Film formation method, semiconductor device manufacturing method, film formation apparatus, and program

Abstract

This film-forming method has (a) a step for supplying a first film-forming agent to a substrate received in a processing container to form a first nitride film on the substrate, and (b) a step for supplying a second film-forming agent to the first nitride film adhered to the inside of the processing container to form a second nitride film on the surface of the first nitride film adhered to the inside of the processing container, wherein: when the first nitride film having tensile stress is formed in (a), the second nitride film having compressive stress is formed in (b); and when the first nitride film having compressive stress is formed in (a), the second nitride film having tensile stress is formed in (b).

Description

[Technical Field]

[0001] The present disclosure relates to a film forming method, a method for manufacturing a semiconductor device, a film forming apparatus, and a program. [Background technology]

[0002] BACKGROUND ART One step in the manufacturing process of a semiconductor device is to form a nitride film on the surface of a substrate accommodated in a processing chamber (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-093551 [Patent Document 2] Japanese Patent Application Laid-Open No. 2017-168786 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when a nitride film is formed on a substrate, the nitride film is also formed and adheres to the inside of the processing chamber, and the film may peel off due to stress of the nitride film adhered to the inside of the processing chamber.

[0005] An object of the present disclosure is to provide a technology that can reduce stress on a film attached to the inside of a processing chamber and prevent the film from peeling off. [Means for solving the problem]

[0006] According to one aspect of the present disclosure, (a) supplying a first film-forming agent to a substrate accommodated in a processing chamber to form a first nitride film on the substrate; (b) supplying a second film-forming agent to the first nitride film adhering to the inside of the processing vessel in (a), thereby forming a second nitride film on the surface of the first nitride film adhering to the inside of the processing vessel; When the first nitride film having a tensile stress is formed in (a), the second nitride film having a compressive stress is formed in (b); When the first nitride film having compressive stress is formed in (a), a technique is provided in which the second nitride film having tensile stress is formed in (b). [Effects of the Invention]

[0007] According to the present disclosure, it is possible to reduce stress on a film attached to the inside of a processing chamber and prevent the film from peeling off. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram of a vertical processing furnace of a film forming apparatus suitably used in one embodiment of the present disclosure, showing a processing furnace 202 portion in vertical cross section. [Figure 2] FIG. 2 is a schematic configuration diagram of a vertical processing furnace of a film forming apparatus suitably used in one embodiment of the present disclosure, and is a cross-sectional view of the processing furnace 202 portion taken along line AA in FIG. [Figure 3] FIG. 3 is a schematic configuration diagram of a controller 121 of a film forming apparatus suitably used in one embodiment of the present disclosure, and is a block diagram showing a control system of the controller 121. [Figure 4] FIG. 4 is a schematic configuration diagram of an electrode unit in a film forming apparatus suitably used in one embodiment of the present disclosure, and is a perspective view of the electrode unit. [Figure 5] FIG. 5 is a diagram illustrating an example of a processing sequence according to an embodiment of the present disclosure. [Figure 6] FIG. 6 is a diagram showing another example of a processing sequence according to an embodiment of the present disclosure. [Figure 7] FIG. 7 is a diagram showing another example of a processing sequence according to an embodiment of the present disclosure. [Figure 8] FIG. 2 is an enlarged cross-sectional view of a portion of the inner wall of the processing vessel to which a first nitride film is attached. [Figure 9] 1 is an enlarged cross-sectional view of a portion of the inner wall of a processing vessel to which a laminated film formed by alternately stacking first nitride films and second nitride films is attached. [Figure 10] FIG. 10 is a diagram showing the measurement results of the stress of a nitride film. DETAILED DESCRIPTION OF THE INVENTION

[0009] <First Aspect of the Present Disclosure> The first embodiment of the present disclosure will be described below mainly with reference to Figures 1 to 9. Note that the drawings used in the following description are all schematic, and the dimensional relationships between elements, the ratios of elements, etc. shown in the drawings do not necessarily match those in reality. Furthermore, the dimensional relationships between elements, the ratios of elements, etc. do not necessarily match between multiple drawings.

[0010] (1) Configuration of the film deposition equipment As shown in Fig. 1, a processing furnace 202 of a film forming apparatus serving as a substrate processing apparatus has a heater 207 as a temperature regulator (heating unit). The heater 207 is cylindrical and is installed vertically by being supported by a holding plate. The heater 207 also functions as an activation mechanism (thermal excitation unit) that thermally activates (excites) gas.

[0011] A reaction tube 203 is disposed concentrically with the heater 207 inside the heater 207. The reaction tube 203 is made of a heat-resistant material such as quartz (SiO2) or silicon carbide (SiC) and has a cylindrical shape with a closed upper end and an open lower end. A manifold 209 is disposed concentrically with the reaction tube 203 below the reaction tube 203. The manifold 209 is made of a metal material such as stainless steel (SUS) and has a cylindrical shape with open upper and lower ends. The upper end of the manifold 209 engages with the lower end of the reaction tube 203 and is configured to support the reaction tube 203. An O-ring 220a is provided between the manifold 209 and the reaction tube 203 as a sealing member. The reaction tube 203 is installed vertically, similar to the heater 207. The reaction tube 203 and the manifold 209 mainly constitute a processing vessel (reaction vessel). A processing chamber 201 is formed in the cylindrical hollow portion of the processing vessel. The processing chamber 201 is configured to be able to accommodate a wafer 200 as a substrate. Processing of the wafer 200 is performed in this processing chamber 201, i.e., in this processing vessel.

[0012] Nozzles 249a to 249c serving as first to third supply units are respectively provided in the processing chamber 201 so as to penetrate the sidewall of the manifold 209. The nozzles 249a to 249c are also referred to as first to third nozzles, respectively. The nozzles 249a to 249c are made of a heat-resistant material such as quartz or SiC. Gas supply pipes 232a to 232c are connected to the nozzles 249a to 249c, respectively. The nozzles 249a to 249c are different nozzles, and each of the nozzles 249a and 249c is provided adjacent to the nozzle 249b.

[0013] Gas supply pipes 232a-232c are respectively provided with mass flow controllers (MFCs) 241a-241c, which are flow rate control devices (flow rate control parts), and valves 243a-243c, which are on-off valves, in order from the upstream side of the gas flow. Gas supply pipes 232d-232f are connected to gas supply pipes 232a-232c downstream of valves 243a-243c. Gas supply pipes 232d-232f are respectively provided with MFCs 241d-241f and valves 243d-243f in order from the upstream side of the gas flow. Gas supply pipes 232a-232f are made of a metal material, for example, SUS or the like.

[0014] 1 and 2, the nozzles 249a to 249c are respectively provided in an annular space between the inner wall of the reaction tube 203 and the wafers 200 in a plan view, extending from the lower part to the upper part of the inner wall of the reaction tube 203 and rising upward in the arrangement direction of the wafers 200. That is, the nozzles 249a to 249c are respectively provided in regions horizontally surrounding the wafer arrangement region on the sides of the wafer arrangement region where the wafers 200 are arranged, and extending along the wafer arrangement region. In a plan view, the nozzle 249b is disposed so as to face an exhaust port 231a (described later) on a straight line across the center of the wafer 200 loaded into the processing chamber 201. The nozzles 249a and 249c are disposed so as to sandwich a line L passing through the nozzle 249b and the center of the exhaust port 231a along the inner wall of the reaction tube 203 (the outer periphery of the wafers 200) from both sides. The line L is also a line passing through the nozzle 249b and the center of the wafer 200. In other words, the nozzle 249c can be said to be provided on the opposite side of the line L from the nozzle 249a. The nozzles 249a and 249c are arranged symmetrically, that is, symmetrically, with the line L as the axis of symmetry. Gas supply holes 250a to 250c for supplying gas are provided on the side surfaces of the nozzles 249a to 249c, respectively. Each of the gas supply holes 250a to 250c opens to face (face) the exhaust port 231a in a plan view, and is capable of supplying gas toward the wafer 200. A plurality of the gas supply holes 250a to 250c are provided from the bottom to the top of the reaction tube 203.

[0015] From the gas supply pipe 232a, raw materials (source gases) as film forming agents (first film forming agent, second film forming agent) are supplied into the processing chamber 201 via the MFC 241a, the valve 243a, and the nozzle 249a.

[0016] From the gas supply pipe 232b, a nitriding agent (nitriding gas, nitrogen source) as a film forming agent (first film forming agent, second film forming agent) is supplied into the processing chamber 201 via the MFC 241b, the valve 243b, and the nozzle 249b.

[0017] From the gas supply pipe 232c, an oxidizing agent (oxidizing gas, oxygen source) as a film forming agent (first film forming agent, second film forming agent) is supplied into the processing chamber 201 via the MFC 241c, the valve 243c, and the nozzle 249c.

[0018] Inert gas is supplied from the gas supply pipes 232d to 232f into the processing chamber 201 via the MFCs 241d to 241f, the valves 243d to 243f, the gas supply pipes 232a to 232c, and the nozzles 249a to 249c, respectively. The inert gas acts as a purge gas, a carrier gas, a dilution gas, etc. As will be described later, the inert gas can also be plasma-excited in the processing chamber 201 and then supplied. In this case, the inert gas can also act as a modifying gas, i.e., a film-forming agent (first film-forming agent, second film-forming agent).

[0019] A raw material supply system (raw material gas supply system) is mainly constituted by the gas supply pipe 232a, the MFC 241a, and the valve 243a. A nitriding agent supply system (nitriding source supply system, nitriding gas supply system) is mainly constituted by the gas supply pipe 232b, the MFC 241b, and the valve 243b. An oxidizing agent supply system (oxidizing source supply system, oxidizing gas supply system) is mainly constituted by the gas supply pipe 232c, the MFC 241c, and the valve 243c. An inert gas supply system is mainly constituted by the gas supply pipes 232d to 232f, the MFCs 241d to 241f, and the valves 243d to 243f. At least one of the raw material supply system, the nitriding agent supply system, the oxidizing agent supply system, and the inert gas supply system may also be referred to as a film forming agent supply system (first film forming agent supply system, second film forming agent supply system).

[0020] Any or all of the various supply systems described above may be configured as an integrated supply system 248 in which valves 243a-243f, MFCs 241a-241f, etc. are integrated. The integrated supply system 248 is connected to each of the gas supply pipes 232a-232f, and is configured so that the supply operation of various substances (various gases) into the gas supply pipes 232a-232f, i.e., the opening and closing operation of the valves 243a-243f and the flow rate adjustment operation by the MFCs 241a-241f, etc., are controlled by a controller 121, which will be described later. The integrated supply system 248 is configured as an integrated or separate integrated unit, and can be attached and detached to and from the gas supply pipes 232a-232f, etc., so that maintenance, replacement, expansion, etc. of the integrated supply system 248 can be performed on an integrated unit basis.

