8, and the process of forming film 600 by performing steps S1 to S8. That is, a film containing at least predetermined elements, O, C, and N can be formed on wafer 200 by performing the processes of forming film 700, forming film 800, and forming film 600 sequentially but not simultaneously once or more (the third time). Figure 9 (B) and Figure 9 In (C), a structure is shown with membranes 600, 700, and 800 stacked, but it could also be a structure with either membrane 700 or 800 without plasma treatment and membrane 600 with plasma treatment. By stacking these two types of membranes, the concentration balance of C and N in the membrane can be adjusted. For example, it is desirable to form the membrane such that the SiOCN membrane as a laminate has a first N concentration and a first C concentration. In this case, the nitrogen concentration of the membrane formed by plasma treatment can be set to a second N concentration that is higher than the first N concentration. In this case, the C concentration of the membrane may be lower than the first C concentration. On the other hand, the carbon concentration of the membrane formed without plasma treatment can be set to a second C concentration that is higher than the first C concentration. In this case, the N concentration of the membrane may be lower than the first N concentration. By appropriately combining these membranes, as a laminated membrane as a whole, a membrane with the desired concentrations can be obtained. Using such methods, it is possible to fabricate SiOCN films with equivalent properties in terms of dielectric constant, wet etching rate, and dry etching resistance, even at low temperatures, compared to SiOCN films formed at high temperatures.

[0217] Here, the third number can also be different from the first number mentioned above. Moreover, by adjusting the first and third numbers, the ratio of C and N contained in the film formed on wafer 200 containing at least predetermined elements, O, C, and N can be changed, and the concentration balance of C and N in the film can be adjusted.

[0218] Figure 9 (D) is a diagram representing the fourth layer of stacking. In Figure 9In step (D), film 600 is formed by performing steps S1 to S8 of the film formation process described above, followed by steps S1 to S4 to form film 700. Then, steps S1 to S8 are repeated a predetermined number of times to form film 600, thereby forming a laminated film. That is, the process of forming film 600 and film 700, which are not performed simultaneously, is repeated once (second time), and then the process of forming film 600 is repeated more than twice (first time), thereby forming a film containing at least predetermined elements, O, C, and N, on wafer 200. That is, only film 600 on the outermost surface of wafer 200 is formed multiple times, and film 700 is formed between films 600. That is, a film 700 with a high C concentration that is substantially free of O is formed between films 600. That is, a laminated film can be formed with different C and N concentrations in the film 600 on the outermost surface and the film 600 on the bottom of wafer 200. Furthermore, by forming a membrane 700 between membranes 600, the reduction of C caused by plasma can be suppressed, and the decrease in C concentration of the stacked membrane can be suppressed. Additionally, membrane 700 serves as a... It can remain unaffected by the value of k, which is the relative permittivity.

[0219] Furthermore, depending on the application, the C and N concentrations in the bottommost film 600 of wafer 200 are different from those in the outermost film 600. By adjusting the first and second iterations, the ratio of C to N in the film containing predetermined elements, O, C, and N formed on wafer 200 can be changed, thereby adjusting the concentration balance of C and N in the film.

[0220] It should be noted that the following processes can also be repeated sequentially a predetermined number of times to form a laminated film: the process of forming film 600 by performing steps S1 to S8 of the film formation process described above, the process of forming film 700 by performing steps S1 to S4, and the process of forming film 600 by performing steps S1 to S8. That is, by sequentially performing the process of forming film 600, forming film 700 containing C and N but substantially free of O without using plasma treatment suitable for film 600, and the process of forming film 600 once or more (the third time), a film containing at least predetermined elements, O, C, and N can be formed on wafer 200. In addition, depending on the application, the C and N concentrations in the bottommost film 600 of wafer 200 can be different from the C and N concentrations in the outermost film 600.

[0221] Figure 9 (E) is a diagram representing the fifth layer of stacking. In Figure 9In step (E), film 600 is formed by performing steps S1 to S8 of the film formation process described above. Then, steps S1 to S4, S7, and S8 are performed to form film 800. Steps S1 to S8 are then repeated a predetermined number of times to form film 600, thereby forming a stacked film. That is, after performing the process of forming film 600 separately and the process of forming film 800 containing predetermined elements, C, O, and N without using plasma treatment suitable for film 600, the process of forming film 600 is performed once (second number), and then the process of forming film 600 is performed more than twice (first number). Thus, a film containing at least predetermined elements, O, C, and N is formed on wafer 200. In other words, only film 600 on the outermost surface of wafer 200 is formed multiple times, and film 800 is formed between films 600. That is, a multilayer film can be formed with different C and N concentrations in the outermost film 600 and the bottommost film 600 of the wafer 200. Furthermore, by forming a film 800 between the films 600, C can be replenished, and the decrease in C concentration in the multilayer film caused by plasma processing can be suppressed. It should be noted that the above method describes an example where the steps are not performed simultaneously, but simultaneous performance of the steps is also possible as long as it does not affect the film properties.

[0222] Furthermore, by adjusting the first and second times, the ratio of C and N contained in the film formed on the wafer 200 containing at least predetermined elements, O, C, and N can be changed, and the concentration balance of C and N in the film can be adjusted.

[0223] It should be noted that the following processes can also be repeated sequentially a predetermined number of times to form a laminated film: the process of forming film 600 by performing steps S1 to S8 of the film formation process described above, the process of forming film 800 by performing steps S1 to S4, S7 and S8, and the process of forming film 600 by performing steps S1 to S8. That is, by performing the process of forming film 600, forming film 800 and forming film 600 non-simultaneously once or more (the third time), a film containing at least predetermined elements, O, C and N can be formed on wafer 200.

