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

Abstract

This film formation method comprises a step for forming a nitride film on a substrate by performing a cycle a predetermined number of times, the cycle including: (a) a step for supplying raw material to the substrate; (b) a step for supplying a nitriding agent to the substrate; and (c) a step for supplying an activated species X to the substrate, the activated species X being generated by plasma-exciting an inert gas. In (c), the amount of the activated species X that is exposed to a surface of the substrate is controlled so that stress in the nitride film is somewhere between tensile stress and compressive stress, or is compressive stress.

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 (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] As semiconductor devices become smaller and more highly integrated, there is a demand for controlling the stress of nitride films with high controllability.

[0005] An object of the present disclosure is to provide a technique that can improve the controllability of the stress in a nitride film. [Means for solving the problem]

[0006] According to one aspect of the present disclosure, (a) supplying a raw material to a substrate; (b) supplying a nitriding agent to the substrate; (c) supplying activated species X generated by plasma-exciting an inert gas to the substrate; a step of forming a nitride film on the substrate by performing a cycle including the steps of: By controlling the amount of exposure of the activated species X to the surface of the substrate in (c), a technique is provided in which the stress of the nitride film is controlled between tensile stress and compressive stress, or is controlled to be compressive stress. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to improve the controllability of the stress in the nitride film. [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 an example of a processing sequence in Modification 8 of the present disclosure. [Figure 7]Figure 7(a) is a partial cross-sectional enlarged view of the surface of a wafer 200 on which a nitride film has been formed in variant example 1, Figure 7(b) is a partial cross-sectional enlarged view of the surface of a wafer 200 on which a nitride film has been formed in variant example 2, Figure 7(c) is a partial cross-sectional enlarged view of the surface of a wafer 200 on which a nitride film has been formed in variant example 3, Figure 7(d) is a partial cross-sectional enlarged view of the surface of a wafer 200 on which a nitride film has been formed in variant example 4, Figure 7(e) is a partial cross-sectional enlarged view of the surface of a wafer 200 on which a nitride film has been formed in variant example 5, and Figure 7(f) is a partial cross-sectional enlarged view of the surface of a wafer 200 on which a nitride film has been formed in variant example 6. [Figure 8] FIG. 10 is a diagram showing the measurement results of stress on nitride films in an example and a comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0009] <One aspect of the present disclosure> Hereinafter, one embodiment of the present disclosure will be described mainly with reference to Figures 1 to 5. Note that all drawings used in the following description are 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] A raw material (source gas) is supplied from the gas supply pipe 232a into the processing chamber 201 via the MFC 241a, the valve 243a, and the nozzle 249a.

[0016] A nitriding agent (nitriding gas, nitrogen source) as a reactant (reaction gas) is supplied from the gas supply pipe 232b into the processing chamber 201 via the MFC 241b, the valve 243b, and the nozzle 249b.

[0017] An oxidizing agent (oxidizing gas, oxygen source) as a reactant (reaction gas) is supplied from the gas supply pipe 232c 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 supplied after being plasma-excited in the processing chamber 201. In this case, the inert gas can also act as a modifying gas.

[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. At least one of the nitriding agent supply system and the oxidizing agent supply system can also be referred to as a reactant supply system. 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. As described above, when an inert gas acts as a modifying gas, the inert gas supply system can also be referred to as a modifying gas supply system.

[0020] Any or all of the various gas supply systems described above may be configured as an integrated gas supply system 248 in which valves 243a-243f, MFCs 241a-241f, etc. are integrated. The integrated gas supply system 248 is connected to each of the gas supply pipes 232a-232f, and is configured so that the supply operation of 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 gas 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 gas 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 plasma. Hereinafter, the act of exciting the gas into plasma 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. Control programs for controlling the operation of the film forming apparatus, process recipes describing the procedures and conditions of the processes described below, etc., are readably recorded and stored in the storage device 121c. 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 recipes, control programs, etc. are collectively referred to simply as programs. The process recipes are also simply referred to as recipes. 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. It has been completed.

[0039] The controller 121 can be configured by installing the above-mentioned program recorded and 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 simply 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 for forming a nitride film on a wafer 200 as a substrate, i.e., a film formation sequence, using the above-described film formation apparatus as one step in the manufacturing process of a semiconductor device will be described. In the following description, the operation of each part of the film formation apparatus is controlled by a controller 121.

[0041] In the processing sequence of this embodiment shown in FIG. (a) supplying raw materials to the wafers 200 in the processing chamber; (b) supplying a nitriding agent to the wafer 200 in the processing chamber; (c) supplying activated species X generated by plasma-exciting an inert gas to the wafer 200 in the processing chamber; a predetermined number of times (n times, n is an integer of 1 or more) to form a nitride film on the wafer 200; By controlling the amount of exposure of the activated species X to the surface of the wafer 200 in (c), the stress of the nitride film is controlled between tensile stress (tensile stress) and compressive stress (compressive stress), or is controlled to be compressive stress.

[0042] In the processing sequence shown in FIG. 5, (b) shows an example in which activated species Y generated by plasma-exciting a nitriding agent are supplied to the wafer 200.

[0043] In this specification, for convenience, such a processing sequence (gas supply sequence) may be expressed as follows: Similar notations will be used in the following descriptions of other aspects and modifications.

[0044] (raw material → plasma-excited nitriding agent → plasma-excited inert gas) × n

[0045] The process sequence shown in FIG. 5 illustrates an example in which a cycle of (a), (b), and (c) is performed in this order is repeated multiple times (n times). In this case, n is an integer greater than or equal to 2. FIG. 5 also illustrates an example in which, after performing (a) and before performing (b), the space in which the wafer 200 exists (inside the process vessel) is purged with an inert gas. Note that, after performing (b) and before performing (c), the process vessel may be purged with an inert gas in a non-plasma atmosphere. Furthermore, when performing the cycle multiple times, the process vessel may be purged with an inert gas in a non-plasma atmosphere after performing (c) and before performing (a). At least one of these methods can prevent the mixing of gases in a plasma state in the process vessel, resulting in unintended reactions and particle generation. These process sequences can be expressed as follows. Note that, purging performed in a non-plasma atmosphere is indicated by P below.