[0021] An exhaust port 231a for exhausting the atmosphere inside the processing chamber 201 is provided at the bottom of the sidewall of the reaction tube 203. As shown in FIG. 2, the exhaust port 231a is provided at a position facing (opposite) the nozzles 249a-249c (gas supply holes 250a-250c) across the wafer 200 in a plan view. The exhaust port 231a may be provided along the sidewall of the reaction tube 203 from the bottom to the top, i.e., along the wafer arrangement area. An exhaust pipe 231 is connected to the exhaust port 231a. The exhaust pipe 231 is made of a metal material such as SUS. A vacuum pump 246 serving as a vacuum exhaust device is connected to the exhaust pipe 231 via a pressure sensor 245 serving as a pressure detector (pressure detection unit) for detecting the pressure inside the processing chamber 201 and an APC (Auto Pressure Controller) valve 244 serving as a pressure regulator (pressure adjustment unit). The APC valve 244 is configured to be able to evacuate and stop the evacuation of the processing chamber 201 by opening and closing the valve while the vacuum pump 246 is operating, and further to be able to adjust the pressure inside the processing chamber 201 by adjusting the valve opening based on pressure information detected by the pressure sensor 245 while the vacuum pump 246 is operating. The APC valve 244 can also be called an exhaust valve. An exhaust system is mainly configured by the exhaust pipe 231, the APC valve 244, and the pressure sensor 245. The vacuum pump 246 may be included in the exhaust system.

[0022] A seal cap 219 serving as a furnace port cover capable of airtightly closing the lower end opening of the manifold 209 is provided below the manifold 209. The seal cap 219 is made of a metal material such as SUS and is formed in a disk shape. An O-ring 220b serving as a sealing member that abuts against the lower end of the manifold 209 is provided on the upper surface of the seal cap 219. A rotation mechanism 267 for rotating the boat 217 (described later) is provided below the seal cap 219. A rotation shaft 255 of the rotation mechanism 267 is made of a metal material such as SUS and is connected to the boat 217 through the seal cap 219. The rotation mechanism 267 is configured to rotate the boat 217, thereby rotating the wafers 200. The seal cap 219 is configured to be vertically raised and lowered by a boat elevator 115 serving as a lifting mechanism installed outside the reaction tube 203. The boat elevator 115 is configured as a transfer device (transfer mechanism) that transfers the wafers 200 into and out of the processing chamber 201 by raising and lowering the seal cap 219.

[0023] A shutter 219s is provided below the manifold 209 as a furnace port cover that can airtightly close the lower end opening of the manifold 209 when the seal cap 219 is lowered and the boat 217 is removed from the processing chamber 201. The shutter 219s is made of a metal material such as SUS and has a disk shape. An O-ring 220c is provided on the upper surface of the shutter 219s as a sealing member that abuts against the lower end of the manifold 209. The opening and closing operation (lifting and lowering operation, rotating operation, etc.) of the shutter 219s is controlled by a shutter opening and closing mechanism 115s.

[0024] The boat 217, which serves as a support for supporting substrates, is configured to support a plurality of wafers 200, for example, 25 to 200, in multiple stages, horizontally and aligned vertically with their centers aligned. That is, the boat 217 is configured to arrange the plurality of wafers 200 in a horizontal position and spaced apart vertically. The boat 217 is made of a heat-resistant material such as quartz or SiC. At the bottom of the boat 217, heat insulating plates 218, also made of a heat-resistant material such as quartz or SiC, are supported in multiple stages. The boat 217 is configured to be able to support each of the plurality of wafers 200.

[0025] A temperature sensor 263 serving as a temperature detector is installed inside the reaction tube 203. By adjusting the power supply to the heater 207 based on the temperature information detected by the temperature sensor 263, the temperature inside the processing chamber 201 can be adjusted to a desired temperature distribution. The temperature sensor 263 is installed along the inner wall of the reaction tube 203.

[0026] An electrode 300 for generating plasma is provided outside the reaction tube 203, i.e., outside the processing vessel (processing chamber 201). By applying power to the electrode 300, it is possible to convert gas into plasma and excite it inside the reaction tube 203, i.e., inside the processing vessel (processing chamber 201), i.e., to excite the gas into a plasma state. Hereinafter, exciting the gas into a plasma state will also be simply referred to as plasma excitation. The electrode 300 is configured to generate capacitively coupled plasma (CCP) inside the reaction tube 203, i.e., inside the processing vessel (processing chamber 201), by applying power, i.e., high-frequency power (RF power).

[0027] 2, an electrode 300 and an electrode fixture 301 for fixing the electrode 300 are disposed between the heater 207 and the reaction tube 203. The electrode fixture 301 is disposed inside the heater 207, the electrode 300 is disposed inside the electrode fixture 301, and the reaction tube 203 is disposed inside the electrode 300.

[0028] 1 and 2, the electrode 300 and the electrode fixture 301 are provided in a circular space between the inner wall of the heater 207 and the outer wall of the reaction tube 203 in a plan view, extending from the lower part to the upper part of the outer wall of the reaction tube 203 in the arrangement direction of the wafers 200. The electrode 300 is provided parallel to the nozzles 249a to 249c. The electrode 300 and the electrode fixture 301 are arranged and disposed in a concentric arc shape with the reaction tube 203 and the heater 207 in a plan view, but are not in contact with the reaction tube 203 or the heater 207. The electrode fixture 301 is made of an insulating material (insulator) and is provided to cover at least a part of the electrode 300 and the reaction tube 203. Therefore, the electrode fixture 301 can also be referred to as a cover (insulating cover, insulating wall, insulating plate) or a cross-sectional arc cover (cross-sectional arc body, cross-sectional arc wall).

[0029] As shown in Fig. 2, a plurality of electrodes 300 are provided, and these plurality of electrodes 300 are fixed and installed on the inner wall of an electrode fixture 301. More specifically, as shown in Fig. 4, the inner wall surface of the electrode fixture 301 is provided with protrusions (hooks) 301a onto which the electrodes 300 can be hooked, and the electrodes 300 are provided with openings 300c that are through-holes into which the protrusions 301a can be inserted. The electrodes 300 can be fixed to the electrode fixture 301 by hooking the electrodes 300 onto the protrusions 301a provided on the inner wall surface of the electrode fixture 301 through the openings 300c. Note that Fig. 4 shows an example in which two openings 300c are provided in one electrode 300, and one electrode 300 is fixed by hooking it onto the two protrusions 301a, i.e., an example in which one electrode 300 is fixed at two locations. 2 shows an example in which nine electrodes 300 are fixed to one electrode fixture 301, and FIG. 4 shows an example in which twelve electrodes 300 are fixed to one electrode fixture 301.

[0030] The electrode 300 is made of an oxidation-resistant material such as nickel (Ni). The electrode 300 can also be made of a metal material such as SUS, aluminum (Al), or copper (Cu). However, using an oxidation-resistant material such as Ni can suppress deterioration of electrical conductivity and reduce the decrease in plasma generation efficiency. Furthermore, the electrode 300 can also be made of an Al-added Ni alloy material. In this case, an aluminum oxide film (AlO film), which is an oxide film with high heat resistance and corrosion resistance, can be formed on the outermost surface of the electrode 300. The AlO film formed on the outermost surface of the electrode 300 acts as a protective film (block film, barrier film) and can suppress the progression of internal deterioration of the electrode 300. This can further suppress the decrease in plasma generation efficiency due to a decrease in the electrical conductivity of the electrode 300. The electrode fixture 301 is made of an insulating material (insulator), for example, a heat-resistant material such as quartz or SiC. The material of the electrode fixture 301 is preferably the same as that of the reaction tube 203.

[0031] As shown in FIG. 2, the electrode 300 includes a first electrode 300a and a second electrode 300b. The first electrode 300a is connected to a high-frequency power supply (RF power supply) 320 via a matching box 305. The second electrode 300b is grounded to earth and serves as a reference potential (0 V). The first electrode 300a is also referred to as a hot electrode or a hot electrode, and the second electrode 300b is also referred to as a ground electrode or a ground electrode. The first electrode 300a and the second electrode 300b are each configured as a plate-like member having a rectangular shape when viewed from the front. At least one first electrode 300a is provided, and at least one second electrode 300b is provided. FIGS. 1, 2, and 4 show an example in which a plurality of first electrodes 300a and a plurality of second electrodes 300b are provided. 2 shows an example in which six first electrodes 300a and three second electrodes 300b are provided on one electrode fixture 301, while FIG. 4 shows an example in which eight first electrodes 300a and four second electrodes 300b are provided on one electrode fixture 301. By applying RF power between the first electrode 300a and the second electrode 300b from the RF power supply 320 via the matching box 305, plasma is generated in the region between the first electrode 300a and the second electrode 300b. This region is also referred to as the plasma generation region.

[0032] The surface area of ​​the first electrode 300a is preferably two to three times the surface area of ​​the second electrode 300b. If the surface area of ​​the first electrode 300a is less than twice the surface area of ​​the second electrode 300b, the potential distribution may narrow, resulting in a decrease in plasma generation efficiency. If the surface area of ​​the first electrode 300a is more than three times the surface area of ​​the second electrode 300b, the potential distribution may extend to the edge of the wafer 200, causing the wafer 200 to become an obstacle and resulting in a saturation of plasma generation efficiency. In this case, discharge may also occur at the edge of the wafer 200, potentially causing plasma damage to the wafer 200. By setting the surface area of ​​the first electrode 300a to be two to three times the surface area of ​​the second electrode 300b, it is possible to increase plasma generation efficiency and suppress plasma damage to the wafer 200. 2, the electrodes 300 (first electrode 300a, second electrode 300b) are arranged in an arc shape in a plan view and are arranged at equal intervals, i.e., so that the distances (gaps) between adjacent electrodes 300 (first electrode 300a, second electrode 300b) are equal. As described above, the electrodes 300 (first electrode 300a, second electrode 300b) are arranged parallel to the nozzles 249a to 249c.

[0033] Here, the electrode fixture 301 and the electrode 300 (first electrode 300a, second electrode 300b) can also be referred to as an electrode unit. As shown in FIG. 2, the electrode unit is preferably arranged at a position avoiding the nozzles 249a to 249c, the temperature sensor 263, the exhaust port 231a, and the exhaust pipe 231. FIG. 2 shows an example in which two electrode units are arranged to face each other across the center of the wafer 200 (reaction tube 203), avoiding the nozzles 249a to 249c, the temperature sensor 263, the exhaust port 231a, and the exhaust pipe 231. Note that FIG. 2 shows an example in which the two electrode units are arranged line-symmetrically, i.e., symmetrically, with respect to a line L as an axis of symmetry in a plan view. By arranging the electrode units in this manner, it is possible to arrange the nozzles 249a to 249c, the temperature sensor 263, the exhaust port 231a, and the exhaust pipe 231 outside the plasma generation region within the processing chamber 201, thereby making it possible to suppress plasma damage to these components, wear and tear on these components, breakage of these components, and generation of particles from these components.

[0034] An excitation unit (plasma excitation unit, plasma activation mechanism) that excites (activates) gas into plasma is mainly configured by electrodes 300, i.e., first electrode 300a and second electrode 300b. The plasma excitation unit may also include electrode fixture 301, matching box 305, and RF power supply 320.

[0035] 3, the controller 121, which is a control unit (control means), is configured as a computer including a CPU (Central Processing Unit) 121a, a RAM (Random Access Memory) 121b, a storage device 121c, and an I / O port 121d. The RAM 121b, the storage device 121c, and the I / O port 121d are configured to be able to exchange data with the CPU 121a via an internal bus 121e. An input / output device 122 configured as, for example, a touch panel is connected to the controller 121. An external storage device 123 can also be connected to the controller 121.

