Substrate processing methods, semiconductor device manufacturing methods, processes, and substrate processing apparatus

Abstract

The process includes: (a-1) supplying a first raw material gas containing a first element to the substrate; (a-2) supplying a first reaction gas to the substrate; repeating this process a first time to form a first layer containing the first element; and (b-1) supplying a second raw material gas containing the first element and a first halogen element to the substrate; (b-2) after the first period of supplying the second raw material gas in (b-1) has been completed, supplying a third raw material gas containing a second halogen element and a second element not present in the first layer to the substrate; and (b-3) after the second period of supplying the third raw material gas in (b-2) has been completed, supplying a second reaction gas to the substrate; repeating this process a second time to form a second layer containing the first element and the second element; thereby forming a film containing the first element and the second element on the substrate.

Description

Technical Field

[0001] This disclosure relates to substrate processing methods, semiconductor device manufacturing methods, programs, and substrate processing apparatus. Prior Technology

[0002] As a step in the manufacturing process of a semiconductor device, there is a process in which a specified gas is supplied to a substrate to form a film on the substrate (see, for example, Patent Document 1). [Previous Technical Documents] [] [Patent Literature] [] []

[0003] Patent Document 1: Japanese Patent Application Publication No. 2016-18907 Summary of the Invention

[0004] [The problem the invention aims to solve] This disclosure provides a technique that enables controlled improvement in the composition ratio of specified elements added to a membrane. [Technical means to solve the problem] [] []

[0005] According to one aspect of this disclosure, a technique is provided for: The process will include: (a-1) supplying a first raw material gas containing a first element to the substrate; (a-2) The process of supplying the first reaction gas to the aforementioned substrate; The cycle is repeated for the first time, thereby forming the first process of the first layer containing the aforementioned first element; The process will include: (b-1) supplying the aforementioned substrate with a second raw material gas containing the aforementioned first element and the first halogen element; (b-2) After the first period of supplying the second raw material gas mentioned in (b-1) has been carried out, a process of supplying the substrate with a third raw material gas containing a second halogen element and a second element not present in the first layer; (b-3) The process of supplying the second reaction gas to the substrate after the second period of supplying the third raw material gas mentioned in (b-2); The cycle is repeated a second time, thereby forming a second process of a second layer containing the aforementioned first element and the aforementioned second element; In this way, a film containing the aforementioned first element and the aforementioned second element is formed on the aforementioned substrate. [Effects of the Invention] [] []

[0006] According to this disclosure, the controllability of the composition ratio of specified elements added to the membrane can be improved. Simple Explanation of the Diagram

[0007] [Figure 1] Figure 1 is a schematic diagram of the longitudinal processing furnace of a substrate processing apparatus preferably used in one embodiment of the present disclosure. It is a diagram showing the processing furnace 202 in a longitudinal cross-sectional view. [Figure 2] Figure 2 is a schematic diagram of the longitudinal processing furnace of a substrate processing apparatus preferably used in one of the present invention. It is a schematic diagram of the processing furnace 202 section with the AA line in Figure 1. [Figure 3] Figure 3 is a schematic diagram of the controller 121 of a substrate processing apparatus preferably used in one embodiment of the present disclosure. It is a block diagram illustrating the control system of the controller 121. [Figure 4] Figure 4 is a diagram illustrating the processing sequence in one of the states disclosed herein. [Figure 5] Figure 5 is an example of the cross-sectional structure of a NAND memory cell. [Figure 6] Figure 6(a) is a diagram illustrating the processing sequence in Modification 1 of this disclosure. Figure 6(b) is a diagram illustrating the processing sequence in Modification 2 of this disclosure. [Figure 7] Figure 7(a) is a diagram illustrating one example of the processing sequence in Modified Example 3 of this disclosure. Figure 7(b) is a diagram illustrating another example of the processing sequence in Modified Example 3 of this disclosure. [Figure 8] Figure 8(a) is a diagram illustrating the processing sequence in Modification 4 of this disclosure. Figure 8(b) is a diagram illustrating the processing sequence in Modification 5 of this disclosure. Figure 8(c) is a diagram illustrating the processing sequence in Modification 6 of this disclosure. [Figure 9] Figure 9 is a diagram illustrating the charge trapping film formed by the processing sequence in Modified Example 1 disclosed herein. Implementation

[0008] <This reveals a pattern> The following description mainly refers to Figures 1 to 5 to illustrate one aspect of this disclosure. Furthermore, the figures used in the following description are all modeled objects, and the dimensional relationships and ratios of the elements shown in the figures may not be consistent with the actual objects. Moreover, the dimensional relationships and ratios of the elements may not be consistent between multiple figures.

[0009] (1) Composition of substrate processing device As shown in Figure 1, the processing furnace 202 has a heater 207 that functions as a temperature regulator (heating unit). The heater 207 is cylindrical and is vertically mounted by means of a retaining plate. The heater 207 also functions as an activation mechanism (activation unit) that activates (excites) the gas by heat.

[0010] Inside the heater 207, a reaction tube 203 is arranged concentrically with the heater 207. Below the reaction tube 203, a manifold 209 is arranged concentrically with the reaction tube 203. The upper end of the manifold 209 engages with the lower end of the reaction tube 203, thus supporting the reaction tube 203. An O-ring 220a, serving as a sealing member, is provided between the manifold 209 and the reaction tube 203. The processing container (reaction container) is mainly constructed by the reaction tube 203 and the manifold 209. A processing chamber 201 is formed in the hollow portion of the processing container. The processing chamber 201 is configured to accommodate a wafer 200, which serves as a substrate. The wafer 200 is processed within this processing chamber 201.

[0011] Inside the processing chamber 201, nozzles 249a and 249b, serving as the first and second supply units, are each installed through the side wall of the manifold 209. Nozzles 249a and 249b are also referred to as the first nozzle and the second nozzle, respectively. Gas supply pipes 232a and 232b are connected to each of the nozzles 249a and 249b. Nozzles 249a and 249b are distinct nozzles, and are arranged adjacent to each other.

[0012] In gas supply pipes 232a and 232b, flow controllers (flow control units), namely mass flow controllers (MFCs) 241a and 241b, and on / off valves, namely valves 243a and 243b, are sequentially provided from the upstream side of the gas flow. Downstream of valve 243a in gas supply pipe 232a, gas supply pipes 232c-232e and 232g are connected. Downstream of valve 243b in gas supply pipe 232b, gas supply pipes 232f and 232h are connected. In gas supply pipes 232c-232h, MFCs 241c-241h and valves 243c-243h are sequentially provided from the upstream side of the gas flow.

[0013] As shown in Figure 2, nozzles 249a and 249b, in the annular space between the inner wall of the reaction tube 203 and the wafer 200 (viewed from above), are vertically arranged from the lower part to the upper part of the inner wall of the reaction tube 203, each facing upwards towards the arrangement direction of the wafer 200. That is, nozzles 249a and 249b are horizontally arranged around the wafer arrangement area to the side of the wafer arrangement area for arranging the wafer 200, each arranged along the wafer arrangement area. On the side of nozzles 249a and 249b, gas supply holes 250a and 250b are provided for supplying gas. Gas supply holes 250a and 250b each open towards the center of the reaction tube 200 (viewed from above), allowing gas to be supplied towards the wafer 200. Multiple gas supply holes 250a and 250b are arranged from the lower part to the upper part of the reaction tube 203.

[0014] The first raw material gas containing the first element is supplied from the gas supply pipe 232a through MFC 241a, valve 243a, and nozzle 249a into the processing chamber 201.

[0015] The first reaction gas is supplied from the gas supply pipe 232b through MFC 241b, valve 243b, and nozzle 249b into the processing chamber 201.

[0016] The second raw material gas containing the first element and the first halogen element is supplied from the gas supply pipe 232c through MFC241c, valve 243c, gas supply pipe 232a, and nozzle 249a into the processing chamber 201.

[0017] The third raw material gas containing the second halogen element and the specified second element is supplied from the gas supply pipe 232d through MFC 241d, valve 243d, gas supply pipe 232a, and nozzle 249a into the processing chamber 201.

[0018] A fourth raw material gas containing a first element, a third halogen element, and hydrogen (H) is supplied from the gas supply pipe 232e through MFC 241e, valve 243e, gas supply pipe 232a, and nozzle 249a into the processing chamber 201.