[0046] (raw material → P → plasma-excited nitriding agent → plasma-excited inert gas) × n (raw material → P → plasma-excited nitriding agent → P → plasma-excited inert gas) × n (raw material → P → plasma-excited nitriding agent → plasma-excited inert gas → P) × n (raw material → P → plasma-excited nitriding agent → P → plasma-excited inert gas → P) × n

[0047] The nitride film in this disclosure includes not only a silicon nitride film (SiN film) but also a nitride film containing carbon (C) or oxygen (O). That is, the nitride film includes a silicon nitride film (SiN film), a silicon carbonitride film (SiCN film), a silicon oxynitride film (SiON film), a silicon oxycarbonitride film (SiOCN film), etc. Below, an example of forming a SiN film as a nitride film will be described.

[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] (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.

[0050] (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.

[0051] (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.

[0052] (film formation process) Then, the following steps 1, 2, and 3 are executed in sequence.

[0053] [Step 1] In step 1, raw materials are supplied to the wafer 200 in the processing chamber 201.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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 2, and to prevent unintended reactions (for example, gas-phase reactions or plasma-gas-phase reactions) and particle generation that may result from this.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] As the raw material, in addition to the chlorosilane-based gas, for example, a fluorosilane-based gas such as tetrafluorosilane (SiF4) gas or difluorosilane (SiH2F2) gas, a bromosilane-based gas such as tetrabromosilane (SiBr4) gas or dibromosilane (SiH2Br2) gas, or an iodosilane-based gas such as tetraiodosilane (SiI4) gas or diiodosilane (SiH2I2) gas can be used. One or more of these can be used as the raw material. You can be there.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] [Step 2] After step 1 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.

[0067] 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.

[0068] 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 Y generated by the plasma-excited nitriding agent are supplied to the wafer 200 (plasma-excited nitriding agent supply). At this time, the nitriding agent containing activated species Y is supplied to the wafer 200.

[0069] When a gas containing nitrogen (N) and hydrogen (H) is used as the nitriding agent, the N and H-containing gas is plasma-excited to form NHx * (x is an integer of 1 to 3) and other activated species Y 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 active species Y such as the above is supplied. Note that * means a radical. The same applies to the following explanation.

[0070] 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 non-plasma-excited nitriding agent may be pre-flowed (non-plasma-excited nitriding agent pre-flow). In this case, the nitriding agent 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 supply of the nitriding agent is continued. This results in a more stable plasma. It is possible to generate reactive species.

[0071] 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.

[0072] 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 1.

[0073] After the SiN layer is formed, the valve 243b is closed to stop the supply of the nitriding agent into the processing chamber 201. Then, step 3 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 by a processing procedure similar to the purging in step 1 (purging). 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 3, and to prevent unintended reactions (e.g., plasma gas-phase reactions) and particle generation due to this.

[0074] As the nitriding agent, for example, a nitrogen (N) and hydrogen (H) containing gas can be used. The N and H containing gas is also an N containing gas and an H containing gas. The nitriding agent preferably has an N-H bond.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] [Step 3] After step 2 is completed, an inert gas is plasma-excited and supplied to the wafer 200 in the processing chamber 201, that is, to the SiN layer formed on the wafer 200.

[0079] 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).

[0080] 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 activated species X generated by the plasma-excitation of the inert gas are supplied to the wafer 200 (plasma-excited inert gas supply). At this time, the inert gas containing the activated species X is supplied to the wafer 200.

[0081] 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 X are generated and supplied to the wafer 200 (plasma-excited N2 gas supply). * , N2 * N2 gas containing activated species X such as

[0082] 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 X such as the above is supplied.

[0083] 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 X such as

[0084] 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.

[0085] Before supplying the inert gas to the wafer 200 after plasma excitation, a period of time during which the inert gas is supplied without plasma excitation may be provided. That is, before supplying the plasma-excited inert gas to the wafer 200, 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.

[0086] 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.

[0087] The SiN layer formed on the wafer 200 is modified by supplying an inert gas to the wafer 200 in a plasma-excited state under the above-described processing conditions. During this process, impurities such as Cl remaining in the SiN layer are converted into a gaseous substance containing at least Cl during the process of the SiN layer modification reaction by the activated species X, and the gaseous substance is 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 2. Furthermore, due to this modification, the SiN layer modified in this step has a shorter interatomic distance between Si and N contained in the layer than the SiN layer formed in step 2. 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 2.

[0088] If the processing pressure is less than 2 Pa, the N2 generated together with the activated species X when the inert gas is excited into plasma will + , Ar + , He + The amount of ions generated increases rapidly, causing excessive ion attack on the wafer 200 and possibly reducing the wet etching resistance of the nitride film finally formed on the wafer 200. By setting the processing pressure to 2 Pa or higher, it is possible to reduce the amount of ions generated, suppress ion attack, and avoid a reduction in the wet etching resistance of the nitride film finally formed on the wafer 200. By setting the processing pressure to 2.66 Pa or higher, the above-mentioned effects can be more fully obtained. By setting the processing pressure to 3 Pa or higher, the above-mentioned effects can be even more fully obtained.

[0089] If the processing pressure exceeds 6 Pa, the lifetime of the activated species X generated when the inert gas is excited into plasma is shortened, making it difficult for the activated species X to reach the center of the wafer 200, which may reduce the uniformity of wet-etching resistance within the wafer surface of the nitride film finally formed on the wafer 200. By setting the processing pressure to 6 Pa or less, the lifetime of the activated species X is extended, allowing the activated species X to reach the entire surface of the wafer 200, and making it possible to avoid a reduction in the uniformity of wet-etching resistance within the wafer surface of the nitride film finally formed on the wafer 200. By setting the processing pressure to 5.32 Pa or less, the above-mentioned effects can be more fully obtained. By setting the processing pressure to 4 Pa ​​or less, the above-mentioned effects can be even more fully obtained.

[0090] For the above reasons, it is desirable to lower the processing pressure in this step to 2 Pa or more and 6 Pa or less, preferably 2.66 Pa or more and 5.32 Pa or less, and more preferably 3 Pa or more and 4 Pa ​​or less. In this case, it is preferable to lower the processing pressure in this step than the processing pressure in steps 1 and 2. Note that such a lower processing pressure can be promoted by lowering the flow rate of the inert gas supplied in this step compared to the flow rate of the inert gas supplied in purging. FIG. 5 shows an example in which a lower processing pressure is promoted by lowering the flow rate of the inert gas supplied in this step compared to the flow rate of the inert gas supplied in purging.