[0036] The storage device 121c is configured with, for example, a flash memory, an HDD (Hard Disk Drive), an SSD (Solid State Drive), etc. The storage device 121c readably stores a control program for controlling the operation of the film forming apparatus, a process recipe describing the procedures and conditions of the processes described below, etc. The process recipe is a combination of procedures in the processes described below that are executed by the controller 121 in the film forming apparatus to obtain a predetermined result, and functions as a program. Hereinafter, the process recipe, the control program, etc. are collectively referred to simply as a program. The process recipe is also simply referred to as a recipe. In this specification, the term "program" may refer to a recipe alone, a control program alone, or both. The RAM 121b is configured as a memory area (work area) for temporarily storing programs, data, etc. read by the CPU 121a.

[0037] The I / O port 121d is connected to the above-mentioned MFCs 241a to 241f, valves 243a to 243f, pressure sensor 245, APC valve 244, vacuum pump 246, temperature sensor 263, heater 207, rotation mechanism 267, boat elevator 115, shutter opening / closing mechanism 115s, RF power supply 320, matching box 305, etc.

[0038] The CPU 121a is configured to read and execute a control program from the storage device 121c, and to read a recipe from the storage device 121c in response to an input of an operation command from the input / output device 122. The CPU 121a is configured to control, in accordance with the contents of the read recipe, the flow rate adjustment operation of various gases by the MFCs 241a to 241f, the opening and closing operations of the valves 243a to 243f, the opening and closing operation of the APC valve 244 and the pressure adjustment operation by the APC valve 244 based on the pressure sensor 245, the start and stop of the vacuum pump 246, the temperature adjustment operation of the heater 207 based on the temperature sensor 263, the rotation and rotation speed adjustment operation of the boat 217 by the rotation mechanism 267, the lifting and lowering operation of the boat 217 by the boat elevator 115, the opening and closing operation of the shutter 219s by the shutter opening and closing mechanism 115s, the impedance adjustment operation by the matching box 305, the power supply to the RF power source 320, and the like.

[0039] The controller 121 can be configured by installing the above-mentioned program stored in the external storage device 123 into a computer. The external storage device 123 includes, for example, a magnetic disk such as an HDD, an optical disk such as a CD, a magneto-optical disk such as an MO, and a semiconductor memory such as a USB memory or an SSD. The storage device 121c and the external storage device 123 are configured as computer-readable recording media. Hereinafter, these will be collectively referred to as recording media. When the term recording media is used in this specification, it may include only the storage device 121c alone, only the external storage device 123 alone, or both. Note that the program may be provided to the computer using a communication means such as the Internet or a dedicated line, without using the external storage device 123.

[0040] (2) Film formation process An example of a process sequence, i.e., a film formation sequence, will be described below, in which, as one step in a semiconductor device manufacturing process, a first nitride film is formed on wafer 200 as a substrate housed in a processing chamber, and a second nitride film is formed on the surface of the first nitride film attached to the inside of the processing chamber using the above-described film formation apparatus. In the following description, the operation of each part of the film formation apparatus is controlled by controller 121.

[0041] In the film formation sequence of this embodiment, a process (first film formation process) of forming a first nitride film on the wafer 200 by supplying a first film formation agent to the wafer 200 accommodated in a process chamber; a process (second film formation process) in which a second film forming agent is supplied to the first nitride film adhered to the inside of the processing vessel in the first film formation process, thereby forming a second nitride film on the surface of the first nitride film adhered to the inside of the processing vessel; When a first nitride film having tensile stress is formed in a first film formation process, a second nitride film having compressive stress is formed in a second film formation process.

[0042] In this embodiment, for example, a raw material and a nitriding agent are supplied as the first film-forming agent in the first film-forming process, and a first nitride film having tensile stress can be formed on the wafer 200. In this case, for example, a raw material, a nitriding agent, and an inert gas excited to a plasma state can be supplied as the second film-forming agent in the second film-forming process, and a second nitride film having compressive stress can be formed on the surface of the first nitride film attached to the inside of the processing chamber.

[0043] In this embodiment, for example, the nitriding agent can be excited into a plasma state and supplied in each of the first film formation process and the second film formation process.

[0044] In the first film formation process in this embodiment, as shown in the process sequence of FIG. Step A1 of supplying raw material to wafer 200 in a processing chamber; Step A2: supplying a nitriding agent excited into a plasma state to the wafer 200 in the processing chamber; The above-mentioned non-simultaneous cycle is repeated a predetermined number of times (n1 times, where n1 is an integer of 1 or more), thereby forming a first nitride film having tensile stress on the wafer 200.

[0045] In the second film formation process in this embodiment, as shown in the process sequence of FIG. Step B1 of supplying a source material to the first nitride film deposited in the processing chamber; a step B2 of supplying a nitriding agent excited into a plasma state to the first nitride film deposited inside the processing chamber; a step B3 of supplying an inert gas excited into a plasma state to the first nitride film deposited inside the processing chamber; The above-mentioned non-simultaneous cycle is repeated a predetermined number of times (n2 times, where n2 is an integer equal to or greater than 1), thereby forming a second nitride film having compressive stress on the surface of the first nitride film adhering to the inside of the processing chamber.

[0046] In this specification, the above-described processing sequence (gas supply sequence) may be expressed as follows for convenience: Similar notations will be used in the following descriptions of other aspects, modifications, etc.

[0047] First film formation process: (raw material → plasma-excited nitriding agent) × n1 Second film formation process: (raw material → plasma-excited nitriding agent → plasma-excited inert gas) × n2

[0048] The term "wafer" used in this specification may refer to the wafer itself or a laminate of the wafer and a predetermined layer or film formed on its surface. The term "surface of a wafer" used in this specification may refer to the surface of the wafer itself or the surface of a predetermined layer or the like formed on the wafer. When described in this specification, "forming a predetermined layer on a wafer" may mean forming a predetermined layer directly on the surface of the wafer itself or forming a predetermined layer on a layer or the like formed on the wafer. When used in this specification, the term "substrate" is synonymous with the term "wafer".

[0049] (2-1) First film formation process First, an example of the sequence of the first film formation process for forming a first nitride film having tensile stress on the wafer 200 will be described.

[0050] (Wafer charge) A plurality of wafers 200 are loaded (wafer charge) into the boat 217. After that, the shutter 219s is moved by the shutter opening / closing mechanism 115s to open the lower end opening of the manifold 209 (shutter open). The wafers 200 include product wafers and dummy wafers.

[0051] (boat load) 1, the boat 217 supporting the plurality of wafers 200 is lifted by the boat elevator 115 and loaded (boat loaded) into the processing chamber 201. In this state, the seal cap 219 seals the lower end of the manifold 209 via the O-ring 220b.

[0052] (pressure and temperature regulation) After the boat loading is completed, the processing chamber 201, i.e., the space in which the wafers 200 are present, is evacuated (reduced pressure exhausted) by the vacuum pump 246 so that the interior of the processing chamber 201 is at a desired pressure (vacuum level). At this time, the pressure inside the processing chamber 201 is measured by the pressure sensor 245, and the APC valve 244 is feedback-controlled based on the measured pressure information (pressure adjustment). Furthermore, the wafers 200 inside the processing chamber 201 are heated by the heater 207 so that the temperature is maintained at a desired processing temperature. At this time, the power supply to the heater 207 is feedback-controlled based on temperature information detected by the temperature sensor 263 so that the interior of the processing chamber 201 has a desired temperature distribution (temperature adjustment). Furthermore, the rotation mechanism 267 starts rotating the wafers 200. The evacuation inside the processing chamber 201 and the heating and rotation of the wafers 200 are all continued at least until the processing of the wafers 200 is completed.

[0053] (film formation process) Thereafter, the following steps A1 and A2 are executed in sequence.

[0054] [Step A1] In step A1, a raw material (raw material gas) is supplied to the wafer 200 in the processing chamber 201.

[0055] Specifically, the valve 243a is opened to allow the raw material to flow into the gas supply pipe 232a. The raw material has a flow rate adjusted by the MFC 241a, is supplied into the processing chamber 201 through the nozzle 249a, and is exhausted from the exhaust port 231a. At this time, the raw material is supplied to the wafer 200 from the side of the wafer 200 (raw material supply). At this time, the valves 243d to 243f may be opened to supply an inert gas into the processing chamber 201 through the nozzles 249a to 249c, respectively.

[0056] The processing conditions in this step are as follows: Treatment temperature: 250 to 550°C, preferably 400 to 500°C Treatment pressure: 100 to 4000 Pa, preferably 100 to 1000 Pa Raw material gas supply flow rate: 0.1 to 3 slm Raw material gas supply time: 1 to 100 seconds, preferably 1 to 30 seconds Inert gas supply flow rate (per gas supply pipe): 0 to 10 slm is exemplified.

[0057] In this specification, when a numerical range such as "250 to 550°C" is expressed, it means that the lower limit and the upper limit are included in the range. Therefore, for example, "250 to 550°C" means "250°C or higher and 550°C or lower." The same applies to other numerical ranges. In this specification, the processing temperature means the temperature of the wafer 200 or the temperature inside the processing chamber 201, and the processing pressure means the pressure inside the processing chamber 201. A gas supply flow rate of 0 slm means that the gas is not supplied. These also apply to the following explanations.

[0058] By supplying, for example, a chlorosilane-based gas as a raw material to the wafer 200 under the above-described processing conditions, a Si-containing layer containing Cl is formed on the top surface of the wafer 200 as a base. The Si-containing layer containing Cl is formed on the top surface of the wafer 200 by physical adsorption or chemical adsorption of chlorosilane-based gas molecules, physical adsorption or chemical adsorption of molecules of a substance formed by partial decomposition of the chlorosilane-based gas, or deposition of Si due to thermal decomposition of the chlorosilane-based gas. The Si-containing layer containing Cl may be an adsorption layer (physical adsorption layer or chemical adsorption layer) of chlorosilane-based gas molecules or molecules of a substance formed by partial decomposition of the chlorosilane-based gas, or may be a deposition layer of Si containing Cl. In this specification, the Si-containing layer containing Cl will also be simply referred to as a Si-containing layer. Under the above-described processing conditions, physisorption or chemisorption of chlorosilane-based gas molecules or molecules of substances formed by decomposition of the chlorosilane-based gas onto the outermost surface of the wafer 200 occurs predominantly (preferentially), and little or no Si is deposited due to thermal decomposition of the chlorosilane-based gas. That is, under the above-described processing conditions, the Si-containing layer contains an overwhelming number of adsorption layers (physisorption layers or chemisorption layers) of chlorosilane-based gas molecules or molecules of substances formed by decomposition of the chlorosilane-based gas, and contains little or almost no deposition layer of Si containing Cl.

[0059] After the Si-containing layer is formed, the valve 243a is closed to stop the supply of raw materials into the processing chamber 201. Then, the processing chamber 201 is evacuated to remove (purge) any gas remaining in the processing chamber 201. At this time, the valves 243d to 243f are opened to supply an inert gas into the processing chamber 201. The inert gas acts as a purge gas. The processing chamber 201 is purged in a non-plasma atmosphere. This makes it possible to prevent the raw materials remaining in the processing chamber 201 from mixing with the nitriding agent supplied into the processing chamber 201 in step A2, and to prevent unintended reactions (for example, gas-phase reactions or plasma-gas-phase reactions) and particle generation due to this.