[0019] The second reaction gas is supplied from the gas supply pipe 232f through MFC 241f, valve 243f, gas supply pipe 232b, and nozzle 249b into the processing chamber 201.

[0020] Inactive gases are supplied to the treatment chamber 201 from gas supply pipes 232g and 232h via MFCs 241g and 241h, valves 243g and 243h, gas supply pipes 232a and 232b, and nozzles 249a and 249b, respectively. These inactive gases serve as purge gases, carrier gases, and dilution gases.

[0021] The first raw material gas supply system is mainly composed of gas supply pipe 232a, MFC 241a, and valve 243a. The first reactive gas supply system is mainly composed of gas supply pipe 232b, MFC 241b, and valve 243b. The second raw material gas supply system is mainly composed of gas supply pipe 232c, MFC 241c, and valve 243c. The third raw material gas supply system is mainly composed of gas supply pipe 232d, MFC 241d, and valve 243d. The fourth raw material gas supply system is mainly composed of gas supply pipe 232e, MFC 241e, and valve 243e. The second reactive gas supply system is mainly composed of gas supply pipe 232f, MFC 241f, and valve 243f. The inactive gas supply system is mainly composed of gas supply pipes 232g and 232h, MFC 241g and 241h, and valves 243g and 243h. A gas supply system may be constituted by all or at least one of the aforementioned supply systems. Alternatively, nozzles connected to the gas supply pipes constituting the aforementioned supply systems may each be included within that supply system.

[0022] Among the various supply systems mentioned above, any one or all of the supply systems can also constitute an integrated supply system 248 formed by integrating valves 243a~243h or MFC241a~241h, etc.

[0023] Below the side wall of the reaction tube 203, there is an exhaust port 231a for venting the environment inside the processing chamber 201. An exhaust pipe 231 is connected to the exhaust port 231a. A vacuum pump 246, serving as a vacuum venting device, is connected to the exhaust pipe 231 via a pressure sensor 245 (a pressure detector, or pressure detection unit) and an APC (Auto Pressure Controller) valve 244 (a pressure regulator, or pressure adjustment unit). The APC valve 244 is configured to allow for vacuum venting and stopping of vacuum venting within the processing chamber 201 by opening and closing the valve while the vacuum pump 246 is operating. Furthermore, while the vacuum pump 246 is operating, the pressure inside the processing chamber 201 can be adjusted by regulating the valve opening based on pressure information detected by the pressure sensor 245. The exhaust system is mainly composed of the exhaust pipe 231, the APC valve 244, and the pressure sensor 245. The vacuum pump 246 can also be thought of as being included in the exhaust system.

[0024] Below the manifold 209, a cap 219, serving as a furnace opening cover, is provided to hermetically seal the lower opening of the manifold 209 through an O-ring 220b. Below the cap 219, a rotation mechanism 267 is provided to rotate the crystal boat 217 (described later). The rotation shaft 255 of the rotation mechanism 267 passes through the cap 219 and is connected to the crystal boat 217. The rotation mechanism 267 is configured to rotate the wafer 200 by rotating the crystal boat 217. The cap 219 is configured to be raised and lowered vertically by a crystal boat elevator 115, which is located outside the reaction tube 203 and serves as a lifting mechanism. The crystal boat elevator 115, by raising and lowering the cap 219, is configured as a conveying device (conveyor) for moving the wafer 200 in and out of the processing chamber 201.

[0025] Below the manifold 209, there is a gate 219s, which serves as a furnace opening cover, allowing the lower opening of the manifold 209 to be airtightly sealed through an O-ring 220c when the cap 219 is lowered and the crystal boat 217 is removed from the processing chamber 201. The opening and closing action (lifting or rotating action, etc.) of the gate 219s is controlled by the gate opening and closing mechanism 115s.

[0026] The crystal boat 217, which serves as a support, is configured to support multiple wafers 200, for example 25 to 200, in a horizontal position and with their centers aligned in the vertical direction, in a multi-segment arrangement, or to support them at intervals. At the lower part of the crystal boat 217, heat insulation plates 218 are supported in multiple segments.

[0027] A temperature sensor 263, serving as a temperature detector, is installed inside the reaction tube 203. The power supply to the heater 207 is adjusted based on the temperature information detected by the temperature sensor 263, thereby achieving the desired temperature distribution within the processing chamber 201. The temperature sensor 263 is installed along the inner wall of the reaction tube 203.

[0028] As shown in Figure 3, the control unit (control means), also known as the controller 121, is configured as a computer equipped with a CPU (Central Processing Unit) 121a, RAM (Random Access Memory) 121b, a memory device 121c, and I / O ports 121d. The RAM 121b, memory device 121c, and I / O ports 121d are configured to exchange data with the CPU 121a via an internal bus 121e. An input / output device 122, configured as a touch panel, is connected to the controller 121. Furthermore, an external memory device 123 can be connected to the controller 121. The board processing apparatus can be configured to have one control unit or multiple control units. That is, it can be designed to use one control unit to control the processing sequence described later, or it can be designed to use multiple control units. Furthermore, multiple control units can also be configured into a control system interconnected by wired or wireless communication networks, or designed to control the processing sequence described later by the entire control system. In this specification, the term "control unit" refers not only to a single control unit, but also to a combination of multiple control units, or a control system comprised of multiple control units.

[0029] The memory device 121c is constructed, for example, by flash memory, HDD (Hard Disk Drive), SSD (Solid State Drive), etc. Within the memory device 121c, a control program that controls the operation of the board processing device, or a process recipe that describes the procedures or conditions of the board processing described later, can be readablely recorded and stored. The process recipe, which is used to enable the board processing device to execute the various procedures in the board processing described later by the controller 121 to obtain a specified result, is called a program. Hereinafter, the process recipe or control program will be collectively referred to as a program. Furthermore, the process recipe will also be simply referred to as a recipe. In this specification, when the term "program" is used, there may be a case where only a recipe is included, a case where only a control program is included, or a case where both are included. RAM 121b constitutes a memory area (working area) for temporarily storing programs or data read by the CPU 121a.

[0030] I / O port 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, rotating mechanism 267, crystal boat elevator 115, gate opening and closing mechanism 115s, etc.

[0031] CPU 121a is configured to read and execute a control program from memory device 121c, and to read a recipe from memory device 121c based on input of operation instructions from input / output device 122. CPU 121a is configured to control the flow rate adjustment of various substances (various gases) performed by MFC 241a~241h, the opening and closing of valves 243a~243h, the opening and closing of APC valve 244 and the pressure adjustment of APC valve 244 based on pressure sensor 245, the start and stop of vacuum pump 246, the temperature adjustment of heater 207 based on temperature sensor 263, the rotation and rotation speed adjustment of crystal boat 217 performed by rotating mechanism 267, the lifting and lowering of crystal boat 217 performed by crystal boat elevator 115, and the opening and closing of gate 219s performed by gate opening and closing mechanism 115s, etc., according to the read recipe.

[0032] The controller 121 is configured to install the aforementioned program, recorded and stored in the external memory device 123, onto a computer. The external memory device 123 includes, for example, magnetic disks such as HDDs, optical disks such as CDs, optical disks such as MO drives, semiconductor memory such as USB drives, or SSDs. The memory device 121c or the external memory device 123 constitutes a computer-readable recording medium. Hereinafter, they are collectively referred to as recording media. In this specification, the term "recording media" may refer to only the memory device 121c, only the external memory device 123, or both. Furthermore, the provision of computer programs may also be designed to utilize communication methods such as the Internet or dedicated lines, without using the external memory device 123.

[0033] (2) Substrate processing process Figure 4 is used to illustrate an example of the processing sequence for forming a film on the surface of a wafer 200, which serves as a substrate, using the substrate processing apparatus described above, as a step in the manufacturing process of a semiconductor device. In the following description, the operation of each component constituting the substrate processing apparatus is controlled by the controller 121.