[0091] Due to the modification reaction by the nitriding agent in step 2, the content of impurities such as Cl in the SiN layer formed in step 2 is reduced compared to the content of impurities such as Cl in the Si-containing layer formed in step 1. However, impurities such as Cl, for example, at about several atomic %, may remain in the SiN layer formed in step 2 without being completely removed by the modification reaction by the nitriding agent. In this step, the impurities such as Cl that remain in the SiN layer without being completely removed by the modification reaction by the nitriding agent can be removed by the activated species X.

[0092] 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 to the wafer 200 is stopped. When the above cycle is repeated multiple times, after step 3 is completed, step 1 is performed again. 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 1 (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 1, and thereby prevent unintended reactions (e.g., gas-phase reactions or plasma-gas-phase reactions) and particle generation.

[0093] 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, and one or more of these can be used as the inert gas.

[0094] [Perform the cycle a specified number of times] By performing the above-described steps 1, 2, and 3 asynchronously, i.e., by repeating a predetermined number of cycles (n times, where n is an integer greater than or equal to 1), a nitride film, such as 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 repeat the above-described cycle multiple times until the thickness of the SiN layer formed per cycle is thinner than the desired film thickness and 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), for example, can also be formed in step 2. By performing the above-described cycle a predetermined number of times, a nitride film, such as a silicon carbonitride film (SiCN film), can also be formed on the surface of the wafer 200.

[0095] (After purging and atmospheric pressure recovery) After the process of forming a 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).

[0096] (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).

[0097] (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).

[0098] (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).

[0099] This completes the series of processes for forming a film on the wafer 200. This series of processes is performed a predetermined number of times.

[0100] The stress of the nitride film formed on the wafer 200 tends to be tensile stress. In contrast, according to this embodiment, by controlling the amount of exposure of the activated species X to the surface of the wafer 200 in step 3, it is possible to control the stress of the nitride film formed on the wafer 200 between tensile stress and compressive stress, or to control it to be compressive stress.

[0101] The amount of exposure of the activated species X to the surface of the wafer 200 in step 3 can be controlled by the exposure time of the activated species X to the surface of the wafer 200 in step 3 and the processing pressure in step 3, as exemplified below. By using at least one of these, it becomes possible to control the stress of the nitride film formed on the wafer 200 as described above.

[0102] For example, by making the exposure time of the activated species X to the surface of the wafer 200 in step 3 longer than the exposure time of the raw material to the surface of the wafer 200 in step 1, the amount of exposure of the activated species X to the surface of the wafer 200 in step 3 can be appropriately increased, and the stress of the nitride film formed on the wafer 200 can be controlled as described above. Also, by making the exposure time of the activated species X to the surface of the wafer 200 in step 3 longer than the exposure time of the nitriding agent to the surface of the wafer 200 in step 2, the amount of exposure of the activated species X to the surface of the wafer 200 in step 3 can be appropriately increased, and the stress of the nitride film formed on the wafer 200 can be controlled as described above. Also, by making the exposure time of the activated species X to the surface of the wafer 200 in step 3 longer than the purging time performed after performing step 1 and before performing step 2, the amount of exposure of the activated species X to the surface of the wafer 200 in step 3 can be appropriately increased, and the stress of the nitride film can be controlled as described above.

[0103] Furthermore, for example, when activated species Y generated by plasma-exciting a nitriding agent is supplied to the wafer 200 in step 2, the amount of exposure of activated species X to the surface of the wafer 200 in step 3 can be increased appropriately by making it larger than the amount of exposure of activated species Y to the surface of the wafer 200 in step 2, and the stress of the nitride film formed on the wafer 200 can be controlled as described above. Furthermore, the amount of exposure of activated species X to the surface of the wafer 200 in step 3 can be increased appropriately by making the exposure time of activated species X to the surface of the wafer 200 in step 3 longer than the exposure time of activated species Y to the surface of the wafer 200 in step 2, and the stress of the nitride film formed on the wafer 200 can be controlled as described above.

[0104] Furthermore, for example, by setting the processing pressure in step 3 lower than the processing pressure in step 2, it is possible to lengthen the lifetime of the activated species X generated in step 3. This makes it possible to appropriately increase the amount of exposure of the activated species X to the surface of the wafer 200 in step 3, and to control the stress of the nitride film formed on the wafer 200 as described above.

[0105] The exposure time of the activated species X to the surface of the wafer 200 in step 3 can be set to a time during which the stress of the nitride film formed on the wafer 200 is between tensile stress and compressive stress, or can be set to a time during which the stress of the nitride film formed on the wafer 200 is between tensile stress and compressive stress. Also, the processing pressure in step 3 can be set to a pressure during which the stress of the nitride film formed on the wafer 200 is between tensile stress and compressive stress, or can be set to a pressure during which the stress of the nitride film formed on the wafer 200 is compressive stress.

[0106] (3) Effects of this mode According to this aspect, one or more of the following effects can be obtained.

[0107] (a) By controlling the amount of exposure of the activated species X to the surface of the wafer 200 in step 3, the stress of the nitride film, which tends to become tensile stress, can be freely controlled between tensile stress and compressive stress, or can be controlled to be compressive stress. This allows nitride films that meet various film stress requirements to be formed in various locations in semiconductor devices, thereby improving device characteristics and performance. Furthermore, being able to freely control the stress of the nitride film allows for a wider range of applications for the nitride film. Furthermore, being able to freely control the stress of the nitride film reduces warpage of the wafer 200 after the nitride film is formed, thereby preventing deterioration in processing accuracy in the subsequent photolithography process.

[0108] (b) By making the exposure time of the activated species X to the surface of the wafer 200 in step 3 longer than the exposure time of the raw material to the surface of the wafer 200 in step 1, the amount of exposure of the activated species X to the surface of the wafer 200 in step 3 can be appropriately increased, and the stress of the nitride film can be more effectively controlled, for example, to be compressive stress.

[0109] By making the exposure time of the active species X to the surface of the wafer 200 in step 3 longer than the exposure time of the nitriding agent to the surface of the wafer 200 in step 2, the exposure amount of the active species X to the surface of the wafer 200 in step 3 can be appropriately increased, and the same effect as that described above can be obtained.

[0110] By making the exposure time of the activated species X to the surface of the wafer 200 in step 3 longer than the purging time performed after performing step 1 and before performing step 2, the amount of exposure of the activated species X to the surface of the wafer 200 in step 3 can be appropriately increased, and the same effect as that described above can be obtained.