[0060] The processing conditions for purging are as follows: Treatment temperature: 250 to 550°C, preferably 400 to 500°C Processing pressure: 1 to 20 Pa Inert gas supply flow rate (per gas supply pipe): 0.05 to 20 slm Inert gas supply time: 1 to 200 seconds, preferably 1 to 40 seconds is exemplified.

[0061] As a raw material, for example, a silane-based gas containing silicon (Si) as the main element constituting the film formed on the wafer 200 can be used. As the silane-based gas, for example, a gas containing halogen and Si, i.e., a halosilane-based gas can be used. Halogen includes chlorine (Cl), fluorine (F), bromine (Br), iodine (I), etc. As the halosilane-based gas, for example, the above-mentioned chlorosilane-based gas containing Cl and Si can be used.

[0062] Examples of usable raw materials include chlorosilane gases such as monochlorosilane (SiH3Cl, abbreviated as MCS) gas, dichlorosilane (SiH2Cl2, abbreviated as DCS) gas, trichlorosilane (SiHCl3, abbreviated as TCS) gas, tetrachlorosilane (SiCl4, abbreviated as 4CS) gas, hexachlorodisilane gas (Si2Cl6, abbreviated as HCDS) gas, and octachlorotrisilane (Si3Cl8, abbreviated as OCTS) gas. One or more of these can be used as raw materials.

[0063] As the raw material, in addition to chlorosilane-based gases, for example, fluorosilane-based gases such as tetrafluorosilane (SiF4) gas and difluorosilane (SiH2F2) gas, bromosilane-based gases such as tetrabromosilane (SiBr4) gas and dibromosilane (SiH2Br2) gas, and iodosilane-based gases such as tetraiodosilane (SiI4) gas and diiodosilane (SiH2I2) gas can be used. One or more of these can be used as the raw material.

[0064] In addition to these, a gas containing an amino group and Si, i.e., an aminosilane-based gas, can also be used as a raw material. An amino group is a monovalent functional group formed by removing hydrogen (H) from ammonia, a primary amine, or a secondary amine, and can be represented as -NH2, -NHR, or -NR2. R represents an alkyl group, and the two Rs in -NR2 may be the same or different.

[0065] As the raw material, for example, aminosilane gases such as tetrakis(dimethylamino)silane (Si[N(CH3)2]4, abbreviated as 4DMAS) gas, tris(dimethylamino)silane (Si[N(CH3)2]3H, abbreviated as 3DMAS) gas, bis(diethylamino)silane (Si[N(C2H5)2]2H2, abbreviated as BDEAS) gas, bis(tertiarybutylamino)silane (SiH2[NH(C4H9)]2, abbreviated as BTBAS) gas, and (diisopropylamino)silane (SiH3[N(C3H7)2], abbreviated as DIPAS) gas can be used. One or more of these can be used as the raw material.

[0066] Examples of inert gases that can be used include nitrogen (N2) gas and rare gases such as argon (Ar) gas, helium (He) gas, neon (Ne) gas, xenon (Xe) gas, krypton (Kr) gas, and radon (Rn) gas. One or more of these gases can be used as the inert gas. This also applies to the steps described below.

[0067] [Step A2] After step A1 is completed, a nitriding agent is plasma-excited and supplied to the wafer 200 in the processing chamber 201, that is, to the Si-containing layer formed on the wafer 200.

[0068] Specifically, the valve 243b is opened to allow the nitriding agent to flow into the gas supply pipe 232b. The flow rate of the nitriding agent is adjusted by the MFC 241b, and the nitriding agent is supplied into the processing chamber 201 through the nozzle 249b and exhausted from the exhaust port 231a. At this time, the nitriding agent is supplied to the wafer 200 from the side of the wafer 200 (nitriding agent supply). At this time, the valves 243d to 243f may be opened to supply an inert gas into the processing chamber 201 through the nozzles 249a to 249c, respectively.

[0069] At this time, RF power is applied between the first electrode 300a and the second electrode 300b to generate plasma in the region between the first electrode 300a and the second electrode 300b. This allows the nitriding agent to be plasma-excited, and activated species X generated by the plasma-excitation of the nitriding agent are supplied to the wafer 200 (plasma-excited nitriding agent supply). At this time, the nitriding agent containing activated species X is supplied to the wafer 200.

[0070] When a gas containing nitrogen (N) and hydrogen (H) is used as the nitriding agent, the N and H containing gas are excited into a plasma state to form NH x * (x is an integer of 1 to 3) and other activated species X are generated and supplied to the wafer 200 (plasma-excited N and H-containing gas supply). * , NH2 * , NH3 * An N- and H-containing gas containing activated species X such as the above is supplied. Note that * means a radical. The same applies to the following explanation.

[0071] Before supplying the nitriding agent to the wafer 200 after plasma excitation, a period of time during which the nitriding agent is supplied without plasma excitation may be provided. That is, before supplying the plasma-excited nitriding agent to the wafer 200, a non-plasma-excited nitriding agent may be supplied, i.e., a preflow of the non-plasma-excited nitriding agent may be performed (non-plasma-excited nitriding agent preflow). In this case, the nitriding agent is first supplied without plasma excitation, and after a predetermined period of time has elapsed, RF power is applied between the first electrode 300a and the second electrode 300b while the supply of the nitriding agent is continued. This allows for the generation of more stable plasma and activated species.

[0072] The processing conditions in this step are as follows: Treatment temperature: 250 to 550°C, preferably 400 to 500°C Treatment pressure: 2 to 100 Pa, preferably 20 to 70 Pa Nitriding agent supply flow rate: 0.1 to 10 slm Nitriding agent supply time: 10 to 200 seconds, preferably 1 to 50 seconds Inert gas supply flow rate (per gas supply pipe): 0 to 10 slm RF power: 100~1000W RF frequency: 13.56MHz or 27MHz is exemplified.

[0073] By supplying the nitriding agent to the wafer 200 in a plasma-excited state under the above-described processing conditions, at least a portion of the Si-containing layer formed on the wafer 200 is nitrided (modified). As a result, a silicon nitride layer (SiN layer) containing Si and N is formed on the top surface of the wafer 200 as a base. When the SiN layer is formed, impurities such as Cl contained in the Si-containing layer form a gaseous substance containing at least Cl during the process of the modification reaction of the Si-containing layer by the plasma-excited nitriding agent, and are exhausted from the processing chamber 201. As a result, the SiN layer contains fewer impurities such as Cl than the Si-containing layer formed in step A1.

[0074] After the SiN layer is formed, the valve 243b is closed to stop the supply of the nitriding agent into the processing chamber 201, and gases remaining in the processing chamber 201 are removed (purged) from the processing chamber 201 by the same processing procedure as in step A1.

[0075] As the nitriding agent, for example, a gas containing N and H can be used. The gas containing N and H is both an N-containing gas and an H-containing gas. The nitriding agent preferably has an N-H bond.

[0076] As the nitriding agent, for example, a hydrogen nitride gas such as ammonia (NH3) gas, diazene (N2H2) gas, hydrazine (N2H4) gas, N3H8 gas, etc. As the nitriding agent, one or more of these can be used.

[0077] In addition to these, a nitrogen (N), carbon (C), and hydrogen (H)-containing gas can also be used as the nitriding agent. An amine-based gas or an organic hydrazine-based gas can be used as the N, C, and H-containing gas. The N, C, and H-containing gas can be an N-containing gas, a C-containing gas, an H-containing gas, or an N- and C-containing gas.

[0078] Examples of nitriding agents that can be used include ethylamine-based gases such as monoethylamine (C2H5NH2, abbreviated as MEA) gas, diethylamine ((C2H5)2NH, abbreviated as DEA) gas, and triethylamine ((C2H5)3N, abbreviated as TEA) gas; methylamine-based gases such as monomethylamine (CH3NH2, abbreviated as MMA) gas, dimethylamine ((CH3)2NH, abbreviated as DMA) gas, and trimethylamine ((CH3)3N, abbreviated as TMA) gas; and organic hydrazine-based gases such as monomethylhydrazine ((CH3)HN2H2, abbreviated as MMH) gas, dimethylhydrazine ((CH3)2N2H2, abbreviated as DMH) gas, and trimethylhydrazine ((CH3)2N2(CH3)H, abbreviated as TMH) gas. One or more of these can be used as the nitriding agent.

[0079] [Perform the cycle a specified number of times] By performing the above-described steps A1 and A2 asynchronously, i.e., non-synchronized, a predetermined number of times (n1 times, where n1 is an integer greater than or equal to 1), a first nitride film, e.g., a silicon nitride film (SiN film) of a predetermined thickness, can be formed on the surface of the wafer 200 as a base. The above-described cycle is preferably repeated multiple times. That is, it is preferable to make the thickness of the SiN layer formed per cycle thinner than the desired film thickness, and to repeat the above-described cycle multiple times until the thickness of the SiN film formed by stacking the SiN layers reaches the desired thickness. When a gas containing N, C, and H is used as the nitriding agent, a silicon carbonitride layer (SiCN layer) can also be formed in step A2. By performing the above-described cycle a predetermined number of times, a nitride film, e.g., a silicon carbonitride film (SiCN film) can also be formed on the surface of the wafer 200.

[0080] The first nitride film formed by the above-mentioned processing procedure and processing conditions has a predetermined magnitude of tensile stress.

[0081] (After purging and atmospheric pressure recovery) After the process of forming a first nitride film of a desired thickness on the wafer 200 is completed, an inert gas is supplied as a purge gas from each of the nozzles 249a to 249c into the processing chamber 201 and exhausted from the exhaust port 231a. This purges the processing chamber 201, and gases and reaction by-products remaining in the processing chamber 201 are removed from the processing chamber 201 (after-purge). Thereafter, the atmosphere in the processing chamber 201 is replaced with the inert gas (inert gas replacement), and the pressure in the processing chamber 201 is returned to normal pressure (atmospheric pressure return).

[0082] (Boat unloading) Thereafter, the seal cap 219 is lowered by the boat elevator 115, and the lower end of the manifold 209 is opened. Then, the processed wafers 200, supported by the boat 217, are carried out from the lower end of the manifold 209 to the outside of the reaction tube 203 (boat unloading). After the boat unloading, the shutter 219s is moved, and the lower end opening of the manifold 209 is sealed by the shutter 219s via the O-ring 220c (shutter closing).

[0083] (wafer cooling) After the boat is unloaded, that is, after the shutter is closed, the processed wafers 200 are cooled down to a predetermined temperature at which they can be taken out while still supported by the boat 217 (wafer cooling).

[0084] (wafer discharge) After the wafers are cooled, the processed wafers 200 are cooled to a predetermined temperature at which they can be removed, and are then removed from the boat 217 (wafer discharging).

[0085] This completes the first film formation process for forming the first nitride film on the wafer 200. This process is performed a predetermined number of times (one or more times).