[0034] In the processing order of the sample in this state, Step A1: Supplying a first raw material gas containing the first element to wafer 200; Step A2: Supplying the first reactive gas to wafer 200; The loop containing the first element is performed for the first time (m times, where m is an integer of 1 or 2 or higher), thereby forming the first step of the first layer containing the first element; Step B1: Supplying a second raw material gas containing a first element and a first halogen element to wafer 200; After the first period of supplying the second raw material gas in step B1 has been carried out, step B2 is performed to supply the wafer 200 with a third raw material gas containing the second halogen element and the second element not present in the first layer; Step B3 involves supplying the second reactant gas to wafer 200 after the second period of supplying the third raw material gas in step B2 has been completed; The loop containing the first and second elements is performed a second time (n times, where n is an integer of 1 or 2 or higher), thereby forming the second process of the second layer containing the first and second elements; Perform: thereby forming a film containing element 1 and element 2 on wafer 200.

[0035] In this sample, an example of a charge trap film forming a non-volatile memory cell is explained, using a film containing elements 1 and 2 (hereinafter simply referred to as "film"). A charge trap film, for example, is the ONO film constituting a NAND flash memory, that is, the SiN film in an insulating film composed of three layers: SiO film, SiN film, and SiO film (see Figure 5). In this sample, the case where a SiN film is formed is explained as an example.

[0036] In Figure 4, the first raw material gas, the second raw material gas, and the third raw material gas are denoted as 1, 2, and 3, respectively, and the first reactant gas and the second reactant gas are denoted as i and ii, respectively. Furthermore, P in Figure 4 indicates the purging of the treatment chamber 201. These points are also consistent with those in Figures 6(a) to 8(c).

[0037] In this specification, when the term "wafer" is used, it is intended to refer to the wafer itself, or to a laminate of a wafer and a specified layer or film formed on its surface. When the term "surface of a wafer" is used, it is intended to refer to the surface of the wafer itself, or to the surface of a specified layer, etc., formed on the wafer. When the phrase "forming a specified layer on a wafer" is used, it is intended to refer to forming the specified layer directly on the surface of the wafer itself, or to forming the specified layer on top of layers, etc., formed on the wafer. The term "substrate" is also synonymous with the term "wafer" in this specification.

[0038] As used in this specification, the term "layer" includes at least one of continuous layers and discontinuous layers. For example, the first or second layer described later may include continuous layers, discontinuous layers, or both.

[0039] In this specification, when describing the adsorption or reaction of the first raw material gas or the second raw material gas on the surface of the wafer 200, it includes not only the adsorption or reaction of the gas on the wafer surface without decomposition, but also the adsorption or reaction of the intermediate generated due to the decomposition of the gas or the detachment of its ligand on the surface of the wafer 200.

[0040] (Wafer feeding and crystal boat loading) Once multiple wafers 200 are loaded into the crystal boat 217, the gate 219s is moved, and the lower opening of the manifold 209 is opened. Subsequently, the crystal boat 217 supporting the multiple wafers 200 is lifted by the crystal boat elevator 115 and moved into the processing chamber 201.

[0041] (Pressure and temperature adjustment) After the wafer boat is loaded, the processing chamber 201, i.e., the space where the wafer 200 is located, is evacuated by vacuum pump 246 (pressure reduction evacuation) to achieve the desired pressure (vacuum level). At this time, the pressure in the processing chamber 201 is measured by pressure sensor 245, and the APC valve 244 is controlled by feedback (pressure adjustment) based on this measured pressure information. In addition, the wafer 200 in the processing chamber 201 is heated by heater 207 to achieve the desired processing temperature. At this time, the energization of heater 207 is controlled by feedback based on temperature information detected by temperature sensor 263 to achieve the desired temperature distribution in the processing chamber 201 (temperature adjustment). Furthermore, the rotation of the wafer 200 by rotation mechanism 267 is started. The evacuation in the processing chamber 201, the heating of the wafer 200, and the rotation all continue at least until the processing of the wafer 200 is completed.

[0042] (Step 1 (Process 1)) Then, steps A1 and A2 are executed sequentially.

[0043] [Step A1] In step A1, a first raw material gas is supplied to the wafer 200 in the processing chamber 201.

[0044] Specifically, valve 243a is opened, allowing the first raw material gas to flow into the gas supply pipe 232a. The first raw material gas, with its flow rate adjusted by MFC 241a, is supplied to the processing chamber 201 through nozzle 249a and exhausted through exhaust port 231a. At this time, the first raw material gas is supplied to the wafer 200. Alternatively, valves 243g and 243h can be opened to supply inactive gas into the processing chamber 201 through nozzles 249a and 249b respectively.

[0045] As a processing condition in this step, Processing temperature: 350~800℃, preferably 500~700℃ Processing pressure: 10~1333Pa, preferably 10~133Pa The first feed gas supply flow rate is 0.1~3 slm, preferably 0.1~0.5 slm. The first raw material gas supply time is 1~180 seconds, preferably 10~80 seconds. Inactive gas supply flow rate (per gas supply pipe): 0~20 slm Example

[0046] Furthermore, the notation of numerical ranges such as "350~800℃" in this specification means that the lower and upper limits are included within that range. Therefore, for example, "350~800℃" means "above 350℃ and below 800℃". The same applies to other numerical ranges. Additionally, the term "processing temperature" in this specification refers to the temperature of the wafer 200 or the temperature inside the processing chamber 201, and the term "processing pressure" refers to the pressure inside the processing chamber 201, in other words, the pressure of the space in which the wafer 200 is located. Furthermore, the term "processing time" refers to the duration of the processing. Moreover, when the supply flow rate includes 0 slm, 0 slm means that no substance (gas) is supplied. These also apply to the following descriptions.

[0047] Under the aforementioned processing conditions, a chlorosilane-based gas is supplied to wafer 200 as the first raw material gas, thereby forming a chlorine (Cl)-containing silicon (Si) layer on the surface of wafer 200. The Cl-containing Si layer is formed by the physical or chemical adsorption of molecules of the chlorosilane-based gas on the outermost surface of wafer 200, or by the physical or chemical adsorption of molecules of substances derived from the partial decomposition of the chlorosilane-based gas. The Cl-containing Si layer can also be an adsorption layer (physical adsorption layer or chemical adsorption layer) of molecules of the chlorosilane-based gas or molecules of substances derived from the partial decomposition of the chlorosilane-based gas. In this specification, the Cl-containing Si layer is also simply referred to as the Si layer. The Si layer formed in this step is also referred to as the first Si layer.

[0048] After the first Si-containing layer is formed, valve 243a is closed to stop the supply of the first gas to the processing chamber 201. Then, the processing chamber 201 is evacuated to remove any remaining gases (purged gas) from the processing chamber 201. At this time, valves 243g and 243h are opened to supply inactive gas into the processing chamber 201 through nozzles 249a and 249b. The inactive gas acts as the purged gas.

[0049] As the first raw material gas, a silane-based gas containing Si (e.g., the main element constituting the film formed on wafer 200) as the first element can be used. For example, a gas containing Si and a halogen element, i.e., a halosilane-based gas, can be used. Halogen elements include Cl, fluorine (F), bromine (Br), iodine (I), etc. For example, the aforementioned chlorosilane gas containing Si and Cl can be used as a halosilane-based gas.

[0050] As the first raw material gas, for example, hydrogen-free chlorosilane gases such as tetrachlorosilane (SiCl4), hexachlorodisilazane (Si2Cl6), and octachlorotrisilane (Si3Cl8) can be used.

[0051] As the first raw material gas, for example, a chlorosilane gas containing H such as monochlorosilane (SiH3Cl), dichlorosilane (SiH2Cl2), or trichlorosilane (SiHCl3) can be used.

[0052] As the first raw material gas, for example, hydrogen-free fluorosilane gases such as tetrafluorosilane (SiF4) gas and hexafluorodisilane (Si2F6) gas, hydrogen-free bromosilane gases such as tetrabromosilane (SiBr4) gas and hexabromodisilane (Si2Br6) gas, or hydrogen-free iodosilane gases such as tetraiodosilane (SiI4) gas and hexaiododisilane (Si2I6) gas can be used.

[0053] As the first raw material gas, in addition to chlorosilane-based gases, for example, fluorosilane-based gases containing H such as difluorosilane (SiH2F2) gas and trifluorosilane (SiHF3) gas, or bromosilane-based gases containing H such as dibromosilane (SiH2Br2) gas and tribromosilane (SiHBr3) gas, or iodosilane-based gases containing H such as diiodosilane (SiH2I2) gas and triiodosilane (SiHI3) gas.