[0111] In step 2, when the activated species Y generated by plasma-exciting the nitriding agent is supplied to the wafer 200, by making the amount of the activated species X exposed to the surface of the wafer 200 in step 3 larger than the amount of the activated species Y exposed to the surface of the wafer 200 in step 2, the amount of the activated species X exposed to the surface of the wafer 200 in step 3 can be appropriately increased, and the same effect as that described above can be obtained.

[0112] In step 2, when the activated species Y generated by plasma-exciting the nitriding agent is supplied to the wafer 200, the exposure time of the activated species X to the surface of the wafer 200 in step 3 is set to be longer than the exposure time of the activated species Y to the surface of the wafer 200 in step 2, whereby the exposure amount of the activated species X to the surface of the wafer 200 in step 3 can be appropriately increased, and the same effect as that described above can be obtained.

[0113] By making the pressure of the space in which the wafer 200 exists in step 3 lower than the pressure of the space in which the wafer 200 exists in step 2, the amount of exposure of the activated species X to the surface of the wafer 200 in step 3 can be appropriately increased, and the same effect as that described above can be obtained.

[0114] (c) The above-mentioned effect is particularly pronounced when the inert gas is at least one of N2 gas and a rare gas.

[0115] Furthermore, the above-mentioned effect is particularly pronounced when the raw material contains halogen and Si and the nitriding agent contains N and H.

[0116] Furthermore, the above-mentioned effects are particularly pronounced when the raw material is a halosilane-based gas, the nitriding agent is a hydrogen nitride-based gas, the inert gas is at least one of N2 gas and a rare gas, and the nitride film is a SiN film.

[0117] (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.

[0118] (Variation 1) The amount of exposure of the activated species X to the surface of the wafer 200 in step 3 (exposure time or processing pressure) may be varied for each predetermined cycle, thereby finely adjusting the stress of the nitride film in the thickness direction of the nitride film. That is, the amount of exposure of the activated species X to the surface of the wafer 200 in step 3 may be varied between a cycle in at least one of the early and late stages of film formation and a cycle in other stages, thereby finely adjusting the stress of the nitride film partially in accordance with the stress of an underlying film of the nitride film and the stress of other films (hereinafter simply referred to as other films) to be formed on the nitride film.

[0119] For example, in step 3, by making the exposure time of the activated species X to the surface of the wafer 200 in the cycle at the beginning of film formation longer than the exposure time of the activated species X to the surface of the wafer 200 in the cycles at other times (middle and late film formation), it is possible to control the stress of at least the portion of the nitride film that comes into contact with the base film to be compressive stress. Also, for example, by making the process pressure in the cycle at the beginning of film formation lower than the process pressure in the cycles at other times (middle and late film formation), it is possible to control the stress of the nitride film in the same manner as described above. Also, for example, by combining these techniques, it is possible to control the stress of the nitride film in the same manner as described above.

[0120] In this modified example, the same effects as those of the above embodiment can be obtained.

[0121] Furthermore, according to this modification, as shown in FIG. 7(a), when the stress of the underlying film of the nitride film is tensile stress, the stress of at least the portion of the nitride film that contacts the underlying film can be controlled to be compressive stress, thereby alleviating or canceling out the stress of the underlying film. It is also possible to reduce the stress of the nitride film itself. Furthermore, it is possible to alleviate the stress of the accumulated film adhering to the inside of the processing chamber, suppress peeling of the accumulated film, and extend the maintenance cycle of the film forming apparatus. Furthermore, when the stress of the underlying film of the nitride film is tensile stress, the stress of the underlying film can be alleviated or canceled out by controlling the stress of the nitride film itself (the entire nitride film) to be compressive stress.

[0122] (Variation 2) As in the first modification, the amount of exposure of the activated species X to the surface of the wafer 200 (exposure time or processing pressure) may be varied for each predetermined cycle, so that the stress of the nitride film can be finely adjusted in the thickness direction of the nitride film.

[0123] For example, in step 3, by making the exposure time of the activated species X to the surface of the wafer 200 in the cycle in the later stage of film formation longer than the exposure time of the activated species X to the surface of the wafer 200 in the cycles in the other stages (initial and middle stages of film formation), it is possible to control the stress of at least the portion of the nitride film that comes into contact with another film to be formed on the nitride film to be compressive stress. Also, for example, by making the processing pressure in the cycle in the later stage of film formation lower than the processing pressure in the cycles in the other stages (initial and middle stages of film formation) in step 3, it is possible to control the stress of the nitride film in the same manner as described above. Also, for example, by combining these techniques, it is possible to control the stress of the nitride film to be It is possible to control it in the same way as described above.

[0124] In this modified example, the same effects as those of the above embodiment can be obtained.

[0125] Furthermore, according to this modification, as shown in FIG. 7(b), when the stress of another film to be formed on a nitride film is tensile stress, the stress of at least the portion of the nitride film that contacts the other film can be controlled to be compressive stress, thereby alleviating or canceling out the stress of the other film. It is also possible to reduce the stress of the nitride film itself. Furthermore, it is possible to alleviate the stress of the accumulated film adhering to the inside of the processing chamber, suppress peeling of the accumulated film, and extend the maintenance cycle of the film forming apparatus. Furthermore, when the stress of another film to be formed on a nitride film is tensile stress, the stress of the other film can be alleviated or canceled out by controlling the stress of the nitride film itself (the entire nitride film) to be compressive stress.

[0126] (Variation 3) As in the first modification, the amount of exposure of the activated species X to the surface of the wafer 200 (exposure time or processing pressure) may be varied for each predetermined cycle, so that the stress of the nitride film can be finely adjusted in the thickness direction of the nitride film.

[0127] For example, in step 3, by making the exposure time of the activated species X to the surface of the wafer 200 in the cycles at the beginning and end of film formation longer than the exposure time of the activated species X to the surface of the wafer 200 in the cycles at other times (middle of film formation), it is possible to control the stress of at least a portion of the nitride film that contacts the base film and the stress of at least a portion of the nitride film that contacts another film formed on the nitride film to be compressive stress. Also, for example, by making the process pressure in the cycles at the beginning and end of film formation lower than the process pressure in the cycles at other times (middle of film formation), it is possible to control the stress of the nitride film in the same manner as described above. Also, for example, by combining these techniques, it is possible to control the stress of the nitride film in the same manner as described above.

[0128] In this modified example, the same effects as those of the above embodiment can be obtained.