[0086] (2-2) Second film formation process When the first film formation process is performed, a first nitride film also adheres to the surfaces of components inside the process vessel, such as the inner wall surface of the reaction tube 203 and the surface of the boat 217. FIG. 8 shows a partially enlarged cross-sectional view of the inner wall of the process vessel to which the first nitride film adheres, i.e., the inner wall of the reaction tube 203, after the first film formation process has been repeatedly performed. The first nitride film has a predetermined stress (tensile stress in this embodiment). When the cumulative film thickness increases due to repeated first film formation processes, this stress can cause the film to crack and peel off from the surface of the component, resulting in the generation of foreign matter (particles) inside the furnace. Therefore, after the first film formation process is performed, a second nitride film having a predetermined stress (compressive stress in this embodiment) is formed on the surface of the first nitride film adhered to the inside of the process vessel at a predetermined timing, and a second film formation process is performed to relieve the film stress.

[0087] An example of a sequence of a second film formation process for forming a second nitride film having compressive stress on the surface of a first nitride film attached inside a processing chamber will be described below. In the following description, the operation of each part constituting the substrate processing apparatus is controlled by the controller 121.

[0088] (Empty boat load) The shutter 219s is moved by the shutter opening / closing mechanism 115s, and the lower end opening of the manifold 209 is opened (shutter open). Thereafter, the empty boat 217 with the first nitride film attached to its surface, i.e., the boat 217 not holding any wafers 200, is lifted by the boat elevator 115 and loaded (empty boat loaded) into the processing vessel with the first nitride film attached to its surface, i.e., the processing chamber 201. In this state, the seal cap 219 seals the lower end of the manifold 209 via the O-ring 220b.

[0089] (pressure and temperature regulation) After the empty boat loading is completed, the vacuum pump 246 evacuates (depressurizes) the processing chamber 201 to a desired pressure (vacuum level). At this time, the pressure in the processing chamber 201 is measured by the pressure sensor 245, and the APC valve 244 is feedback-controlled based on the measured pressure information (pressure adjustment). The processing chamber 201 is also heated by the heater 207 to a desired processing temperature. At this time, the power supply to the heater 207 is feedback-controlled based on temperature information detected by the temperature sensor 263 to achieve a desired temperature distribution in the processing chamber 201 (temperature adjustment). The rotation mechanism 254 also starts rotating the empty boat 217. The operation of the vacuum pump 246, the heating of the processing chamber 201, and the rotation of the boat 217 are all continued until the second film formation process is completed. The boat 217 does not necessarily have to be rotated.

[0090] (film formation process) Thereafter, the following steps B1, B2, and B3 are executed in sequence.

[0091] [Step B1] In step B1, raw materials are supplied to the first nitride film deposited inside the processing vessel using the same processing procedure and conditions as in step A1 (raw material supply). By performing this step, a Si-containing layer is formed on the surface of the first nitride film deposited inside the processing vessel.

[0092] After the Si-containing layer is formed, the supply of raw materials into the processing chamber 201 is stopped, and gases remaining in the processing chamber 201 are removed (purged) from the processing chamber 201 by the same processing procedure as the purging in step A1.

[0093] [Step B2] After step B1 is completed, a nitriding agent is plasma-excited and supplied to the Si-containing layer formed on the surface of the first nitride film attached to the inside of the processing vessel using the same processing procedure and processing conditions as those for the plasma-excited nitriding agent supply in step A2 (plasma-excited nitriding agent supply). By performing this step, a SiN layer is formed on the surface of the first nitride film attached to the inside of the processing vessel.

[0094] After the SiN layer is formed, the supply of the nitriding agent into the processing chamber 201 is stopped. Thereafter, step B3 is performed. However, before that, the processing chamber 201 may be purged in a non-plasma atmosphere. In this case, gases remaining in the processing chamber 201 can be removed from the processing chamber 201 (purging) by a processing procedure similar to the purging in step A1. This makes it possible to prevent the plasma-excited nitriding agent remaining in the processing chamber 201 from mixing with the plasma-excited inert gas supplied into the processing chamber 201 in step B3, which can result in unintended reactions (e.g., plasma gas-phase reactions), particle generation, etc.

[0095] [Step B3] After step B2 is completed, an inert gas is plasma-excited and supplied to the SiN layer formed on the surface of the first nitride film.

[0096] Specifically, valves 243d to 243f are opened to allow inert gas to flow into gas supply pipes 232d to 232f, respectively. The inert gas has its flow rate adjusted by MFCs 241d to 241f, is supplied into the processing chamber 201 via nozzles 249a to 249c, respectively, and is exhausted from the exhaust port 231a. At this time, the inert gas is supplied to the wafer 200 from the side of the wafer 200 (inert gas supply).

[0097] At this time, by applying RF power between the first electrode 300a and the second electrode 300b, plasma is generated in the region between the first electrode 300a and the second electrode 300b. This allows the inert gas to be plasma-excited, and the activated species Y generated by the plasma-excited inert gas are supplied to the SiN layer formed on the surface of the first nitride film (plasma-excited inert gas supply). At this time, the inert gas containing the activated species Y is supplied to the SiN layer formed on the surface of the first nitride film.

[0098] When N2 gas is used as the inert gas, for example, the N2 gas is plasma-excited to form N x * (x is an integer of 1 to 2) and other activated species Y are generated and supplied to the wafer 200 (plasma-excited N2 gas supply). * , N2 * N2 gas containing activated species Y such as

[0099] When Ar gas is used as the inert gas, the Ar gas is excited into plasma and becomes Ar * and the like are generated and supplied to the wafer 200 (plasma-excited Ar gas supply). * Ar gas containing activated species Y such as argon is supplied.

[0100] When He gas is used as the inert gas, for example, the He gas is excited into plasma and * and the like are generated and supplied to the wafer 200 (plasma-excited He gas supply).* He gas containing activated species Y such as

[0101] As the inert gas, these gases can be mixed and used as a mixed gas in the processing chamber 201. For example, as the inert gas, a mixed gas of N2 gas and Ar gas can be used, a mixed gas of N2 gas and He gas can be used, or a mixed gas of N2 gas, Ar gas, and He gas can be used.

[0102] Before supplying the inert gas to the SiN layer formed on the surface of the first nitride film after plasma excitation, a period of supplying the inert gas without plasma excitation may be provided. That is, before supplying the plasma-excited inert gas to the SiN layer formed on the surface of the first nitride film, a non-plasma-excited inert gas may be supplied, i.e., a non-plasma-excited inert gas preflow may be performed (non-plasma-excited inert gas preflow). In this case, the inert gas may be first supplied without plasma excitation, and after a predetermined period has elapsed, RF power may be applied between the first electrode 300a and the second electrode 300b while the inert gas supply is continued. This allows for the generation of more stable plasma and activated species.

[0103] The processing conditions in this step are as follows: Treatment temperature: 250 to 550°C, preferably 400 to 500°C Treatment pressure: 2 to 6 Pa, preferably 2.66 to 5.32 Pa, more preferably 3 to 4 Pa Inert gas supply flow rate (per gas supply pipe): 0.01 to 2 slm Inert gas supply time: 1 to 300 seconds, preferably 10 to 60 seconds RF power: 100~1000W RF frequency: 13.56MHz or 27MHz is exemplified.

[0104] By supplying a plasma-excited inert gas into the processing chamber under the above-described processing conditions, the SiN layer formed on the surface of the first nitride film is modified. During this process, impurities such as Cl remaining in the SiN layer are converted into gaseous substances containing at least Cl during the SiN layer modification reaction with the activated species Y, and the gaseous substances are exhausted from the processing chamber 201. As a result, the SiN layer modified in this step contains fewer impurities such as Cl than the SiN layer formed in step B2. Furthermore, due to this modification, the SiN layer modified in this step has a shorter interatomic distance between Si and N atoms than the SiN layer formed in step B2. As a result, the SiN layer is densified, and the SiN layer modified in this step has a higher density than the SiN layer formed in step B2.

[0105] Due to the modification reaction with the nitriding agent in step B2, the content of impurities such as Cl in the SiN layer formed in step B2 is reduced compared to the content of impurities such as Cl in the Si-containing layer formed in step B1. However, impurities such as Cl, for example, at a few atomic percent, may remain in the SiN layer formed in step B2 without being completely removed by the modification reaction with the nitriding agent. In this step, impurities such as Cl that remain in the SiN layer without being completely removed by the modification reaction with the nitriding agent can be removed by the activated species Y.

[0106] After the modification process of the SiN layer is completed, the application of RF power to the electrode 300 is stopped, and the supply of the plasma-excited inert gas into the processing chamber is stopped. When the above cycle is repeated multiple times, step B1 is performed again after step B3 is completed. However, before that, the processing chamber 201 may be purged in a non-plasma atmosphere. In this case, gases remaining in the processing chamber 201 can be removed from the processing chamber 201 by a processing procedure similar to the purging in step B1 (purging). This makes it possible to prevent the plasma-excited inert gas remaining in the processing chamber 201 from mixing with the raw material supplied into the processing chamber 201 in step B1, and thereby prevent unintended reactions (e.g., gas-phase reactions or plasma-gas-phase reactions) and particle generation.

[0107] As the inert gas, for example, N2 gas or a rare gas such as Ar gas, He gas, Ne gas, Xe gas, Kr gas, Rn gas, etc. One or more of these can be used as the inert gas.

[0108] [Perform the cycle a specified number of times] By performing the above-described steps B1, B2, and B3 asynchronously, i.e., by repeating the cycle a predetermined number of times (n2 times, where n2 is an integer greater than or equal to 1), a second nitride film, e.g., a SiN film, of a predetermined thickness, can be formed on the surface of the first nitride film deposited inside the processing chamber. The above-described cycle is preferably repeated multiple times. That is, it is preferable to make the thickness of the SiN layer formed per cycle thinner than the desired film thickness, and to repeat the above-described cycle multiple times until the thickness of the SiN film formed by stacking the SiN layers reaches the desired thickness. When a gas containing N, C, and H is used as the nitriding agent, a SiCN layer, for example, can also be formed in step B2. By performing the above-described cycle a predetermined number of times, a nitride film, e.g., a SiCN film, can also be formed on the surface of the wafer 200.

[0109] The second nitride film formed by the above-mentioned processing procedure and processing conditions has a predetermined magnitude of compressive stress.

[0110] (After purging and atmospheric pressure recovery) After the process of forming the second nitride film on the surface of the first nitride film is completed, an inert gas is supplied as a purge gas from each of the nozzles 249a to 249c into the processing chamber 201 and exhausted from the exhaust port 231a. This purges the processing chamber 201, and gases and reaction by-products remaining in the processing chamber 201 are removed from the processing chamber 201 (after-purge). Thereafter, the atmosphere in the processing chamber 201 is replaced with the inert gas (inert gas replacement), and the pressure in the processing chamber 201 is returned to normal pressure (atmospheric pressure return).

[0111] (Unloading empty boats) Thereafter, the seal cap 219 is lowered by the boat elevator 115, and the lower end of the manifold 209 is opened. Then, the empty boat 217 having the second nitride film formed on its surface is carried out from the lower end of the manifold 209 to the outside of the reaction tube 203 (empty boat unloading). After the empty boat unloading, the shutter 219s is moved, and the lower end opening of the manifold 209 is sealed by the shutter 219s via the O-ring 220c (shutter closing).