[0054] As the first raw material gas, for example, amino-based silane gases such as tetra(dimethylamino)silane (Si[N(CH3)2]4), tri(dimethylamino)silane (Si[N(CH3)2]3H), bis(diethylamino)silane (Si[N(C2H5)2]2H2), bis(tert-butylamino)silane (SiH2[NH(C4H9)]2), and (diisopropylamino)silane (SiH3[N(C3H7)2]) can be used. Furthermore, as the first raw material gas, for example, organic silane gases that exclude amino groups, such as tetraethoxysilane (Si(OC2H5)4), can also be used.

[0055] As the primary raw material gas, one or more of them can be used.

[0056] Nitrogen (N2) gas, or rare gases such as argon (Ar), helium (He), neon (Ne), and xenon (Xe) gas, can be used as inert gases. More than one of these can be used as an inert gas. This also applies to the steps described later.

[0057] [Step A2] After step A1 is completed, the first reaction gas is supplied to the wafer 200 in the processing chamber 201, that is, the first Si-containing layer formed on the wafer 200.

[0058] Specifically, valve 243b is opened, allowing the first reactive gas to flow into the gas supply pipe 232b. The first reactive gas, with its flow rate adjusted by MFC 241b, is supplied to the processing chamber 201 through nozzle 249b and exhausted through exhaust port 231a. At this time, the first reactive gas is supplied to wafer 200. Alternatively, valves 243g and 243h can be opened to supply inactive gas into the processing chamber 201 through nozzles 249a and 249b respectively.

[0059] As a processing condition in this step, Processing pressure: 10~3750Pa, preferably 10~1333Pa The gas supply flow rate for the first reaction is 1~10 slm, preferably 3~6 slm. The gas supply time for the first reaction is 1 to 180 seconds, preferably 10 to 60 seconds. Other processing conditions can be set to the same conditions as in step A1.

[0060] Under the conditions described above, a first reactant gas is supplied to wafer 200, thereby modifying at least a portion of the first Si-containing layer formed on wafer 200. For example, when a hydrogen nitride gas containing nitrogen (N) and H as the third element is used as the first reactant gas, at least a portion of the first Si-containing layer formed on wafer 200 is nitrided, and a silicon nitride layer (SiN layer) containing Si and N as the third element is formed on the outermost surface of wafer 200.

[0061] After the SiN layer is formed, valve 243b is closed to stop the supply of the first reaction gas to the processing chamber 201. Then, the gas and other gases remaining in the processing chamber 201 are removed from the processing chamber 201 by means of the purging procedure in step A1.

[0062] As the first reacting gas, a nitriding gas (nitriding agent) can be used, for example. As the first reacting gas, hydrogen nitriding gases such as ammonia (NH3), diimine (N2H2), hydrazine (N2H4), and N3H8 can be used, for example. One or more of these can be used as the first reacting gas.

[0063] [Number of times stipulated for implementation] The above steps A1 and A2 are performed asynchronously for the first time (m times, where m is an integer of 1 or 2, preferably an integer of 1 to 10), thereby forming a SiN layer as the first layer on the surface of wafer 200. The above cycle is preferably repeated multiple times. That is, it is preferable to set the thickness of the SiN layer formed in each cycle to be thinner than the desired film thickness, and repeat the above cycle multiple times until the film thickness of the first layer formed by depositing the SiN layer reaches the desired film thickness.

[0064] (Second Process / Treatment) Then, proceed with steps B1 to B3 in sequence.

[0065] [Step B1] In step B1, a second raw material gas containing a first element and a first halogen element is supplied to the wafer 200 in the processing chamber 201, that is, the first layer formed on the wafer 200.

[0066] Specifically, valve 243c is opened, allowing the second raw material gas to flow into the gas supply pipe 232c. The second raw material gas, with its flow rate adjusted by MFC 241c, is supplied to the processing chamber 201 through nozzle 249a and exhausted through exhaust port 231a. At this time, the second raw material gas is supplied to wafer 200. Alternatively, valves 243g and 243h can be opened to supply inactive gas into the processing chamber 201 through nozzles 249a and 249b respectively.

[0067] As a processing condition in this step, The second raw material gas supply flow rate is 0.1~3 slm, preferably 0.1~0.5 slm. The second raw material gas supply time (first period): 1~180 seconds, preferably 10~30 seconds. Other processing conditions can be set to be the same as those in step A1. However, in order to adjust the composition ratio of the (incorporated) second element in the second layer formed in this process, the processing conditions in this step can also be different from those in step A1. For example, the supply flow rate of the second raw material gas can be set to be smaller than the supply flow rate of the first raw material gas, thereby increasing the composition ratio of the second element. In addition, for example, the supply time of the second raw material gas can be set to be shorter than the supply time of the first raw material gas, thereby increasing the composition ratio of the second element.

[0068] Under the aforementioned processing conditions, a second raw material gas, for example containing Si as the first element and a first halogen element, is supplied to the wafer 200. This allows the formation of a Si-containing layer, with Si and terminals of the first halogen element formed on its surface, on the SiN layer, which is the first layer formed on the wafer 200. In this specification, the terminals of the first halogen element are also referred to as first halogen terminals. Furthermore, the Si-containing layer formed in this step is also referred to as the second Si-containing layer.

[0069] After the second Si-containing layer is formed by supplying the second raw material gas during the first period, valve 243c is closed to stop the supply of the second raw material gas to the processing chamber 201. Then, the gas remaining in the processing chamber 201 is removed from the processing chamber 201 through a purging process similar to that in step A1. However, the purging step of the processing chamber 201 between steps B1 and B2 can also be omitted. That is, steps B1 and B2 can also be performed continuously.

[0070] As a second raw material gas, a halosilane gas containing Si (the main element constituting the film formed on wafer 200) as the first element and a first halogen element can be used. The first halogen element includes Cl, F, Br, I, etc. As a halosilane gas, a chlorosilane gas containing Si and Cl can be used, for example.

[0071] As the second raw material gas, a gas containing one or more of the halosilane-based gases mentioned as examples of the first raw material gas can be used. The second raw material gas is preferably the same as the first raw material gas, but a different gas can also be used. However, the second raw material gas is preferably a gas that does not contain hydrogen (H).

[0072] [Step B2] In step B2, a third raw material gas containing a second halogen element and a second element not present in the first layer is supplied to the wafer 200 in the processing chamber 201, that is, the second Si-containing layer on the wafer 200.

[0073] Specifically, valve 243d is opened, allowing the third raw material gas to flow into the gas supply pipe 232d. The third raw material gas, with its flow rate adjusted by MFC 241d, is supplied to the processing chamber 201 through nozzle 249a and exhausted through exhaust port 231a. At this time, the third raw material gas is supplied to wafer 200. Alternatively, valves 243g and 243h can be opened to supply inactive gas into the processing chamber 201 through nozzles 249a and 249b respectively.

[0074] As a processing condition in this step, The third raw material gas supply flow rate is 0.05~6 slm, preferably 0.5~2 slm. The third raw material gas supply time (second period): 2~60 seconds, preferably 4~30 seconds. Other processing conditions can be set to the same conditions as in step A1.

[0075] Under the aforementioned processing conditions, a third raw material gas containing a second halogen element and a specified second element is supplied to the wafer 200. This allows titanium (Ti), for example, a second element, to be adsorbed in regions (adsorption sites) on the second Si-containing layer where the first halogen terminal is not formed, thus forming a second halogen terminal. In this way, for example, Ti can be added (doped) to the second Si-containing layer. This transforms the second Si-containing layer formed on the wafer 200 in step B1 into a second Si-containing layer doped with Ti. In this specification, the second halogen terminal is also referred to as a second halogen terminal.

[0076] After the supply of the third raw material gas is carried out in the second period and a second Si-containing layer doped with Ti is formed, valve 243d is closed to stop the supply of the third raw material gas to the processing chamber 201. Then, by means of the purging process in step A1, the gas and other gases remaining in the processing chamber 201 are removed from the processing chamber 201.