[0129] According to this modification, as shown in FIG. 7( c), when the stress of the underlying film of the nitride film is tensile stress, the stress of at least the portion of the nitride film in contact with the underlying film is controlled to be compressive stress. When the stress of another film to be formed on the nitride film is tensile stress, the stress of at least the portion of the nitride film in contact with the other film is controlled to be compressive stress. This allows the stress of the underlying film and the other film to be alleviated or offset. It also reduces the stress of the nitride film itself. Furthermore, it also reduces the stress of the accumulated film adhering to the inside of the processing chamber, suppresses peeling of the accumulated film, and extends the maintenance cycle of the film forming apparatus. When the stress of the underlying film of the nitride film and the other film to be formed on the nitride film are both tensile stress, the stress of the nitride film itself (the entire nitride film) can be controlled to be compressive stress, thereby alleviating or offsetting the stress of the underlying film and the other film.

[0130] (Variation 4) As in the first modification, the amount of exposure of the activated species X to the surface of the wafer 200 (exposure time or processing pressure) may be varied for each predetermined cycle, so that the stress of the nitride film can be finely adjusted in the thickness direction of the nitride film.

[0131] For example, in step 3, by shortening the exposure time of the activated species X to the surface of the wafer 200 in the cycles at the beginning and end of film formation compared to the exposure time of the activated species X to the surface of the wafer 200 in the other cycles (middle film formation), it is possible to control the stress of at least a portion of the nitride film that contacts the base film and the stress of at least a portion of the nitride film that contacts another film formed on the nitride film to be tensile stress. Also, for example, by increasing the process pressure in the cycles at the beginning and end of film formation compared to the process pressure in the other cycles (middle film formation), it is possible to control the stress of the nitride film in the same manner as described above. Also, for example, by combining these techniques, it is possible to control the stress of the nitride film in the same manner as described above.

[0132] In this modified example, the same effects as those of the above embodiment can be obtained.

[0133] Furthermore, according to this modification, as shown in FIG. 7(d), when the stress of the underlying film of the nitride film is compressive, the stress of at least the portion of the nitride film in contact with the underlying film is controlled to be tensile stress. When the stress of another film to be formed on the nitride film is compressive, the stress of at least the portion of the nitride film in contact with the other film is controlled to be tensile stress. This makes it possible to alleviate or cancel out the stresses of the underlying film and the other film. It is also possible to reduce the stress of the nitride film itself. Furthermore, it is possible to alleviate the stress of the accumulated film adhering to the inside of the processing chamber, suppress peeling of the accumulated film, and extend the maintenance cycle of the film forming apparatus. Furthermore, when the stress of the underlying film of the nitride film and the stress of the other film to be formed on the nitride film are both compressive, it is also possible to alleviate or cancel out the stresses of the underlying film and the other film by controlling the stress of the nitride film itself (the entire nitride film) to be tensile stress.

[0134] (Variation 5) As in the first modification, the amount of exposure of the activated species X to the surface of the wafer 200 (the exposure time of the activated species X in step 3 or the processing pressure in step 3) may be varied for each predetermined cycle, so as to finely adjust the stress of the nitride film in the thickness direction of the nitride film.

[0135] For example, in step 3, by gradually increasing the exposure time of the activated species X to the surface of the wafer 200 per predetermined cycle from the early stage of film formation to the later stage of film formation, the stress of at least a portion of the nitride film that contacts the base film (bottom side) can be set to tensile stress, and the stress of at least a portion of the nitride film that contacts another film formed on the nitride film (top side) can be set to compressive stress, so that the stress of the nitride film gradually changes from tensile stress to compressive stress as it moves from the bottom side to the top side. Furthermore, for example, by gradually decreasing the processing pressure per predetermined cycle from the early stage of film formation to the later stage of film formation in step 3, the stress of the nitride film can be controlled in a similar manner to the above. Furthermore, for example, by combining these techniques, the stress of the nitride film can be controlled in a similar manner to the above.

[0136] In this modified example, the same effects as those of the above embodiment can be obtained.

[0137] Furthermore, according to this modification, as shown in FIG. 7(e), when the stress of the underlying film of the nitride film is compressive stress, the stress of at least the portion of the nitride film that contacts the underlying film is controlled to be tensile stress, and when the stress of another film formed on the nitride film is tensile stress, the stress of at least the portion of the nitride film that contacts the other film is controlled to be compressive stress, thereby making it possible to alleviate or offset the stress of the underlying film and the other film. It is also possible to reduce the stress of the nitride film itself. Furthermore, it is possible to alleviate the stress of the accumulated film adhering to the inside of the processing chamber, suppress peeling of the accumulated film, and lengthen the maintenance cycle of the film forming apparatus. It is also possible.

[0138] In this modification, it is not necessary to control the stress of the nitride film so that it gradually changes from tensile stress to compressive stress as it moves from the bottom side to the top side. The same effect as described above can be obtained by setting the stress of at least the portion of the nitride film that contacts the base film to tensile stress and the stress of at least the portion of the nitride film that contacts another film formed on the nitride film to compressive stress.

[0139] (Variation 6) As in the first modification, the amount of exposure of the activated species X to the surface of the wafer 200 (the exposure time of the activated species X in step 3 or the processing pressure in step 3) may be varied for each predetermined cycle, so as to finely adjust the stress of the nitride film in the thickness direction of the nitride film.

[0140] For example, in step 3, by gradually shortening the exposure time of the activated species X to the surface of the wafer 200 per predetermined cycle from the early stage of film formation to the later stage of film formation, the stress of at least a portion of the nitride film that contacts the base film (bottom side) can be set to compressive stress, and the stress of at least a portion of the nitride film that contacts another film formed thereon (top side) can be set to tensile stress, and the stress of the nitride film can be controlled so that it gradually changes from compressive stress to tensile stress as it moves from the bottom side to the top side. Furthermore, for example, by gradually increasing the processing pressure per predetermined cycle from the early stage of film formation to the later stage of film formation in step 3, the stress of the nitride film can be controlled in a similar manner to the above. Furthermore, for example, by combining these techniques, the stress of the nitride film can be controlled in a similar manner to the above.

[0141] In this modified example, the same effects as those of the above embodiment can be obtained.