[0112] In this way, the second film formation process for forming a second nitride film on the surface of the first nitride film deposited inside the processing vessel is completed. This process may be performed each time the first film formation process is performed, or may be performed each time the first film formation process is performed multiple times. Figure 9 shows a partially enlarged cross-sectional view of the inner wall of the processing vessel, i.e., the inner wall of the reaction tube 203, to which a stacked film formed by alternately stacking first nitride films and second nitride films is deposited by alternately performing the first film formation process and the second film formation process.

[0113] (3) Effects of this mode According to this aspect, one or more of the following effects can be obtained.

[0114] (a) When a first nitride film having tensile stress is formed in the first film formation process, a second nitride film having compressive stress is formed in the second film formation process, thereby alleviating the stress of the film adhering to the inside of the processing chamber and increasing the cumulative film thickness at which film peeling occurs. This makes it possible to lengthen the cleaning cycle (maintenance cycle) and reduce the downtime of the film formation apparatus. As a result, it becomes possible to improve the productivity of the film formation process. Furthermore, since the film adhering to the inside of the processing chamber is less likely to peel off, it is possible to suppress the generation of particles, improving the quality of the film formed on the wafer 200 and significantly increasing the yield.

[0115] In addition, when a nitride film having tensile stress is formed in the first film formation process, a method of forming an oxide film having compressive stress in the second film formation process can be considered to relieve the stress of the film attached to the inside of the processing vessel.

[0116] However, when an oxide film is formed in the second film formation process, an oxidant supply system that is not required for the first film formation process must be prepared for the second film formation process. In contrast, according to the present embodiment, an oxidant is not used in either the first or second film formation process, and therefore an oxidant supply system is not required, thereby reducing the manufacturing cost of the film formation apparatus.

[0117] Furthermore, when an oxide film is formed in the second film formation process, it may be necessary to set the temperature conditions in the second film formation process different from those in the first film formation process. In this case, a long waiting time for temperature adjustment is required between the first and second film formation processes, which may increase the downtime of the film formation apparatus. Furthermore, there is a concern that a change in temperature inside the processing vessel may cause the film adhering to the processing vessel to crack due to thermal stress, resulting in the generation of particles. In contrast, according to this aspect, since a nitride film is formed in the second film formation process, it is not necessary to set the temperature conditions in the second film formation process different from those in the first film formation process, thereby avoiding such problems.

[0118] Furthermore, when an oxide film is formed in the second film formation process, an oxidizing agent or its components may remain in the processing vessel. In this case, in the subsequent first film formation process, the oxidizing agent or its components desorbed from the inner wall of the processing vessel may be mixed into the film formed on the wafer 200, deteriorating the film quality. In contrast, according to this embodiment, an oxidizing agent is not used in the second film formation process, and therefore, no oxidizing agent or its components remain in the processing vessel, making it possible to avoid such problems.

[0119] Furthermore, when an oxide film is formed in the second film formation process and nitride films having tensile stress and oxide films having compressive stress are alternately stacked in the processing vessel, there is a concern that film peeling occurs at the interface between the oxide film and the nitride film due to the difference in thermal expansion coefficients of these films, resulting in the generation of particles. In contrast, according to this embodiment, by using nitride films as all of the films alternately stacked in the processing vessel, the difference in thermal expansion coefficients of these films can be reduced, thereby making it possible to avoid such problems.

[0120] Furthermore, when an oxide film is formed in the second film formation process, the outermost surface of the inner wall surface of the processing vessel becomes an oxide film in the initial stage of the subsequent first film formation process, which may temporarily reduce the formation rate of the nitride film formed on the wafer 200 and cause a phenomenon in which the thickness of the nitride film formed on the wafer 200 temporarily drops (film thickness drop phenomenon). In contrast, according to this embodiment, since a nitride film is formed in the second film formation process, the outermost surface of the inner wall surface of the processing vessel can be maintained as a nitride film, making it possible to suppress the film thickness drop phenomenon.

[0121] (b) When a first nitride film having tensile stress is formed in the first film formation process, a second nitride film having compressive stress can be efficiently formed at low temperatures by supplying a raw material, a nitriding agent, and an inert gas excited to a plasma state as the second film formation agent in the second film formation process.

[0122] (c) In the second film formation process, by depositing a second nitride film on the surface of the first nitride film, it is possible to controllably relieve the stress of the film attached to the inside of the processing vessel, regardless of the thickness of the film attached to the inside of the processing vessel.

[0123] (d) In the first film formation process, a raw material and a nitriding agent are supplied as the first film formation agent, thereby making it possible to efficiently form a first nitride film having tensile stress.

[0124] (e) In the first film formation process and the second film formation process, the nitriding agent is excited into a plasma state and then supplied, thereby enabling the first nitride film and the second nitride film to be efficiently formed at low temperatures.

[0125] (f) When the second film formation process is performed every time the first film formation process is performed, it is possible to effectively relieve the stress of the film adhering to the inside of the processing container.

[0126] (g) When the second film formation process is performed each time the first film formation process is performed multiple times, the frequency with which the second film formation process is performed can be reduced, and the amount of the second film formation agent used can be reduced.

[0127] (h) By performing the second film formation process without placing the wafer 200 in the processing vessel, it is possible to relieve the stress of the film adhering to the inside of the processing vessel without adversely affecting the first nitride film formed on the wafer 200.

[0128] (i) By performing the first film formation process with the wafers 200 supported by the boat 217 in the processing vessel, and performing the second film formation process with an empty boat 217 that is not supporting the wafers 200 contained in the processing vessel, it is possible to relieve the stress of the film attached to the boat 217.

[0129] (j) In the second film formation process, by using at least one of N2 gas and a rare gas as the inert gas to be excited into a plasma state, it becomes possible to efficiently form a second nitride film having compressive stress.

[0130] (k) In the first film formation process and the second film formation process, by using a gas containing N and H as a nitriding agent, it becomes possible to efficiently form the first nitride film and the second nitride film, respectively.

[0131] (l) When any of the above-mentioned various raw material gases is used, when any of the above-mentioned various nitriding agents is used, or when any of the above-mentioned various inert gases is used, the above-mentioned various effects can be obtained.

[0132] (4) Variations The processing sequence in this embodiment can be modified as shown in the following modified examples. These modified examples can be combined as desired. Unless otherwise specified, the processing procedures and processing conditions in each step of each modified example can be the same as the processing procedures and processing conditions in each step of the above-described processing sequence.

[0133] (Variation 1) When a first nitride film having tensile stress is formed in the first film formation process, a raw material and an inert gas excited to a plasma state may be supplied as a second film formation agent in the second film formation process, and a second nitride film having compressive stress may be formed on the surface of the first nitride film.

[0134] Specifically, as shown in FIG. 7 and the processing sequence below, in the second film formation process of this modified example, a step C1 of supplying a source material to the first nitride film deposited in the processing chamber; a step C2 of supplying an inert gas excited into a plasma state to the first nitride film deposited inside the processing chamber; The above steps may be performed non-simultaneously a predetermined number of times (n3 times, where n3 is an integer of 1 or more), thereby forming a second nitride film having compressive stress on the surface of the first nitride film.

[0135] Second film formation process: (raw material → plasma-excited inert gas) × n3

[0136] In step C1, raw materials are supplied to the first nitride film deposited inside the processing chamber using the same processing procedure and processing conditions as in step A1 described above (raw material supply). The raw materials may be raw materials containing Si-N bonds, such as silylamine gases such as monosilylamine ((SiH3)NH2, abbreviated as MSA) gas, disilylamine ((SiH3)2NH, abbreviated as DSA) gas, and trisilylamine ((SiH3)3N, abbreviated as TSA) gas. One or more of these may be used as the raw material. Among these, TSA gas containing three Si-N bonds is preferably used as the raw material. These raw materials may be supplied to the wafer 200 from the raw material supply system described above. By performing this step, a SiN layer containing Si-N bonds is formed on the surface of the first nitride film deposited inside the processing chamber.

[0137] In step C2, an inert gas is plasma-excited and supplied to the SiN layer formed on the surface of the first nitride film deposited inside the processing chamber using the same processing procedure and conditions as the plasma-excited inert gas supply in step B3 described above (plasma-excited inert gas supply). As with the inert gas in step B3, the inert gas may be N2 gas or a rare gas such as Ar gas, He gas, Ne gas, or Xe gas. One or more of these may be used as the inert gas. In this modification, it is preferable to use N2 gas as the inert gas. These inert gases may be supplied to the wafer 200 from the inert gas supply system described above.

[0138] In the second film formation process of this modification, a second nitride film having compressive stress can be deposited on the surface of a first nitride film having tensile stress, and the same effects as those of the above-described embodiment can be obtained. Furthermore, according to this modification, the supply of a nitriding agent can be omitted in the second film formation process, thereby shortening the processing time. As a result, throughput, i.e., productivity, can be improved.

[0139] (Variation 2) When a first nitride film having tensile stress is formed in the first film formation process, step D may be performed in the second film formation process to supply an inert gas excited to a plasma state as a second film formation agent, thereby forming a second nitride film having compressive stress on the surface of the first nitride film.

[0140] In step D, an inert gas is plasma-excited and supplied to the first nitride film deposited inside the processing chamber using the same processing procedure and conditions as the plasma-excited inert gas supply in step B3 described above (plasma-excited inert gas supply). As with the inert gas in step B3, the inert gas may be N2 gas or a rare gas such as Ar gas, He gas, Ne gas, or Xe gas. One or more of these may be used as the inert gas. In this modification, it is preferable to use N2 gas as the inert gas. These inert gases may be supplied to the wafer 200 from the inert gas supply system described above.

[0141] In the second film formation process of this modification, the surface of a first nitride film having tensile stress can be modified to change the surface into a second nitride film having compressive stress. That is, in the second film formation process of this modification, a portion of the surface side of the first nitride film having tensile stress can be modified to change the portion of the surface side into a second nitride film having compressive stress. As a result, a stacked film is formed in the processing vessel, consisting of a first nitride film having tensile stress and a second nitride film having compressive stress, thereby achieving the same effect as the above-described embodiment. Furthermore, according to this modification, the surface of the first nitride film is modified to change the film into a second nitride film without depositing a second nitride film on the surface of the first nitride film. This allows for well-controlled reduction of stress in the film adhering to the processing vessel without increasing the thickness (cumulative film thickness) of the film adhering to the processing vessel. Furthermore, according to this modification, the supply of raw materials and nitriding agent can be omitted, thereby shortening the processing time. As a result, throughput, i.e., productivity, can be improved.

[0142] <Second Aspect of the Present Disclosure> In the film formation sequence of this embodiment, a process (first film formation process) of forming a first nitride film on the wafer 200 by supplying a first film formation agent to the wafer 200 accommodated in a process chamber; a process (second film formation process) in which a second film forming agent is supplied to the first nitride film adhered to the inside of the processing vessel in the first film formation process, thereby forming a second nitride film on the surface of the first nitride film adhered to the inside of the processing vessel; When a first nitride film having compressive stress is formed in a first film formation process, a second nitride film having tensile stress is formed in a second film formation process.

