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

Abstract

The present application can form a film having flatness. A multilayer metal-containing film is formed on a substrate by alternately performing a process of forming a metal-containing film on a substrate and a process of supplying a processing gas to the substrate to perform either or both of a process of forming a crystal layer separation film on the surface of the metal-containing film and a process of removing abnormal growth nuclei on the surface of the metal-containing film.

Description

TECHNICAL FIELD

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

[0002] As a word line of a NAND type flash memory, a DRAM having a 3-dimensional structure, for example, a tungsten (W) film having a low resistance is used. In addition, a titanium nitride (TiN) film serving as a barrier film is sometimes provided between the W film and an insulating film (for example, refer to Patent Document 1 and Patent Document 2). The TiN film has an effect of improving adhesion of the W film to the insulating film, and a nucleation film for growing the W film is formed on the TiN film.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT DOCUMENTS

[0005] Patent Document 1: Japanese Patent Application Publication No. 2011-66263

[0006] Patent Document 2: International Publication No. 2019 / 058608 SUMMARY

[0007] PROBLEMS TO BE SOLVED BY THE INVENTION

[0008] However, the filling width of the trench in which the W film is formed becomes fine, and if the TiN film is not flat, the volume of the W film decreases, and it is difficult to achieve low resistance of the W film.

[0009] An object of the present disclosure is to provide a technology capable of forming a film having flatness.

[0010] METHOD FOR SOLVING PROBLEMS

[0011] According to one embodiment of the present disclosure, a technology is provided in which a multilayer metal-containing film is formed on a substrate by alternately performing a process of forming the metal-containing film on the substrate and a process of forming a crystal layer separation film on a surface of the metal-containing film or removing an abnormal growth nucleus on the surface of the metal-containing film by supplying a processing gas to the substrate.

[0012] EFFECT OF THE INVENTION

[0013] According to the present disclosure, a film having flatness can be formed. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 is a schematic longitudinal sectional view showing a longitudinal processing furnace of a substrate processing apparatus in one embodiment of the present disclosure.

[0015] Figure 2 is Figure 1A rough cross-sectional view of the middle AA line.

[0016] Figure 3 This is a schematic configuration diagram of the controller of the substrate processing apparatus in one embodiment of the present disclosure, and is a block diagram showing the control system of the controller.

[0017] Figure 4 This is a diagram showing the film-forming process in the first embodiment of this disclosure.

[0018] Figure 5 This is a diagram showing the film-forming process in the second embodiment of this disclosure.

[0019] Figure 6 This is a diagram showing the film-forming process in the third embodiment of this disclosure.

[0020] Figure 7 This is a diagram showing the film-forming process in the fourth embodiment of this disclosure.

[0021] Figure 8 This is a diagram showing a modified example of the film-forming process in the film-forming flow of the embodiments of the present disclosure.

[0022] Figure 9 (A) and (B) are schematic longitudinal cross-sectional views showing the processing furnace of the substrate processing apparatus in other embodiments of the present disclosure.

[0023] Figure 10 This is a diagram showing a comparison of cross-sections of the TiN films formed on the substrate in the comparative examples and Examples 1-3. Detailed Implementation

[0024] The following is for reference Figures 1-4 Please provide an explanation.

[0025] (1) Composition of substrate processing device

[0026] The substrate processing apparatus 10 includes a processing furnace 202 equipped with a heater 207, which serves as a heating unit (heating mechanism, heating system). The heater 207 is cylindrical in shape and is vertically mounted, supported by a heater base (not shown) that serves as a holding plate.

[0027] On the inner side of the heater 207, an outer tube 203 constituting a reaction vessel (processing vessel) is arranged concentrically with the heater 207. The outer tube 203 is constituted of a heat-resistant material such as quartz (SiO2), silicon carbide (SiC), and the like, and is formed in a cylindrical shape with the upper end closed and the lower end open. A header (inlet flange) 209 is arranged concentrically with the outer tube 203 on the lower side of the outer tube 203. The header 209 is constituted of a metal such as stainless steel (SUS), and is formed in a cylindrical shape with the upper end and the lower end open. An O-ring 220a is provided as a sealing member between the upper end portion of the header 209 and the outer tube 203. The header 209 is supported by the heater base, and thus the outer tube 203 is in a vertically installed state.