[0142] Furthermore, according to this modification, as shown in FIG. 7(f), when the stress of the underlying film of the nitride film is tensile stress, the stress of at least the portion of the nitride film that contacts the underlying film is controlled to be compressive stress, and when the stress of another film formed on the nitride film is compressive stress, the stress of at least the portion of the nitride film that contacts the other film is controlled to be tensile stress. This makes it possible to alleviate or cancel out the stress of the underlying film and the other film. It is also possible to reduce the stress of the nitride film itself. Furthermore, it is possible to alleviate the stress of the accumulated film adhering to the inside of the processing chamber, suppress peeling of the accumulated film, and extend the maintenance cycle of the film forming apparatus.

[0143] In this modification, it is not necessary to control the stress of the nitride film so that it gradually changes from compressive stress to tensile stress as it moves from the bottom side to the top side. The same effect as described above can be obtained by setting the stress of at least the portion of the nitride film that contacts the base film to compressive stress and the stress of at least the portion of the nitride film that contacts another film formed on the nitride film to tensile stress.

[0144] (Variation 7) Using the stress control technique shown in the above-described modified example, when the stress of the underlying film of the nitride film is tensile stress, the stress of at least the portion of the nitride film that comes into contact with the underlying film may be controlled to be tensile stress, and when the stress of the underlying film is compressive stress, the stress of at least the portion of the nitride film that comes into contact with the underlying film may be controlled to be compressive stress.

[0145] Furthermore, by using the stress control technique shown in the above-described modified example, when the stress of another film formed on the nitride film is tensile stress, the stress of at least the portion of the nitride film that comes into contact with the other film may be controlled to be tensile stress, and when the stress of the other film is compressive stress, the stress of at least the portion of the nitride film that comes into contact with the other film may be controlled to be compressive stress.

[0146] In this modification, the same effects as those of the above-described embodiment can be obtained. Furthermore, according to this modification, the directions of the stress of the nitride film and the stress of the film in contact with the nitride film (the base film or other film formed on the nitride film) are aligned, so that it is possible to suppress film peeling caused by stress at the interface between these films.

[0147] (Variation 8) By using a raw material containing Si-N bonds as the raw material, the raw material can function not only as a Si source but also as a nitrogen source, and the supply of a nitriding agent can be omitted. That is, in the film formation process, a SiN film may be formed on the wafer 200 by the process sequence shown in FIG. 6 and below.

[0148] (raw material → P → plasma-excited inert gas → P) × n

[0149] in this case, (a) supplying raw materials to the wafers 200 in the processing chamber; (c) supplying activated species X generated by plasma-exciting an inert gas to the wafer 200 in the processing chamber; A film can be formed on the wafer 200 by performing a predetermined number of cycles including the steps (a) and (c). The above-described processing sequence shows an example in which cycles of (a) and (c) are alternately (non-simultaneously) performed a predetermined number of times, with a step of purging the processing vessel between them. As in the above-described embodiment, purging before and after supplying the plasma-excited inert gas can also be omitted. Also, FIG. 6 shows an example in which the flow rate of the inert gas supplied in (c) is reduced below the flow rate of the inert gas supplied in purging, thereby promoting a reduction in the processing pressure. .

[0150] Even in this case, by controlling the amount of exposure of the activated species X to the surface of the wafer 200 in (c), the stress of the nitride film can be controlled between tensile stress and compressive stress, or can be controlled to be compressive stress.

[0151] The raw materials in this modification, i.e., raw materials containing Si-N bonds, can be 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 can be used as the raw material. Of these, it is preferable to use TSA containing three Si-N bonds as the raw material. These raw materials can be supplied to the wafer 200 from the raw material supply system described above. The processing conditions can be the same as those in step 1 of the processing sequence of the above-described embodiment.

[0152] The inert gas in this modification may be N2 gas or a rare gas such as Ar gas, He gas, Ne gas, or Xe gas, similar to the inert gas in step 3 of the processing sequence of the above embodiment. 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. The processing conditions may be the same as those in step 3 of the processing sequence of the above embodiment.

[0153] This modification also provides the same effects as the above-described embodiment. Furthermore, this modification can omit the supply of a nitriding agent, thereby shortening the processing time. As a result, it is possible to improve throughput, i.e., productivity.

[0154] (Variation 9) As in the process sequence shown below, in (b), the nitriding agent may be supplied without being excited into plasma.

[0155] (raw material → P → nitriding agent → plasma-excited inert gas) × n (raw material → P → nitriding agent → P → plasma-excited inert gas) × n (raw material → P → nitriding agent → plasma-excited inert gas → P) × n (raw material → P → nitriding agent → P → plasma-excited inert gas → P) × n

[0156] In this modified example, the same effects as those of the above embodiment can be obtained.

[0157] (Variation 10) The above-described cycle may further include a step of supplying an oxidizing agent to the wafer 200. In this case, it is possible to form a silicon oxynitride film (SiON film) on the wafer 200. In this case, the oxidizing agent may be supplied to the wafer 200 without being plasma-excited, or may be supplied after being plasma-excited. That is, in the film formation process, a SiON film may be formed on the wafer 200 by the process sequence shown below. Note that, as in the above embodiment, purging before and after supplying the plasma-excited inert gas may be omitted.

[0158] (raw material → P → oxidizer → P → plasma-excited nitriding agent → P → plasma-excited inert gas → P) × n (raw material → P → plasma-excited nitriding agent → P → oxidizing agent → P → plasma-excited inert gas → P) × n (raw material → P → plasma-excited nitriding agent → P → plasma-excited inert gas → P → oxidizing agent → P) × n (raw material → P → plasma-excited oxidizing agent → P → plasma-excited nitriding agent → P → plasma-excited inert gas → P) × n (raw material → P → plasma-excited nitriding agent → P → plasma-excited oxidizing agent → P → plasma-excited inert gas → P) × n (raw material → P → plasma-excited nitriding agent → P → plasma-excited inert gas → P → plasma-excited oxidizing agent → P) × n

[0159] In these cases, an oxidizing agent can be supplied to the wafer 200 from the above-described oxidizing agent supply system. The processing conditions can be the same as those in step 2 of the processing sequence of the above-described embodiment. A hydrogen (H)-containing gas may be supplied together with the oxidizing agent. The H-containing gas can be supplied from, for example, a raw material supply system or a nitriding agent supply system.

[0160] Examples of oxidizing agents that can be used include oxygen (O2) gas, ozone (O3) gas, water vapor (HO gas), hydrogen peroxide (HO2) gas, nitrous oxide (NO) gas, nitric oxide (NO2) gas, nitrogen dioxide (NO2) gas, carbon monoxide (CO) gas, carbon dioxide (CO2) gas, etc. One or more of these can be used as the oxidizing agent.