[0143] In this embodiment, for example, a raw material, a nitriding agent, and an inert gas excited to a plasma state are supplied as a first film-forming agent in the first film-forming process, and a first nitride film having compressive stress can be formed on the wafer 200. In this case, for example, a raw material and a nitriding agent are supplied as a second film-forming agent in the second film-forming process, and a second nitride film having tensile stress can be formed on the surface of the first nitride film attached to the inside of the processing chamber.

[0144] In this embodiment as well, the nitriding agent can be excited into a plasma state and supplied in each of the first film formation process and the second film formation process.

[0145] In the first film formation process in this embodiment, as shown in FIG. 6 and the process sequence below, Step E1 of supplying raw material to the wafer 200 in the processing chamber; Step E2 of supplying a nitriding agent excited into a plasma state to the wafer 200 in the processing chamber; Step E3: supplying an inert gas excited into a plasma state to the wafer 200 in the processing chamber; The above-mentioned non-simultaneous cycle is repeated a predetermined number of times (n 4 times, where n 4 is an integer of 1 or more), thereby forming a first nitride film having compressive stress on the wafer 200.

[0146] In the second film formation process in this embodiment, as shown in FIG. 5 and the process sequence below, a step F1 of supplying a source material to the first nitride film deposited in the processing chamber; a step F2 of supplying a nitriding agent excited into a plasma state to the first nitride film deposited inside the processing vessel; The above-mentioned non-simultaneous cycle is repeated a predetermined number of times (n5 times, where n5 is an integer equal to or greater than 1), thereby forming a second nitride film having tensile stress on the surface of the first nitride film adhering to the inside of the processing chamber.

[0147] First film formation process: (raw material → plasma-excited nitriding agent → plasma-excited inert gas) × n4 Second film formation process: (raw material → plasma-excited nitriding agent) × n5

[0148] The processing procedures and processing conditions in steps E1 and F1 may be the same as those in step A1 described above. The processing procedures and processing conditions in steps E2 and F2 may be the same as those in step A2 described above. The processing procedures and processing conditions in step E3 may be the same as those in step B3 described above. Other aspects may be the same as those in the first aspect described above.

[0149] In this embodiment, when a first nitride film having compressive stress is formed in the first film formation process, a second nitride film having tensile stress is formed in the second film formation process, thereby achieving the same effects as the above-described embodiment. That is, by depositing a second nitride film having tensile stress on the surface of the first nitride film having compressive stress, the stress of the film adhering to the inside of the processing chamber can be alleviated, thereby increasing the cumulative film thickness at which film peeling occurs. This allows for a longer cleaning cycle and a shorter downtime of the film formation apparatus, thereby improving the productivity of the film formation process. Furthermore, it is possible to suppress the generation of microparticles, improve the quality of the film formed on the wafer 200, and significantly increase the yield.

[0150] Furthermore, in the first film formation process, as in this embodiment, a raw material, a nitriding agent, and an inert gas excited to a plasma state are supplied as the first film formation agent, thereby making it possible to efficiently form a first nitride film having compressive stress at a low temperature.

[0151] <Third Aspect of the Present Disclosure> In the film formation sequence of this embodiment, similarly to the second embodiment, when a first nitride film having compressive stress is formed in the first film formation process, a second nitride film having tensile stress is formed in the second film formation process.

[0152] In this embodiment, for example, a raw material and an inert gas excited to a plasma state are supplied as a first film-forming agent in the first film-forming process, and a first nitride film having compressive stress can be formed on the wafer 200. In this case, for example, a raw material and a nitriding agent are supplied as a second film-forming agent in the second film-forming process, and a second nitride film having tensile stress can be formed on the surface of the first nitride film attached to the inside of the processing chamber.

[0153] In this embodiment as well, the nitriding agent can be excited into a plasma state and supplied in the second film forming process.

[0154] In the first film formation process in this embodiment, as shown in FIG. 7 and the process sequence below, Step G1 of supplying raw material to the wafer 200 in the processing chamber; Step G2 of supplying an inert gas excited into a plasma state to the wafer 200 in the processing chamber; The above-mentioned non-simultaneous cycle is repeated a predetermined number of times (n6 times, where n6 is an integer of 1 or more), thereby forming a first nitride film having compressive stress on the wafer 200.

[0155] In the second film formation process in this embodiment, as shown in FIG. 5 and the process sequence below, a step H1 of supplying a source material to the first nitride film deposited in the processing vessel; a step H2 of supplying a nitriding agent excited into a plasma state to the first nitride film adhering to the inside of the processing vessel; The above-mentioned non-simultaneous cycle is repeated a predetermined number of times (n7 times, where n7 is an integer of 1 or more), thereby forming a second nitride film having tensile stress on the surface of the first nitride film adhered to the inside of the processing chamber.

[0156] First film formation process: (raw material → plasma-excited inert gas) × n6 Second film formation process: (raw material → plasma-excited nitriding agent) × n7

[0157] The processing procedures and processing conditions in steps G1 and H1 may be the same as those in step A1 described above. In step G1, the raw material containing Si-N bonds exemplified in step C1 described above may be used as the raw material. In step H1, the raw material exemplified in step A1 described above may be used as the raw material. The processing procedures and processing conditions in step G2 may be the same as those in step B3 described above. The processing procedures and processing conditions in step H2 may be the same as those in step A2 described above. Other aspects may be the same as those in the first aspect described above.

[0158] In this embodiment, when a first nitride film having compressive stress is formed in the first film formation process, a second nitride film having tensile stress is formed in the second film formation process, thereby achieving the same effects as the above-described embodiment. That is, by depositing a second nitride film having tensile stress on the surface of the first nitride film having compressive stress, the stress of the film adhering to the inside of the processing chamber can be alleviated, thereby increasing the cumulative film thickness at which film peeling occurs. This allows for a longer cleaning cycle and a shorter downtime of the film formation apparatus, thereby improving the productivity of the film formation process. Furthermore, it is possible to suppress the generation of microparticles, improve the quality of the film formed on the wafer 200, and significantly increase the yield.

[0159] Furthermore, in the first film formation process, as in this embodiment, by supplying a raw material and an inert gas excited to a plasma state as the first film formation agent, a first nitride film having compressive stress can be efficiently formed at a low temperature.

[0160] Furthermore, according to this aspect, the supply of a nitriding agent can be omitted in the first film formation process, thereby shortening the processing time, and as a result, the throughput, i.e., productivity, can be improved.

[0161] <Other Aspects of the Present Disclosure> Although the embodiments of the present disclosure have been specifically described above, the present disclosure is not limited to the above embodiments and can be modified in various ways without departing from the spirit and scope of the present disclosure.

[0162] For example, both a first film formation process for forming a first nitride film having tensile stress and a first film formation process for forming a first nitride film having compressive stress may be performed in the same processing chamber. In this case, both a second film formation process for forming a second nitride film having compressive stress and a second film formation process for forming a second nitride film having tensile stress are performed in the same processing chamber at predetermined times. That is, when a first nitride film having tensile stress is formed on wafer 200 in the first film formation process in the processing chamber, a second nitride film having compressive stress is formed on the surface of the first nitride film having tensile stress attached to the inside of the processing chamber in the second film formation process. Also, when a first nitride film having compressive stress is formed on wafer 200 in the first film formation process in the same processing chamber, a second nitride film having tensile stress is formed on the surface of the first nitride film having compressive stress attached to the inside of the processing chamber in the second film formation process. In these cases, the same effects as those of the various aspects described above can be obtained.

[0163] Furthermore, for example, in the first film formation process, a process for forming a first nitride film having tensile stress and a process for forming a first nitride film having compressive stress may be alternately and continuously repeated to form a film (first stacked nitride film) in which these films are alternately stacked. For example, when a first stacked nitride film having a total tensile stress is formed on the wafer 200 in the first film formation process, a second nitride film having compressive stress is formed on the surface of the first stacked nitride film having a total tensile stress attached to the inside of the processing chamber in the second film formation process. Also, for example, when a first stacked nitride film having a total compressive stress is formed on the wafer 200 in the first film formation process, a second nitride film having tensile stress is formed on the surface of the first stacked nitride film having a total compressive stress attached to the inside of the processing chamber in the second film formation process. In these cases, the same effects as those of the various aspects described above can be obtained.

[0164] Furthermore, for example, in the second film formation process, a process of forming a second nitride film having tensile stress and a process of forming a second nitride film having compressive stress may be alternately and continuously repeated to form a film (second stacked nitride film) in which these films are alternately stacked. For example, when a first nitride film having tensile stress is formed on the wafer 200 in the first film formation process, a second stacked nitride film having a total compressive stress is formed on the surface of the first nitride film having tensile stress attached to the inside of the processing vessel in the second film formation process. Also, for example, when a first nitride film having compressive stress is formed on the wafer 200 in the first film formation process, a second stacked nitride film having a total tensile stress is formed on the surface of the first nitride film having compressive stress attached to the inside of the processing vessel in the second film formation process. In these cases, the same effects as those of the various aspects described above can be obtained.

[0165] The laminated nitride film can be formed, for example, by the following process sequence (x, y, z are each an integer of 1 or more). In this case, the total stress of the laminated nitride film can be adjusted by changing the ratio of x to y (x / y) in the following process sequence, i.e., the thickness T of the nitride film having tensile stress. x The thickness T of the nitride film having compressive stress yRatio to (T x / T y ) can be freely controlled by adjusting. For example, by setting x / y>1(x>y), that is, T x / T y >1(T x >T y ), it becomes easy to make the total stress of the laminated nitride film a tensile stress. <y)とすることにより、すなわち、T x / T y <1(T x <T y ) makes it easy to make the total stress of the laminated nitride film a compressive stress.

[0166] [(raw material → plasma-excited nitriding agent) × x → (raw material → plasma-excited nitriding agent → plasma-excited inert gas) × y] × z

[0167] Furthermore, for example, in the above-described embodiment, an example in which multiple types of film-forming agents are supplied non-simultaneously has been described, but various types of film-forming agents may also be supplied simultaneously. For example, in the above-described first embodiment, the periods during which steps A1 and A2 are performed may be at least partially overlapped to provide a period during which they are performed simultaneously. Furthermore, for example, the periods during which steps B1, B2, and B3 are at least partially overlapped to provide a period during which they are performed simultaneously. These points also apply to the modified examples and other embodiments. In these cases, the same effects as those of the above-described embodiment can be obtained.

[0168] Furthermore, for example, in the above-described embodiment, an example has been described in which the second film formation process is performed with an empty boat 217 housed in the processing vessel, but the second film formation process may also be performed with dummy wafers loaded in the boat 217. If the first film formation process is performed with dummy wafers loaded in the boat 217, a first nitride film will also adhere to the surfaces of the dummy wafers. Therefore, by performing the second film formation process with dummy wafers loaded in the boat 217, it is possible to alleviate the stress of the film adhered to the surfaces of the dummy wafers. In this case, the same effects as those of the above-described embodiment can be obtained.

[0169] Furthermore, for example, in the above-described embodiment, the second film formation process is performed in a state in which the boat 217 is accommodated in the processing vessel, but the second film formation process may be performed in a state in which the lower end opening of the manifold 209 is closed by the shutter 219s without accommodating the boat 217 in the processing vessel. In this case, the same effects as those of the above-described embodiment can be obtained.