[0077] As a third feedstock gas, for example, a halogenated titanium halide gas containing a second halogen element and Ti as the second element can be used. The second halogen element includes Cl, F, Br, I, etc. The second halogen element and the first halogen element can be the same element or different elements. If the second element and the first element are different elements, the third feedstock gas is different from both the first and second feedstock gases.

[0078] As a third raw material gas, for example, hydrogen-free titanium halide gases such as titanium tetrachloride (TiCl4), titanium tetrafluoroethylene (TiF4), titanium tetrabromo (TiBr4), and titanium tetraiodide (TiI4) can be used.

[0079] As a third raw material gas, for example, titanium halide gases containing H such as titanium monochloride (TiH3Cl), titanium difluoride (TiH2F2), titanium dibromo (TiH2Br2), and titanium diiodo (TiH2I2) can be used.

[0080] One or more of these can be used as the third feed gas. The third feed gas is preferably a gas that does not contain H.

[0081] [Step B3] In step B3, a second reaction gas is supplied to the wafer 200 in the processing chamber 201, that is, the second Si-containing layer on the wafer 200 doped with Ti.

[0082] Specifically, valve 243f is opened, allowing the second reactive gas to flow into gas supply pipe 232f. The flow rate of the second reactive gas is adjusted by MFC 241f, and it is supplied to processing chamber 201 through nozzle 249b and exhausted through exhaust port 231a. At this time, the second reactive gas is supplied to wafer 200. Alternatively, valves 243g and 243h can be opened to supply inactive gas to processing chamber 201 through nozzles 249a and 249b respectively.

[0083] As a processing condition in this step, Processing pressure: 10~3750Pa, preferably 10~1333Pa The gas supply flow rate for the second reaction is 1~10 slm, preferably 3~6 slm. The second reaction gas supply time is 1-180 seconds, preferably 10-60 seconds. Other processing conditions can be set to the same conditions as in step A1.

[0084] Under the aforementioned conditions, a second reactant gas is supplied to wafer 200, thereby modifying at least a portion of the Ti-doped second Si-containing layer formed on wafer 200. For example, when a hydrogen nitride-based gas containing N and H as the third element is used as the second reactant gas, as with the first reactant gas, at least a portion of the Ti-doped second Si-containing layer formed on wafer 200 is nitrided, forming a SiN layer doped with Ti and containing N as the third element.

[0085] After the SiN layer doped with Ti is formed, valve 243f is closed to stop the supply of the second reaction gas to the processing chamber 201. Then, the gas and other gases remaining in the processing chamber 201 are removed from the processing chamber 201 by means of the purging procedure in step A1.

[0086] As the second reactant gas, one or more gases, including those listed as examples of the first reactant gas, can be used. The second reactant gas is preferably the same as the first reactant gas, but a different gas can also be used. The second reactant gas is preferably a gas that reacts with either the first or second halogen terminal.

[0087] [Number of times stipulated for implementation] The above steps B1 to B3 are performed asynchronously for a second time (n times, where n is an integer of 1 or 2, preferably an integer of 1 to 10), thereby forming a Ti-doped SiN layer as a second layer on, for example, the first SiN layer. The above cycle is preferably repeated multiple times. That is, it is preferable to set the thickness of the Ti-doped SiN layer formed in each cycle to be thinner than the desired film thickness, and repeat the above cycle multiple times until the film thickness of the second layer formed by depositing the Ti-doped SiN layer reaches the desired film thickness.

[0088] The cycle comprising the first and second steps described above is performed a predetermined number of times (p times, where p is an integer of 1 or 2 or more, preferably an integer of 2 or more, i.e., the third time), thereby forming a Ti-doped SiN film (hereinafter simply referred to as "SiN film") on the wafer 200, for example, consisting of a first SiN layer (i.e., an undoped SiN layer) and a second Ti-doped SiN layer. The Ti-doped SiN film can also be described as a film containing a first element and a third element doped with a second element. In this embodiment, it is preferable to set the thickness of the SiN film formed in each cycle to be thinner than the desired film thickness, and to repeat the above cycle several times until the thickness of the SiN film formed by the deposition of the SiN film reaches the desired thickness.

[0089] The ratio (i.e., n / m) of the first number (m) in the first process to the second number (n) in the second process is preferably set (i.e. selected) so that the composition ratio of Ti in the SiN film is a specified ratio.

[0090] The supply amount of the second raw material gas in step B1 is preferably set such that the Ti composition ratio in the Ti-doped SiN layer is a predetermined ratio. Specifically, at least one of the supply flow rate or the supply time of the second raw material gas in step B1 is preferably set such that the Ti composition ratio in the Ti-doped SiN layer is a predetermined ratio.

[0091] The thickness of the first SiN layer is preferably such that the Ti contained in the Ti-doped SiN layer (which is the second SiN layer) diffuses throughout the thickness direction of the adjacent SiN layers (thickness or less).

[0092] (After exhaust and atmospheric pressure recovery) After step B3 is completed, an inert gas, acting as a purge gas, is supplied into the processing chamber 201 from nozzles 249a and 249b, and exhaust is carried out from exhaust port 231a. This purges the processing chamber 201, removing any residual gases or reaction byproducts. Subsequently, the environment within the processing chamber 201 is replaced with an inert gas, and the pressure within the processing chamber 201 is restored to atmospheric pressure.

[0093] (Crystal boat unloading and wafer output) Subsequently, the cap 219 is lowered by the crystal boat elevator 115, and the lower end of the manifold 209 is opened. Then, the processed wafer 200, supported by the crystal boat 217, is moved from the lower end of the manifold 209 to the outside of the reaction tube 203. After the crystal boat is unloaded, the lower end opening of the manifold 209 is sealed by the gate 219s. The processed wafer 200, after being moved to the outside of the reaction tube 203, is removed from the crystal boat 217.

[0094] (3) According to the effect of this state. According to this state, one or more effects can be obtained as shown below.

[0095] (a) A cycle is performed comprising a first step without the step of supplying the gas containing the second element, and a second step with the step of supplying the gas containing the second element. This allows for improved controllability of the composition ratio of the second element incorporated into the membrane (i.e., the composition ratio of the second element relative to all elements constituting the membrane). In particular, in regions where the composition ratio of the second element is low (e.g., less than 5 atomic%, preferably less than 1 atomic%), fine adjustments to the composition ratio of the second element can be easily made. This allows for the easy acquisition of desired membrane properties, such as desired charge trapping properties.

[0096] (b) The cycle including the first step and the second step is performed more than twice, thereby improving the controllability of the composition ratio of the second element added to the membrane.

[0097] (c) In step B1, a gas free of H, i.e., the second feed gas, is supplied. This reduces the number of H terminals (adsorption sites) present on the surface of the second Si-containing layer that can be adsorbed by the third feed gas before its supply. This suppresses the adsorption of the second element contained in the third feed gas onto the second Si-containing layer. As a result, the composition ratio of the second element in the film can be controlled to be lower.

[0098] (d) In step B2, a gas free of H, i.e., a gas that will not react with the halogen terminal (the third feed gas), is supplied. This suppresses the detachment of the first halogen element from the second Si-containing layer where the first halogen terminal is formed after the second feed gas is supplied. This also suppresses the adsorption (doping) of the second element contained in the third feed gas into the second Si-containing layer. As a result, the composition ratio of the second element in the film can be controlled to be lower.

[0099] (e) In step B3, a second reactant gas is supplied that reacts with either the first halogen terminal or the second halogen terminal, thereby causing the first halogen element or the second halogen element bonded to the first element to detach from the second Si-containing layer doped with the second element. As a result, impurities such as the first halogen element or the second halogen element in the film can be reduced. Furthermore, by causing the first halogen element or the second halogen element bonded to the first element to detach from the second Si-containing layer doped with the second element and forming a dangling bond of the first element, the adsorption of the second feed gas can be promoted in step B1 of the next cycle. As a result, film formation can be promoted.

[0100] (f) The first and second raw material gases are the same gas, thereby making the composition of the first layer (excluding the second element) similar to that of the second layer. That is, the properties of the membrane can be made nearly uniform in the thickness direction except for the second element.

[0101] (g) The first and second reacting gases are the same gas, thereby making the composition of the first layer (excluding the second element) similar to that of the second layer. That is, the properties of the membrane can be made nearly uniform in the thickness direction except for the second element.