[0161] When supplying an H-containing gas together with the oxidizer, the H-containing gas may be, for example, hydrogen (H2) gas or deuterium ( 2 H2) gas, etc. can be used. 2 H2 gas is also called D2 gas. One or more of these gases can be used as the H-containing gas.

[0162] In this modification, the same effects as those of the above-described embodiment can be obtained. That is, even if the cycle further includes a step of supplying an oxidizing agent to the wafer 200 and forming a SiON film on the wafer 200, the same effects as those of the above-described embodiment can be obtained.

[0163] The above-described cycle in Modification 8 may further include a step of supplying an oxidizing agent to the wafer 200. In this case, it is also possible to form a SiON film on the wafer 200. In this case, the oxidizing agent may be supplied to the wafer 200 without being plasma-excited, or may be supplied after being plasma-excited. That is, in the film formation process, a SiON film may be formed on the wafer 200 by the process sequence shown below. In this case, as in the above embodiment, purging before and after supplying the plasma-excited inert gas may also be omitted.

[0164] (raw material → P → oxidant → P → plasma-excited inert gas → P) × n (raw material → P → plasma-excited inert gas → P → oxidant → P) × n (raw material → P → plasma-excited oxidant → P → plasma-excited inert gas → P) × n (raw material → P → plasma-excited inert gas → P → plasma-excited oxidant → P) × n

[0165] In these cases, the same effects as those of the above-described embodiment and Modification 8 can be obtained. That is, even when the cycle further includes a step of supplying an oxidizing agent to the wafer 200 and forming a SiON film on the wafer 200, the same effects as those of the above-described embodiment and Modification 8 can be obtained.

[0166] <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.

[0167] For example, as in the processing sequence in the above-described embodiment, steps 1, 2, and 3 are considered as one cycle and this cycle is performed in this order a predetermined number of times (n times, where n is an integer equal to or greater than 1), but the order in which each step is performed may also be changed as in the processing sequence shown below. In these cases, the same effects as in the above-described embodiment can be obtained.

[0168] (Step 1 → Step 2 → Step 3) × n (Step 2 → Step 3 → Step 1) × n (Step 3 → Step 1 → Step 2) × n

[0169] However, if the final step in the cycle is step 1 or step 2, the composition and modification effect of the outermost surface of the film that is finally formed may differ from those of the remaining portions. Therefore, as in the processing sequence shown below, it is preferable to perform step 2 or step 3 after the final cycle is completed, and fine-tune the film quality of the outermost surface of the film that is finally formed so that the degree of nitriding by step 2 and the degree of modification by step 3 are equivalent to those of the layers formed up to that point.

[0170] (Step 2 → Step 3 → Step 1) × n → Step 2 → Step 3 (Step 3 → Step 1 → Step 2) × n → Step 3

[0171] Furthermore, for example, as in the processing sequence in the above-described embodiment, steps 1, 2, and 3 constitute one cycle and this cycle is performed a predetermined number of times (n times, n is an integer of 1 or greater), or steps 1 and 2 may be performed multiple times (m times, m is an integer of 2 or greater) and then step 3 may be performed, and this cycle may be performed a predetermined number of times (n times, n is an integer of 1 or greater). Also, after performing step 1, steps 2 and 3 may be performed multiple times (m times, m is an integer of 2 or greater), and this cycle may be performed a predetermined number of times (n times, n is an integer of 1 or greater). These processing sequences can be expressed as follows. In these cases, the same effects as those of the above-described embodiment can be obtained.

[0172] (Step 1 → Step 2 → Step 3) × n [(Step 1 → Step 2) × m → Step 3] × n [Step 1 → (Step 2 → Step 3) × m] × n

[0173] 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.

[0174] It is preferable that the recipes used for each process are individually prepared according to the process content and recorded 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 the multiple recipes recorded and 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.

[0175] 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.

[0176] 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.

[0177] 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.

[0178] 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]

[0179] In Examples 1 to 3, a SiN film was formed on a wafer using the film formation apparatus according to the above-described embodiment by a process sequence that performed a predetermined number of cycles including steps 1 to 3. DCS gas was used as the raw material, NH gas as the nitriding agent, and N gas as the inert gas. The supply time of activated species X in step 3 was set to 5 seconds, 20 seconds, and 60 seconds, respectively. Other process conditions were common to the process conditions in the above-described embodiment.

[0180] As a comparative example, a SiN film was formed on a wafer using the film formation apparatus of the above-described embodiment by a processing sequence in which steps 1 and 2 were alternately performed a predetermined number of times. In the comparative example, step 3 was not performed. DCS gas was used as the raw material, and NH3 gas was used as the nitriding agent. The processing conditions were the same as those in the example.

[0181] The stress of the SiN film was measured in each of Examples 1 to 3 and the Comparative Example. The results are shown in Fig. 8. The horizontal axis of Fig. 8 represents the supply time (seconds) of activated species X in step 3, and the vertical axis represents the stress [MPa] of the SiN film. Note that 0 seconds on the horizontal axis means that step 3 was not performed (Comparative Example). Also, positive stress on the vertical axis represents tensile stress, and negative stress represents compressive stress.

[0182] 8, it was confirmed that the stress of the SiN film in the comparative example (supply time of active species X: 0 second) was a tensile stress of about 1500 MPa. In contrast, it was confirmed that the stress of the SiN film in Examples 1 to 3 was a tensile stress of about 500 MPa, a compressive stress of about 800 MPa, and a compressive stress of about 1250 MPa, respectively. That is, it was confirmed that by performing step 3 and controlling the amount of exposure of active species X to the wafer surface in step 3, it was possible to control the stress of the SiN film between tensile stress and compressive stress, or to control it to be compressive stress.

[0183] <Preferred aspects of the present disclosure> Other preferred aspects of the present disclosure will be noted below.

[0184] (Appendix 1) According to another aspect of the present disclosure, (a) supplying a raw material to a substrate; (c) supplying activated species X generated by plasma-exciting an inert gas to the substrate; a step of forming a nitride film on the substrate by performing a cycle including the steps of: There is provided a film forming method or a semiconductor device manufacturing method in which the stress of the nitride film is controlled between tensile stress and compressive stress, or controlled to be compressive stress, by controlling the amount of exposure of the activated species X to the surface of the substrate in (c).