[0170] Furthermore, for example, in the above-described embodiment, an example in which silicon nitride films are formed as the first nitride film and the second nitride film has been described, but metal nitride films may also be formed. That is, a source gas containing metal elements such as aluminum (Al), titanium (Ti), hafnium (Hf), zirconium (Zr), tantalum (Ta), molybdenum (Mo), and tungsten (W) is used as a source material, and by the above-described processing sequence, aluminum nitride film (AlN film), titanium nitride film (TiN film), hafnium nitride film (HfN film), zirconium nitride film (ZrN film), tantalum nitride film (TaN film), molybdenum nitride film (Mo The present disclosure can also be applied to the formation of nitride films containing metals, such as tungsten nitride film (WN), tungsten nitride film (WN), aluminum carbonitride film (AlCN film), titanium carbonitride film (TiCN film), hafnium carbonitride film (HfCN film), zirconium carbonitride film (ZrCN film), tantalum carbonitride film (TaCN film), molybdenum carbonitride film (MoCN), tungsten carbonitride film (WCN), titanium aluminum nitride film (TiAlN film), and titanium aluminum carbonitride film (TiAlCN film). The processing procedures and processing conditions for supplying the various film-forming agents can be the same as those in each step of the above-mentioned embodiment. In these cases, the same effects as those of the above-mentioned embodiment can be obtained.

[0171] Furthermore, for example, as a plasma generation method, in addition to capacitively coupled plasma (CCP), inductively coupled plasma (ICP) may be used. In this case, too, the same effects as those of the above-mentioned embodiment can be obtained.

[0172] It is preferable that the recipes used for each process are individually prepared according to the process content and stored in the storage device 121c via an electric communication line or an external storage device 123. Then, when starting each process, it is preferable that the CPU 121a appropriately selects an appropriate recipe according to the process content from among the multiple recipes stored in the storage device 121c. This makes it possible to reproducibly form films with various film types, composition ratios, film qualities, and film thicknesses using a single film formation device. It also reduces the burden on the operator, prevents operational errors, and enables each process to be started quickly.

[0173] The above-mentioned recipes do not necessarily have to be newly created, but may be prepared by modifying an existing recipe already installed in the film forming apparatus. When modifying a recipe, the modified recipe may be installed in the film forming apparatus via an electric communication line or a recording medium on which the modified recipe is recorded. Alternatively, an existing recipe already installed in the film forming apparatus may be directly modified by operating the input / output device 122 provided in the existing film forming apparatus.

[0174] In the above-described various aspects and modifications, examples of forming a film using a batch-type film formation apparatus that processes multiple substrates at a time have been described. The present disclosure is not limited to the above-described various aspects and modifications, and can be suitably applied, for example, to cases where a film is formed using a single-wafer film formation apparatus that processes one or several substrates at a time. Furthermore, in the above-described various aspects and modifications, examples of forming a film using a film formation apparatus having a hot-wall type processing furnace have been described. The present disclosure is not limited to the above-described various aspects and modifications, and can be suitably applied to cases where a film is formed using a film formation apparatus having a cold-wall type processing furnace.

[0175] Even when using these film forming apparatuses, each process can be performed using the same process procedures and conditions as those in the various aspects and variations described above, and the same effects as those in the various aspects and variations described above can be obtained.

[0176] The various aspects and modifications described above can be used in appropriate combinations, and the processing procedures and processing conditions in such combinations can be, for example, the same as those in the various aspects and modifications described above. [Example]

[0177] In Example 1, SiN films were formed on multiple wafers using the film-forming apparatus described above and the process sequence shown in Figure 5 and below. DCS gas was used as the source material, NH gas as the nitriding agent, and N gas as the inert gas. Other process conditions were the same as those in the process conditions described above.

[0178] In Example 2, SiN films were formed on multiple wafers using the film-forming apparatus described above and the process sequence shown in Figure 6 and below. DCS gas was used as the source material, NH gas as the nitriding agent, and N gas as the inert gas. Other process conditions were the same as those in the process conditions described above.

[0179] The stress of the SiN film in Examples 1 and 2 was measured. The results are shown in Figure 10. The horizontal axis of Figure 10 indicates the stress [MPa] of the SiN film, with positive stress representing tensile stress and negative stress representing compressive stress. The vertical axis indicates the processing position of the wafer in the boat, with 0 representing the bottom side and 70 representing the top side. In the figure, the ● symbol indicates Example 1 and the ▲ symbol indicates Example 2.

[0180] 10, it was confirmed that the stress of the SiN film in Example 1 was a tensile stress of about 1200 to 1500 MPa. In contrast, it was confirmed that the stress of the SiN film in Example 2 was a compressive stress of about 1000 to 1300 MPa. In other words, it was confirmed that the stress of the SiN film can be freely controlled by appropriately selecting the processing sequences shown in FIGS. 5 and 6. [Explanation of symbols]

[0181] 200 wafers 201 Processing Room

Claims

1. (a) supplying a source material and a nitriding agent to a substrate accommodated in a processing chamber to form a first nitride film on the substrate; (b) supplying the source material and the nitriding agent to the first nitride film adhered to the inside of the processing vessel in (a), thereby forming a second nitride film on the surface of the first nitride film adhered to the inside of the processing vessel; In (a), (c-1) supplying the raw material into the processing vessel; (c-2) supplying the nitriding agent into the processing vessel; (c-3) supplying an inert gas excited into a plasma state into the processing vessel without supplying the nitriding agent; In the case where the first nitride film having compressive stress is formed by performing a cycle of non-simultaneously performing the above steps, (b) forming the second nitride film having tensile stress by performing (c-1) and (c-2) non-simultaneously and performing a cycle that does not include (c-3); In the case where the first nitride film having tensile stress is formed by performing (c-1) and (c-2) non-simultaneously and performing a cycle not including (c-3) in (a), In (b), a cycle of non-simultaneously performing (c-1), (c-2), and (c-3) is performed to form the second nitride film having compressive stress.

2. In (a), (c-1) and (c-2) are performed non-simultaneously and a cycle not including (c-3) is performed to form the first nitride film having tensile stress; 2. The film forming method according to claim 1, wherein in (b), the second nitride film having compressive stress is formed by performing a cycle of non-simultaneously performing (c-1), (c-2), and (c-3).

3. 3. The film forming method according to claim 2, wherein in step (b), the second nitride film is deposited on the surface of the first nitride film.

4. In (a), the first nitride film having compressive stress is formed by performing a cycle of non-simultaneously performing (c-1), (c-2), and (c-3); 2. The film forming method according to claim 1, wherein in (b), the second nitride film having tensile stress is formed by performing (c-1) and (c-2) non-simultaneously and performing a cycle that does not include (c-3).

5. 5. The film forming method according to claim 4, wherein in step (b), the second nitride film is deposited on the surface of the first nitride film.

6. 6. The film forming method according to claim 1, wherein the nitriding agent is excited to a plasma state and then supplied.

7. The film forming method according to any one of claims 1 to 5, wherein (b) is carried out every time (a) is carried out.

8. The film forming method according to any one of claims 1 to 5, wherein (b) is carried out each time (a) is carried out a plurality of times.

9. 6. The film forming method according to claim 1, wherein (b) is performed without placing the substrate in the processing vessel.

10. (a) is performed in a state where the substrate is supported by a support in the processing chamber; 6. The film forming method according to claim 1, wherein (b) is performed in a state where the support that does not support the substrate is accommodated in the processing vessel.

11. The inert gas is N ２ 6. The film forming method according to claim 1, wherein the gas is at least one of a gas and a rare gas.

12. The film forming method according to claim 1, wherein the inert gas is N 2 gas.

13. A film forming method according to claim 1, wherein the inert gas is a rare gas.

14. 6. The film forming method according to claim 1, wherein the nitriding agent is a gas containing nitrogen and hydrogen.

15. (a) supplying a source material and a nitriding agent to a substrate accommodated in a processing chamber to form a first nitride film on the substrate; (b) supplying the source material and the nitriding agent to the first nitride film adhered to the inside of the processing vessel in (a), thereby forming a second nitride film on the surface of the first nitride film adhered to the inside of the processing vessel; In (a), (c-1) supplying the raw material into the processing vessel; (c-2) supplying the nitriding agent into the processing vessel; (c-3) supplying an inert gas excited into a plasma state into the processing vessel without supplying the nitriding agent; In the case where the first nitride film having compressive stress is formed by performing a cycle of non-simultaneously performing the above steps, (b) forming the second nitride film having tensile stress by performing (c-1) and (c-2) non-simultaneously and performing a cycle that does not include (c-3); In the case where the first nitride film having tensile stress is formed by performing (c-1) and (c-2) non-simultaneously and performing a cycle not including (c-3) in (a), In (b), a cycle of non-simultaneously performing (c-1), (c-2), and (c-3) is performed to form the second nitride film having compressive stress.

16. a processing vessel in which the substrate is processed; a first supply system for supplying a raw material into the processing vessel; a second supply system for supplying a nitriding agent into the processing vessel; a third supply system for supplying an inert gas excited into a plasma state into the processing chamber; In the processing vessel, (a) a process of forming a first nitride film on a substrate accommodated in the processing vessel by supplying the source material and the nitriding agent to the substrate, and (b) a process of forming a second nitride film on a surface of the first nitride film adhered to the processing vessel by supplying the source material and the nitriding agent to the first nitride film adhered to the processing vessel in (a), In (a), (c-1) supplying the raw material into the processing vessel; (c-2) supplying the nitriding agent into the processing vessel; (c-3) supplying an inert gas excited into a plasma state into the processing vessel without supplying the nitriding agent; In the case where the first nitride film having compressive stress is formed by performing a cycle of non-simultaneously performing the above steps, (b) forming the second nitride film having tensile stress by performing (c-1) and (c-2) non-simultaneously and performing a cycle that does not include (c-3); In the case where the first nitride film having tensile stress is formed by performing (c-1) and (c-2) non-simultaneously and performing a cycle not including (c-3) in (a), a control unit configured to be able to control the first supply system, the second supply system, and the third supply system so as to form the second nitride film having compressive stress by performing a cycle of non-simultaneously performing (c-1), (c-2), and (c-3) in (b); A film forming apparatus having the above structure.

17. (a) supplying a source material and a nitriding agent to a substrate accommodated in a processing chamber to form a first nitride film on the substrate; (b) supplying the source material and the nitriding agent to the first nitride film adhered to the inside of the processing vessel in (a), thereby forming a second nitride film on the surface of the first nitride film adhered to the inside of the processing vessel; In (a), (c-1) supplying the raw material into the processing vessel; (c-2) supplying the nitriding agent into the processing vessel; (c-3) supplying an inert gas excited into a plasma state into the processing vessel without supplying the nitriding agent; In the case where the first nitride film having compressive stress is formed by performing a cycle of non-simultaneously performing the above steps, (b) forming the second nitride film having tensile stress by performing (c-1) and (c-2) non-simultaneously and performing a cycle that does not include (c-3); In the case where the first nitride film having tensile stress is formed by performing (c-1) and (c-2) non-simultaneously and performing a cycle not including (c-3) in (a), (b) forming the second nitride film having compressive stress by performing a cycle of non-simultaneously performing (c-1), (c-2), and (c-3); A program that causes a film deposition device to execute the above by a computer.

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