[0224] As described above, according to this disclosure, the formation order, thickness, and combination of the layers in a laminated film can be changed according to the intended use.

[0225] Furthermore, the film formed by the above method and its variations can be used for embedding in sidewall spacers, trenches, slots, and other recesses of MOS transistors.

[0226] The above provides a detailed description of the methods, variations, and stacking examples of this disclosure. However, this disclosure is not limited to the methods, variations, and stacking examples described above, and various changes can be made without departing from its main idea.

Claims

1. A substrate processing method, comprising: (a) A process of supplying a first gas containing a predetermined element to a substrate, (b) The step of supplying the substrate with a second gas that does not contain the predetermined element, and at least one of an amine gas and an organic hydrazine gas. (c) The process of supplying the substrate with plasma-activated hydrogen nitride gas, (d) The process of supplying oxygen-containing gas to the substrate, and (e) A process of forming a film containing at least the predetermined elements, oxygen, carbon, and nitrogen on the substrate by performing the first cycle of (a) to (d) more than twice, or by performing the cycles of (a) to (d) more than once in sequence. The second gas is at least one of triethylamine gas, monoethylamine gas, diethylamine gas, monomethylamine gas, dimethylamine gas, trimethylamine gas, monomethylhydrazine gas, dimethylhydrazine gas, and trimethylhydrazine gas.

2. The substrate processing method according to claim 1, wherein, It also includes: (f) a process of forming a film containing at least the predetermined elements, carbon, and nitrogen on the substrate without supplying the nitrogen-containing gas activated by plasma. By performing the cycles of (e) and (f) more than once, a film containing at least the predetermined elements, oxygen, carbon, and nitrogen is formed on the substrate.

3. The substrate processing method according to claim 2, wherein, The first number of times is different from the second number of times.

4. The substrate processing method according to claim 2, wherein, By adjusting the first and second number of times, the carbon to nitrogen ratio in the membrane containing at least the predetermined elements, oxygen, carbon, and nitrogen is changed.

5. The substrate processing method according to claim 2, wherein, It also includes: (g) a process of forming a film containing at least the predetermined elements, carbon, oxygen, and nitrogen on the substrate without supplying the nitrogen-containing gas activated by plasma. By performing the non-simultaneous cycles (e), (f), and (g) more than once for a third time, a film containing at least the predetermined elements, oxygen, carbon, and nitrogen is formed on the substrate.

6. The substrate processing method according to claim 5, wherein, The first number is different from the third number.

7. The substrate processing method according to claim 5, wherein, By adjusting the first number and the third number, the carbon to nitrogen ratio in the membrane containing at least predetermined elements, oxygen, carbon and nitrogen is changed.

8. The substrate processing method according to claim 1, wherein, In (e), when performing the cycles from (a) to (d) at least twice, the cycles are performed in such a way that the carbon concentration in the membranes containing the predetermined elements, oxygen, carbon, and nitrogen formed in each cycle is different.

9. The substrate processing method according to claim 1, wherein, In (e), when performing the cycles from (a) to (d) at least twice, the cycles are performed in such a way that the nitrogen concentration in the membranes containing the predetermined elements, oxygen, carbon and nitrogen formed in each cycle is different.

10. The substrate processing method according to claim 2, wherein, (e) follows (f).

11. The substrate processing method according to claim 10, wherein, In (e), (a) through (d) are performed at least twice.

12. The substrate processing method according to claim 5, wherein, (g) follows (f).

13. The substrate processing method according to claim 12, wherein, (f) follows (g).

14. The substrate processing method according to claim 2, wherein, In (e), (a) to (d) are performed multiple times, and (f) is performed between multiple (a) to (d).

15. The substrate processing method according to claim 1, wherein, The second gas also contains hydrogen.

16. A method for manufacturing a semiconductor device, comprising: (a) A process of supplying a first gas containing a predetermined element to a substrate, (b) The step of supplying the substrate with a second gas that does not contain the predetermined element, and at least one of an amine gas and an organic hydrazine gas. (c) The process of supplying the substrate with plasma-activated hydrogen nitride gas. (d) The process of supplying oxygen-containing gas to the substrate, and (e) A process of forming a film containing at least the predetermined elements, oxygen, carbon, and nitrogen on the substrate by performing the first cycle of (a) to (d) more than twice, or by performing the cycle of (a) to (d) more than once in sequence. The second gas is at least one of triethylamine gas, monoethylamine gas, diethylamine gas, monomethylamine gas, dimethylamine gas, trimethylamine gas, monomethylhydrazine gas, dimethylhydrazine gas, and trimethylhydrazine gas.

17. A computer-readable recording medium having a program recorded thereon that causes a substrate processing apparatus to perform the following processes via a computer: Inside the processing chamber of the substrate processing apparatus, (a) The process of supplying a first gas containing a predetermined element to a substrate. (b) A process of supplying the substrate with a second gas that does not contain the predetermined element, and at least one of an amine gas and an organic hydrazine gas. (c) The process of supplying the substrate with plasma-activated hydrogen nitride gas. (d) The process of supplying oxygen-containing gas to the substrate. (e) A process of forming a film containing at least the predetermined elements, oxygen, carbon, and nitrogen on the substrate by performing the first cycle of (a) to (d) more than twice, or by performing the cycle of (a) to (d) more than once in sequence. The second gas is at least one of triethylamine gas, monoethylamine gas, diethylamine gas, monomethylamine gas, dimethylamine gas, trimethylamine gas, monomethylhydrazine gas, dimethylhydrazine gas, and trimethylhydrazine gas.

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