[0028] On the inner side of the outer tube 203, an inner tube 204 constituting a reaction vessel is arranged. The inner tube 204 is constituted of a heat-resistant material such as quartz (SiO2), SiC, and the like, and is formed in a cylindrical shape with the upper end closed and the lower end open. The processing vessel (reaction vessel) is mainly constituted of the outer tube 203, the inner tube 204, and the header 209. A processing chamber 201 is formed in the cylindrical hollow portion of the processing vessel (the inner side of the inner tube 204).

[0029] The processing chamber 201 is configured to be capable of housing wafers 200 as substrates in a state in which the wafers 200 are arranged in multiple stages in the vertical direction in a horizontal attitude by a wafer boat 217 to be described later.

[0030] In the processing chamber 201, nozzles 410, 420, 430, 440, 450 are provided to penetrate the side wall of the header 209 and the inner tube 204. The nozzles 410, 420, 430, 440, 450 are respectively connected to gas supply pipes 310, 320, 330, 340, 350. However, the processing furnace 202 of the present embodiment is not limited to the above-described mode.

[0031] In the gas supply pipes 310, 320, 330, 340, 350, mass flow controllers (MFCs) 312, 322, 332, 342, 352 as flow controllers (flow control portions) are respectively provided in order from the upstream side. In addition, valves 314, 324, 334, 344, 354 as on-off valves are respectively provided in the gas supply pipes 310, 320, 330, 340, 350. Downstream of the valves 314, 324, 334, 344, 354 of the gas supply pipes 310, 320, 330, 340, 350, gas supply pipes 510, 520, 530, 540, 550 that supply non-active gas are respectively connected. In the gas supply pipes 510, 520, 530, 540, 550, MFCs 512, 522, 532, 542, 552 as flow controllers (flow control portions) and valves 514, 524, 534, 544, 554 as on-off valves are respectively provided in order from the upstream side.

[0032] The nozzles 410, 420, 430, 440, 450 are provided so as to extend from the lower region of the processing chamber 201 to the upper region of the processing chamber 201, and a plurality of gas supply holes 410a, 420a, 430a, 440a, 450a are provided at positions opposite to the wafers 200, respectively. Thereby, the processing gas is supplied from the gas supply holes 410a, 420a, 430a, 440a, 450a of the nozzles 410, 420, 430, 440, 450 to the wafers 200, respectively. The gas supply holes 410a, 420a, 430a, 440a, 450a are provided a plurality of times from the lower portion to the upper portion of the inner pipe 204, have the same opening area, and are further provided at the same opening pitch. However, the gas supply holes 410a, 420a, 430a, 440a, 450a are not limited to the above-described manner. For example, the opening area can be gradually increased from the lower portion to the upper portion of the inner pipe 204. Thereby, the flow rate of the gas supplied from the gas supply holes 410a, 420a, 430a, 440a, 450a can be more uniformized.

[0033] The gas supply holes 410a, 420a, 430a, 440a, 450a of the nozzles 410, 420, 430, 440, 450 are provided a plurality of times at the height positions of the lower portion to the upper portion of the wafer boat 217 described later. Therefore, the processing gas supplied from the gas supply holes 410a, 420a, 430a, 440a, 450a of the nozzles 410, 420, 430, 440, 450 into the processing chamber 201 can be supplied to the entire region of the wafers 200 housed from the lower portion to the upper portion of the wafer boat 217. The nozzles 410, 420, 430, 440, 450 can be provided so as to extend from the lower region to the upper region of the processing chamber 201, but are preferably provided so as to extend to the vicinity of the top of the wafer boat 217.

[0034] The gas supply holes 410a, 420a, 430a, 440a, 450a of the nozzles 410, 420, 430, 440, 450 are provided a plurality of times at the height positions of the lower portion to the upper portion of the wafer boat 217 described later. Therefore, the processing gas supplied from the gas supply holes 410a, 420a, 430a, 440a, 450a of the nozzles 410, 420, 430, 440, 450 into the processing chamber 201 can be supplied to the entire region of the wafers 200 housed from the lower portion to the upper portion of the wafer boat 217. The nozzles 410, 420, 430, 440, 450 can be provided so as to extend from the lower region to the upper region of the processing chamber 201, but are preferably provided so as to extend to the vicinity of the top of the wafer boat 217.