[0102] (h) The ratio of the first number of times in the first process to the second number of times in the second process is set such that the composition ratio of the second element in the membrane becomes a predetermined ratio. In this way, by adjusting the ratio of the number of layers of the first layer without the second element to the number of layers of the second layer containing the second element, the composition ratio of the second element in the membrane can be controlled to a desired value.

[0103] (i) The supply amount of the second raw material gas in step B1 is set such that the composition ratio of the second element in the second layer is a predetermined ratio. For example, by adjusting the supply amount of the second raw material gas in step B1, the ratio of adsorption sites (i.e., those not terminated by the first halogen) on the surface of wafer 200 that can be adsorbed by the third raw material gas (specifically, the second element) can be adjusted. This allows control of the composition ratio of the second element in the second layer. Specifically, for example, in step B1, at least one of reducing the supply flow rate of the second raw material gas or shortening the supply time of the second raw material gas is performed, thereby increasing the ratio of adsorption sites of the second element on the surface of wafer 200. This increases the adsorption amount of the second element and increases the composition ratio of the second element in the film. Alternatively, for example, in step B1, at least one of increasing the supply flow rate of the second raw material gas or lengthening the supply time of the second raw material gas is performed, thereby decreasing the ratio of adsorption sites of the second element on the surface of wafer 200. This reduces the amount of the second element adsorbed and decreases the composition ratio of the second element in the membrane.

[0104] (j) The thickness of the first layer is such that the second element contained in the second layer can diffuse throughout the thickness direction of the adjacent first layer (below the thickness), thereby enabling the second element to diffuse throughout the entire membrane (the entire thickness direction of the membrane). The distribution of the composition ratio in the thickness direction of the membrane can be controlled.

[0105] (k) By setting the first (m) and second (n) diffusion times to between 1 and 10, the second element can be diffused uniformly along the thickness direction of the membrane, resulting in a substantially uniform composition ratio of the second element. If the first and second diffusion times exceed 10, the diffusion of the second element cannot extend along the thickness direction of the membrane, and the composition ratio of the second element may become skewed.

[0106] (4) Variations The substrate processing sequence in this sample can be changed as shown in the following variations. These variations can be combined arbitrarily. Unless otherwise specified, the processing procedures and conditions in each step of each variation are the same as those in each step of the substrate processing sequence described above.

[0107] (Variation Example 1) As shown in Figure 6(a), in addition to the process of performing a first cycle containing the first and second processes, a second cycle containing the first and second processes can also be performed. In this case, the ratio of the second number of times (n times) relative to the first number of times (m times) in the first cycle can be different from the ratio of the second number of times (n' times) relative to the first number of times (m' times) in the second cycle. That is, it can be designed so that the ratio of the second number of times relative to the first number of times changes depending on the execution number of the cycle containing the first and second processes. Furthermore, the number of times the first cycle is performed (p times) and the number of times the second cycle is performed (p' times) can be the same or different. m, m', n, n', p, and p' are all integers of 1 or more.

[0108] Specifically, for example, the second cycle can be performed after the first cycle, and the ratio of the second cycle to the first cycle (n / m) in the first cycle can be set to be greater than the ratio of the second cycle to the first cycle (n' / m'). That is, the composition ratio of the second element in the membrane formed in the preceding cycle (first cycle) can be set to be greater than the composition ratio of the second element in the membrane formed in the subsequent cycle (second cycle). Furthermore, for example, the number of times the second cycle is performed (p' times) can be set to be greater than the number of times the first cycle is performed (p times).

[0109] In addition to the first and second cycles, a third cycle that includes the first and second processes can also be included. In this case, the ratio of the second number of times relative to the first number of times in the first, second, and third cycles can also be designed to be different from each other.

[0110] According to this modified example, the same effect as that obtained by the above-described state can be obtained. In this modified example, it is even possible to form a plurality of layers with different composition ratios of the second element. In this way, the composition ratio of the second element can be varied along the thickness direction of the film, thereby establishing a composition ratio gradient.

[0111] Furthermore, in this modified example, the ratio (n / m) of the second iteration relative to the first iteration in the first cycle is set to be larger than the ratio (n' / m') of the second iteration relative to the first iteration in the second cycle. This allows for the formation of a charge trapping film on a barrier film in a manufacturing process of non-volatile memory cells, such as NAND flash memory. Specifically, this process enables the formation of a layer with a high composition ratio of the second element and a high charge trapping density on the side close to the barrier film, while a layer with a low composition ratio of the second element and a low charge trapping density is formed on the side farther away (see Figure 9). This improves the electrical characteristics of the charge trapping film.

[0112] Furthermore, in this modified example, the number of times the second cycle is performed (p' times) is set to be greater than the number of times the first cycle is performed (p times), thereby increasing the thickness of the layer with a smaller composition ratio of the second element compared to the thickness of the layer with a larger composition ratio of the second element (see Figure 9).

[0113] Furthermore, in this modified example, the ratio of the second number to the first number in the first, second, and third cycles is gradually changed, thereby allowing the composition ratio of the second element to change in stages along the thickness direction of the film.

[0114] (Variation Example 2) As shown in Figure 6(b), step B1 can also be designed to include a period after the first period, during which the supply of the third raw material gas and the supply of the second raw material gas are continued simultaneously. That is, steps B1 and B2 can also be designed to have a period during which the second and third raw material gases are supplied at the same time. In addition, the notation 2+3 shown in Figure 6(b) indicates the overlap between the supply period of the second raw material gas (the execution period of step B1) and the supply period of the third raw material gas (the execution period of step B2). This is also true for the notation 2+4 shown in Figure 7(b).

[0115] In this variation, the supply amount of the second raw material gas in the first period (specifically, at least one of the length of the first period in step B1 or the supply flow rate of the second raw material gas in the first period) can also be set such that the composition ratio of the second element in the second layer is a predetermined ratio.

[0116] According to this variation, the same effect as that obtained by the above-described manner can be achieved.

[0117] (Variation Example 3) Alternatively, it can be designed to use a gas without H as the second raw material gas, and include the cycle of steps B1, B2, and B3 described above, with step B4 (see Figure 7(a)) before supplying the third raw material gas, which further includes supplying a fourth raw material gas containing the first element, the third halogen element, and H. In Figure 7(a), the fourth raw material gas is denoted as 4. This is also true in Figures 7(b) and 8(b) described later.

[0118] As the second raw material gas in this variation, one or more of the H-free silane-based gases listed in the above-described state samples can be used.

[0119] As the fourth raw material gas, for example, a halosilane gas containing Si as the first element, a third halogen element, and H can be used. The third halogen element includes Cl, F, Br, I, etc. Furthermore, the third halogen element and the first or second halogen element can be the same element or different elements. As the fourth raw material gas, for example, one or more of the H-containing halosilane gases listed in the above-described forms can be used.

[0120] In this modified example, the ratio of the supply amount of the second raw material gas to the supply amount of the fourth raw material gas can also be adjusted to adjust the composition ratio of the second element contained in the second layer. Specifically, at least one of the supply flow rate or supply time of one of the second and fourth raw material gases can be adjusted to adjust the composition ratio of the second element contained in the second layer.

[0121] In this variation, the ratio of the supply of the second raw material gas to the supply of the fourth raw material gas can also be designed to change based on the number of times the cycle including the first and second processes is executed (i.e., based on the number of times the cycle is executed).

[0122] According to this modified example, the same effect as that obtained by the above-described state can be obtained. In this modified example, before the supply of the third raw material gas, a fourth raw material gas that can form adsorption sites for the third raw material gas (specifically the second element), i.e., H-terminals, is supplied to the surface of the wafer 200, thereby increasing the composition ratio of the second element in the film.

[0123] Furthermore, in this modified example, the ratio of the supply amount of the second raw material gas to the supply amount of the fourth raw material gas is adjusted, thereby adjusting the composition ratio of the second element contained in the second layer.

[0124] Furthermore, in this modified example, the ratio of the supply amount of the second raw material gas to the supply amount of the fourth raw material gas is changed according to the number of cycles, thereby enabling the composition ratio of the second element to change in the thickness direction of the membrane.

[0125] Furthermore, although this variation illustrates an example of performing a drain between step B1 and step B4, it can also be designed, as shown in Figure 7(b), to have at least a portion of the execution period of step B1 and the execution period of step B4 overlap. The same effect as the above-described variation can be achieved in this variation.