[0185] (Appendix 2) According to yet another aspect of the present disclosure, a processing chamber in which the substrate is processed; a raw material supply system that supplies raw materials to the substrate in the processing chamber; an inert gas supply system for supplying an inert gas to the substrate in the processing chamber; an excitation unit that excites the gas into plasma; a control unit configured to be able to control the raw material supply system, the inert gas supply system, and the excitation unit so as to perform each treatment (each step) of Appendix 1 in the treatment chamber; A deposition apparatus having the following is provided.

[0186] (Appendix 3) According to yet another aspect of the present disclosure, A program for causing a film forming apparatus to execute each procedure (each step) of Supplementary Note 1 by a computer, or a computer-readable recording medium on which the program is recorded, is provided. [Explanation of symbols]

[0187] 200 wafers 201 Processing Room

Claims

1. (a) supplying a raw material to a substrate; (b) supplying a nitriding agent containing hydrogen to the substrate; (c) supplying activated species X generated by plasma-exciting an inert gas to the substrate while not supplying the nitriding agent containing hydrogen; a step of forming a nitride film on the substrate by performing a cycle of non-simultaneously performing the above a predetermined number of times; (c) A film forming method in which the stress of the nitride film is controlled to be between tensile stress and compressive stress, or controlled to be compressive stress, by controlling the amount of exposure of the activated species X to the surface of the substrate.

2. 2. The film forming method according to claim 1, wherein the stress of the nitride film is controlled to be compressive stress by controlling the exposure time of the activated species X to the surface of the substrate in (c).

3. 2. The film forming method according to claim 1, wherein the exposure time of the activated species X to the surface of the substrate in (c) is longer than the exposure time of the raw material to the surface of the substrate in (a).

4. 2. The film forming method according to claim 1, wherein the exposure time of the activated species X to the surface of the substrate in (c) is longer than the exposure time of the nitriding agent to the surface of the substrate in (b).

5. After performing (a) and before performing (b), a step of purging the space in which the substrate is present is included; 2. The film forming method according to claim 1, wherein the exposure time of the activated species X to the surface of the substrate in (c) is longer than the purging time.

6. 6. The film forming method according to claim 1, wherein in step (b), activated species Y generated by plasma-exciting the nitriding agent are supplied to the substrate.

7. 7. The film forming method according to claim 6, wherein the amount of exposure of the activated species X to the surface of the substrate in (c) is set to be greater than the amount of exposure of the activated species Y to the surface of the substrate in (b).

8. 6. The film forming method according to claim 1, wherein the exposure time of the activated species X to the surface of the substrate in (c) is set to a time during which the stress of the nitride film becomes compressive stress.

9. 6. The film forming method according to claim 1, wherein the pressure in the space where the substrate is present in (c) is set lower than the pressure in the space where the substrate is present in (b).

10. 6. The film forming method according to claim 1, wherein the pressure in the space where the substrate is present in (c) is set to 2 Pa or more and 6 Pa or less.

11. 6. The film forming method according to claim 1, wherein the exposure time of the activated species X to the surface of the substrate in (c) is varied for each predetermined cycle.

12. 6. The film formation method according to claim 1, wherein the exposure time of the activated species X to the surface of the substrate in (c) is made different between a cycle in at least one of an early stage and a late stage of film formation and a cycle in other stages.

13. When the stress of the underlying film of the nitride film is a tensile stress, the stress of at least a portion of the nitride film that contacts the underlying film is controlled to be a compressive stress; 6. The film forming method according to claim 1, wherein when the stress of the underlayer is compressive stress, the stress of at least a portion of the nitride film that is in contact with the underlayer is controlled to be tensile stress.

14. When the stress of another film formed on the nitride film is a tensile stress, the stress of at least a portion of the nitride film that contacts the other film is controlled to be a compressive stress; When the stress of the other film is compressive stress, at least one of the nitride films 6. The film forming method according to claim 1, wherein the stress of at least the portion in contact with the other film is controlled to be a tensile stress.

15. The inert gas is N ２ The film forming method according to any one of claims 1 to 5, wherein the gas is a gas.

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

17. 6. The film forming method according to claim 1, wherein the raw material contains a halogen and silicon.

18. 6. The film forming method according to claim 1, wherein the raw material is a halosilane-based gas, the nitriding agent is a hydrogen nitride-based gas, the inert gas is at least one of N2 gas and a rare gas, and the nitride film is a silicon nitride film.

19. (a) supplying a raw material to a substrate; (b) supplying a nitriding agent containing hydrogen to the substrate; (c) supplying activated species X generated by plasma-exciting an inert gas to the substrate while not supplying the nitriding agent containing hydrogen; a step of forming a nitride film on the substrate by performing a cycle of non-simultaneously performing the above a predetermined number of times; (c) A method for manufacturing a semiconductor device, wherein the stress of the nitride film is controlled to be between tensile stress and compressive stress, or controlled to be compressive stress, by controlling the amount of exposure of the activated species X to the surface of the substrate.

20. a raw material supply system that supplies raw materials to the substrate; a nitriding agent supply system for supplying a nitriding agent containing hydrogen to the substrate; an inert gas supply system for supplying an inert gas to the substrate; an excitation unit that excites the gas into plasma; a control unit configured to be able to control the raw material supply system, the nitriding agent supply system, the inert gas supply system, and the excitation unit so as to perform a process of forming a nitride film on the substrate by performing a predetermined number of cycles of non-simultaneously performing (a) a process of supplying the raw material to the substrate, (b) a process of supplying the nitriding agent containing hydrogen to the substrate, and (c) a process of supplying activated species X generated by plasma-exciting the inert gas to the substrate while not supplying the nitriding agent containing hydrogen to the substrate, and to control the stress of the nitride film to be between tensile stress and compressive stress or to be compressive stress by controlling the amount of exposure of the activated species X to the surface of the substrate in (c); A film forming apparatus having the above structure.

21. (a) supplying a raw material to a substrate; (b) supplying a nitriding agent containing hydrogen to the substrate; (c) supplying activated species X generated by plasma-exciting an inert gas to the substrate while not supplying the nitriding agent containing hydrogen; a step of forming a nitride film on the substrate by performing a cycle of non-simultaneously performing the above a predetermined number of times; (c) controlling the amount of exposure of the activated species X to the surface of the substrate to control the stress of the nitride film between tensile stress and compressive stress, or to compressive stress; A program that causes a film deposition device to execute the above by a computer.

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