[0126] (Variation Example 4) As shown in Figure 8(a), it can also be designed to include: a third process, in which the cycle of step C1, which includes supplying the second raw material gas to the wafer 200, step C2, which includes supplying the second reactant gas after a third period of supplying the second raw material gas in step C1, and step C3, which includes supplying the third raw material gas after a fourth period of supplying the second reactant gas in step C2, is performed a third time (r times), thereby forming a third layer containing the first and second elements; and the cycle of the first, second, and third processes is performed a predetermined number of times (p times), thereby forming a film containing the first and second elements composed of the first, second, and third layers on the wafer 200. r and p are integers of 1 or 2 or more.

[0127] In this modified example, the ratio of the first (m), second (n), and third (r) iterations can also be set to ensure that the composition ratio of the second element in the membrane is a predetermined ratio. Alternatively, the first (m) iteration can be set to zero according to the desired composition ratio of the second element.

[0128] According to this modified example, the same effect as that obtained by the above-described state can be obtained. In this modified example, in the third step, the halogen terminals formed on the outermost surface of wafer 200 by the supply of the second raw material gas are removed by the reactant gas, thereby increasing the number of adsorption sites (e.g., N-H terminals) available for adsorption by the third raw material gas. Therefore, the adsorption probability of the third raw material gas is increased in the third step compared to the second step, and the composition ratio of the second element contained in the third layer can be increased compared to the second layer.

[0129] Furthermore, according to this modified example, by adjusting the ratio of the number of layers of the first layer (which does not contain the second element) to the number of layers of the second and third layers (which contain the second element in different composition ratios), the composition ratio of the second element in the membrane can be controlled to a desired value.

[0130] (Variation Example 5) As shown in Figure 8(b), the design can also include: a third step, in which a cycle is performed for a third number of times (r times, where r is an integer of 1 or 2 or more) of the following steps: step D1, which includes supplying a fourth raw material gas containing the first element, the third halogen element, and H; step D2, which includes supplying a third raw material gas after a first period of supplying the fourth raw material gas in step D1; and step D3, which includes supplying a second reactant gas after a second period of supplying the third raw material gas in step D2), thereby forming a third layer containing the first element and the second element; and the cycle including the first step, the second step, and the third step is performed, thereby forming a film containing the first element and the second element composed of the first layer, the second layer, and the third layer on the wafer 200. For example, one or more of the H-containing halosilane gases listed in the above-described embodiments can be used as the fourth raw material gas.

[0131] In this modified example, the ratio of the first (m), second (n), and third (r) iterations can also be set to ensure that the composition ratio of the second element in the membrane is a predetermined ratio. Alternatively, the first (m) iteration can be set to zero according to the desired composition ratio of the second element.

[0132] According to this modified example, the same effect as that obtained by the above-described state can be obtained. In this modified example, in the third process, before supplying the third raw material gas, H terminals that can be adsorbed by the third raw material gas can be formed on the surface of the wafer 200. Therefore, compared with the second process, the adsorption rate of the third raw material gas will be increased, and the composition ratio of the second element contained in the third layer can be increased compared with the second layer.

[0133] Furthermore, according to this modified example, by adjusting the ratio of the number of layers of the first layer (which does not contain the second element) to the number of layers of the second and third layers (which contain the second element in different composition ratios), the composition ratio of the second element in the membrane can be controlled to a desired value.

[0134] (Variation Example 6) As shown in Figure 8(c), it can also be designed to include: a third step, performing the cycle including steps A1 and A2 for a third number of times (s times) to form a third layer containing the first element; and a fourth step, performing the cycle including step C1 (supplying the second raw material gas), step C2 (supplying the second reactant gas after the third period of supplying the second raw material gas in step C1), and step C3 (supplying the third raw material gas after the fourth period of supplying the second reactant gas in step C2) for a fourth number of times (t times) to form a fourth layer containing the first and second elements; performing the first cycle including the first and second steps, and the second cycle including the third and fourth steps, thereby forming a film containing the first and second elements composed of the first, second, third, and fourth layers on the wafer 200. s and t are integers of 1 or 2 or more.

[0135] According to this modified example, the same effect as that obtained by the above-described state can be obtained. In this modified example, in the fourth step, similar to the third step in modified example 4 above, the adsorption probability of the third raw material gas is increased compared to the second step, thereby increasing the composition ratio of the second element contained in the fourth layer compared to the second layer. Therefore, by further performing a second cycle of the fourth step, the composition ratio of the second element can be changed in the thickness direction of the film.

[0136] <Other forms disclosed herein> The form of this disclosure has been specifically described above. However, this disclosure is not limited to the form described above, and various changes may be made without departing from its purpose.

[0137] In this disclosure, for example, the first and second reactant gases can be oxidizing gases such as oxygen (O2), ozone (O3), water vapor (H2O), nitric oxide (NO), nitrous oxide (N2O), hydrogen peroxide (H2O2), hydrogen (H2) + oxygen (O2), H2 + ozone (O3), etc. (i.e., gases containing oxygen (O) as the third element), or gases containing hydrogen (H) such as NH3, hydrogen (H2), H2 + O2. The presence of hydrogen-containing gases may partially overlap with oxidizing gases or hydrogen nitride-based gases. Furthermore, the description of "H2 + O2" as two gases in this specification refers to a mixture of H2 and O2 gases. The same effect as the aforementioned sample can be obtained in this sample.

[0138] In this disclosure, it is preferred, for example, that at least one of the first element and the second element is a metallic element or a half-metallic element. The term "half-metallic element" in this specification, excluding Si, refers to boron (B), germanium (Ge), arsenic (As), antimony (Sb), and tellurium (Te). As metallic elements, for example, excluding Ti, zirconium (Zr), hafnium (Hf), tantalum (Ta), niobium (Nb), aluminum (Al), molybdenum (Mo), and tungsten (W) can be used. As the first, second, and third raw material gases, for example, gases containing halides of the aforementioned metallic or half-metallic elements can be used. One or more of these can be used as the first, second, and third raw material gases. However, the first element and the second element are metallic or half-metallic elements that are different from each other. The same effects as those described in the above-described sample can also be obtained in this sample.

[0139] In this disclosure, examples of films formed include half-metal nitride films doped with the aforementioned metal elements (e.g., SiN films doped with the aforementioned metal elements). The film formed can also be a metal nitride film doped with a half-metal element (e.g., titanium nitride films (TiN films) doped with the aforementioned half-metal element). The film formed can also be a metal nitride film doped with a metal element (e.g., TiN films doped with the aforementioned metal element). The film formed can also be a half-metal nitride film doped with a half-metal element (e.g., SiN films doped with the aforementioned half-metal element). Furthermore, an oxide film can be formed instead of a nitride film. The same effects as the aforementioned samples can be obtained in this sample.

[0140] In this disclosure, for example, the first number (m times) and the second number (n times) can also be 11 or more. It can also be designed so that the first number and the second number are set to 11 or more, thereby causing the composition ratio of the second element to be biased in the thickness direction of the film, and forming layers with different composition ratios of the second element.

[0141] This disclosure is applicable, for example, to the formation of films using a leaf-type substrate processing apparatus that processes one or more substrates at a time. Furthermore, this disclosure is applicable to the formation of films using a substrate processing apparatus with a cold-wall type processing furnace. Additionally, this disclosure is applicable, for example, to the activation of gases by plasma generated inside or outside the processing chamber 201, or to the activation of gases by irradiating them with electromagnetic waves using lamps or the like.

[0142] Even when using these substrate processing devices, each processing procedure and processing condition can be performed in the same manner as the above-described state or modified example, and the same effect as the above-described state or modified example can be obtained.

[0143] The above-mentioned forms or variations can be used in combination. The processing procedures and conditions at this time can be set to be the same as those of the above-mentioned forms or variations.

[0144] 200: Wafer (substrate)

Claims

1. A substrate processing method comprising: performing a first step comprising: (a-1) supplying a first raw material gas containing a first element to the substrate; (a-2) supplying a first reaction gas to the substrate; and performing a cycle for a first number of times to form a first layer containing the first element; and performing a second step comprising: (b-1) supplying a second raw material gas containing the first element and a first halogen element to the substrate; (b-2) after the first period of supplying the second raw material gas in (b-1) has been performed, supplying a third raw material gas containing a second halogen element and a second element not present in the first layer to the substrate; and (b-3) after the second period of supplying the third raw material gas in (b-2) has been performed, supplying a second reaction gas to the substrate; and performing a second step for a second number of times to form a second layer containing the first element and the second element; thereby forming a film containing the first element and the second element on the substrate. The aforementioned first element and the aforementioned second element are metallic or semi-metallic elements, and the aforementioned first reactant gas and the aforementioned second reactant gas are gases containing the third element, namely nitrogen or oxygen.

2. The substrate processing method as described in claim 1, wherein, The aforementioned third raw material gas is a gas that does not contain hydrogen.

3. The substrate processing method as described in claim 1, wherein, The aforementioned second raw material gas is a gas that does not contain hydrogen.

4. The substrate processing method as described in claim 1, wherein, The first raw material gas and the second raw material gas mentioned above are the same gas.

5. The substrate processing method as described in claim 1, wherein, The first reactant gas and the second reactant gas mentioned above are the same gas.

6. The substrate processing method as described in claim 1, wherein, The aforementioned membrane is a membrane containing the aforementioned third element.

7. The substrate processing method as described in claim 1, wherein, The ratio of the first number to the second number is set such that the composition ratio of the second element in the membrane is a predetermined ratio.

8. The substrate processing method as described in claim 1, wherein, At least one of the supply flow rate or supply time of the aforementioned second raw material gas in (b-1) is set such that the composition ratio of the aforementioned second element in the aforementioned second layer becomes a predetermined ratio.

9. The substrate processing method as described in claim 1, wherein, The aforementioned membrane is formed by performing the cycle comprising the first and second steps for a third time, two or more times.

10. The substrate processing method as described in claim 1, wherein, The aforementioned membrane is a charge trapping membrane for non-volatile memory cells.

11. The substrate processing method as described in claim 1, wherein, The thickness of the first layer is the thickness that allows the second element contained in the second layer to diffuse throughout the thickness direction of the adjacent first layer.

12. The substrate processing method as described in claim 1, wherein, It has the following features: performing a process that includes the first process and the second process described above; performing a process that includes the first process and the second process described above; the ratio of the second number of times in the first cycle to the first number of times is different from the ratio of the second number of times in the second cycle to the first number of times.

13. The substrate processing method as described in claim 1, wherein, In (b-1), after the first period mentioned above, there is a period in which the supply of the third raw material gas is supplied while the supply of the second raw material gas continues.

14. The substrate processing method as described in claim 1, wherein, The aforementioned second raw material gas is a hydrogen-free gas, and includes the aforementioned cycles (b-1), (b-2), and (b-3), and further includes: (b-4) a process of supplying the aforementioned substrate with a fourth raw material gas containing the aforementioned first element, the third halogen element, and hydrogen before supplying the aforementioned third raw material gas to the aforementioned substrate.

15. The substrate processing method as described in claim 1, wherein, Furthermore, it includes: a third step comprising: (c-1) supplying the aforementioned second raw material gas to the aforementioned substrate; (c-2) after the supply of the aforementioned second raw material gas in (c-1) has been carried out for a third period, supplying the aforementioned second reactant gas to the aforementioned substrate; (c-3) after the supply of the aforementioned second reactant gas in (c-2) has been carried out for a fourth period, supplying the aforementioned third raw material gas to the aforementioned substrate; and performing a cycle comprising the aforementioned first step, the aforementioned second step, and the aforementioned third step, thereby forming a film containing the aforementioned first element and the aforementioned second element on the aforementioned substrate.

16. The substrate processing method as described in claim 1, wherein, Furthermore, it includes: a third step comprising: (d-1) supplying the aforementioned substrate with a fourth raw material gas containing the aforementioned first element, the third halogen element, and hydrogen; (d-2) after the supply of the aforementioned fourth raw material gas in (d-1) has been carried out for a first period, supplying the aforementioned third raw material gas to the aforementioned substrate; (d-3) after the supply of the aforementioned third raw material gas in (d-2) has been carried out for a second period, supplying the aforementioned second reactant gas to the aforementioned substrate; and performing a third cycle comprising the aforementioned first step, the aforementioned second step, and the aforementioned third step, thereby forming a film containing the aforementioned first element and the aforementioned second element on the aforementioned substrate.

17. The substrate processing method as described in claim 1, wherein, The method comprises: a third process that performs a third cycle including (a-1) and (a-2) a third time to form a third layer containing the aforementioned first element; a fourth process that performs a fourth cycle including: (c-1) supplying the aforementioned second raw material gas to the aforementioned substrate; (c-2) after the supply of the aforementioned second raw material gas in (c-1) has been performed for a third time, supplying the aforementioned second reactant gas to the aforementioned substrate; (c-3) after the supply of the aforementioned second reactant gas in (c-2) has been performed for a fourth time, supplying the aforementioned third raw material gas to the aforementioned substrate; a fourth process that performs a first cycle including the aforementioned first process and the aforementioned second process; and a fourth process that performs a second cycle including the aforementioned third process and the aforementioned fourth process to form a film containing the aforementioned first element and the aforementioned second element on the aforementioned substrate.

18. A method for manufacturing a semiconductor device, comprising: performing a cycle comprising: (a-1) supplying a first raw material gas containing a first element to a substrate; and (a-2) supplying a first reactant gas to the substrate for a first number of times, thereby forming a first layer containing the first element; and performing a cycle comprising: (b-1) supplying a second raw material gas containing the first element and a first halogen element to the substrate; (b-2) after the supply of the second raw material gas in (b-1) has been performed for a first period, supplying a third raw material gas containing a second halogen element and a second element not present in the first layer to the substrate; and (b-3) after the supply of the third raw material gas in (b-2) has been performed for a second period, supplying a second reactant gas to the substrate for a second number of times, thereby forming a second layer containing the first element and the second element; thereby forming a film containing the first element and the second element on the substrate. The aforementioned first element and the aforementioned second element are metallic or semi-metallic elements, and the aforementioned first reactant gas and the aforementioned second reactant gas are gases containing the third element, namely nitrogen or oxygen.

19. A program, by instructing a substrate processing apparatus via a computer, to perform: a first process comprising: (a-1) supplying a substrate with a first raw material gas containing a first element; (a-2) supplying the substrate with a first reaction gas; a first number of cycles, thereby forming a first layer containing the first element; a second process comprising: (b-1) supplying the substrate with a second raw material gas containing the first element and a first halogen element; (b-2) after the supply of the second raw material gas in (b-1) has been performed for a first period, supplying the substrate with a third raw material gas containing a second halogen element and a second element not present in the first layer; (b-3) after the supply of the third raw material gas in (b-2) has been performed for a second period, supplying the substrate with a second reaction gas; a second number of cycles, thereby forming a second layer containing the first element and the second element; This is used to perform the procedure of forming a film containing the first element and the second element on the aforementioned substrate, wherein the first element and the second element are metallic or semi-metallic elements, and the first reactant gas and the second reactant gas are gases containing the third element, namely nitrogen or oxygen.

20. A substrate processing apparatus comprising: a gas supply system for supplying a substrate with a first raw material gas containing a first element, a second raw material gas containing the first element and a first halogen element, a third raw material gas containing a second halogen element and a second element, a first reactant gas, and a second reactant gas; and a control unit configured to control the gas supply system to perform: a first process comprising: (a-1) supplying the first raw material gas to the substrate; and (a-2) supplying the first reactant gas to the substrate; thereby forming a first layer containing the first element; and a second process comprising: (b-1) supplying the second raw material gas to the substrate; and (b-2) after the supply of the second raw material gas in (b-1) has been performed for a first period, supplying the substrate with the third raw material gas containing the second element not present in the first layer. (b-3) After the supply of the third raw material gas mentioned in (b-2) has been carried out for a second period, the process of supplying the second reaction gas to the substrate is performed for a second time, thereby forming a second layer containing the first element and the second element; thereby performing a process of forming a film containing the first element and the second element on the substrate, wherein the first element and the second element are metallic or semi-metallic elements, and the first reaction gas and the second reaction gas are gases containing the third element, namely nitrogen or oxygen.

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