[0035] A raw material gas containing a metal element (metal-containing gas) as a processing gas is supplied from the gas supply pipe 310 to the processing chamber 201 via the MFC 312, the valve 314, and the nozzle 410. As the raw material, for example, titanium tetrachloride (TiCl4) containing titanium (Ti) as a metal element and serving as a halogen-based raw material (halogen compound, halogen-based titanium raw material) is used.

[0036] A silicon-containing gas as a processing gas is supplied from the gas supply pipe 320 to the processing chamber 201 via the MFC 322, the valve 324, and the nozzle 420. As the silicon-containing gas, for example, a silane-based gas or a chlorosilane-based gas can be used. As the silane-based gas, a silane (SiH4)-based gas can be used. In addition, as the chlorosilane-based gas, a hexachlorodisilane (Si2Cl6)-based gas can be used. Here, the silane-based gas and the chlorosilane-based gas are gases in which the amounts of Si, H, and Cl in the above-described gases are different.

[0037] A reaction gas as a processing gas is supplied from the gas supply pipe 330 to the processing chamber 201 via the MFC 332, the valve 334, and the nozzle 430. As the reaction gas, for example, ammonia (NH3) gas as an N-containing gas containing nitrogen (N) can be used.

[0038] An oxygen-containing gas as a processing gas is supplied from the gas supply pipe 340 to the processing chamber 201 via the MFC 342, the valve 344, and the nozzle 440. As the oxygen-containing gas, for example, oxygen (O2) gas, ozone (O3) gas, nitric oxide (NO) gas, nitrous oxide (N2O) gas, or the like can be used.

[0039] A halogen-containing gas as a processing gas is supplied from the gas supply pipe 350 to the processing chamber 201 via the MFC 352, the valve 354, and the nozzle 450. The halogen-containing gas uses, for example, tungsten hexafluoride (WF6) gas as a gas containing a metal element. As the halogen-containing gas, nitrogen trifluoride (NF3) gas, chlorine trifluoride (ClF3) gas, fluorine (F2) gas, hydrogen fluoride (HF) gas, or the like can also be used.

[0040] A non-active gas such as nitrogen (N2) gas is supplied from the gas supply pipes 510, 520, 530, 540, and 550 to the processing chamber 201 via the MFCs 512, 522, 532, 542, and 552, the valves 514, 524, 534, 544, and 554, and the nozzles 410, 420, 430, 440, and 450, respectively. Hereinafter, an example in which N2 gas is used as a non-active gas will be described, but as the non-active gas, in addition to N2 gas, for example, an inert gas such as argon (Ar) gas, helium (He) gas, neon (Ne) gas, xenon (Xe) gas, or the like can also be used.

[0041] The processing gas supply system is mainly composed of the gas supply pipes 310, 320, 330, 340, 350, the MFCs 312, 322, 332, 342, 352, the valves 314, 324, 334, 344, 354, and the nozzles 410, 420, 430, 440, 450. It is also possible to consider the nozzles 410, 420, 430, 440, 450 alone as the processing gas supply system. The processing gas supply system can also be referred to simply as the gas supply system. The raw material gas supply system is mainly composed of the gas supply pipe 310, the MFC 312, and the valve 314 when the raw material gas is supplied from the gas supply pipe 310. It is also possible to consider the nozzle 410 as included in the raw material gas supply system. Further, the silicon-containing gas supply system is mainly composed of the gas supply pipe 320, the MFC 322, and the valve 324 when the silicon-containing gas is supplied from the gas supply pipe 320. It is also possible to consider the nozzle 420 as included in the silicon-containing gas supply system. Further, the reaction gas supply system is mainly composed of the gas supply pipe 330, the MFC 332, and the valve 334 when the reaction gas is supplied from the gas supply pipe 330. It is also possible to consider the nozzle 430 as included in the reaction gas supply system. When the nitrogen-containing gas is supplied as the reaction gas from the gas supply pipe 330, the reaction gas supply system can also be referred to as the nitrogen-containing gas supply system. Further, the oxygen-containing gas supply system is mainly composed of the gas supply pipe 340, the MFC 342, and the valve 344 when the oxygen-containing gas is supplied from the gas supply pipe 340. It is also possible to consider the nozzle 440 as included in the oxygen-containing gas supply system. Further, the halogen-containing gas supply system is mainly composed of the gas supply pipe 350, the MFC 352, and the valve 354 when the halogen-containing gas is supplied from the gas supply pipe 350. It is also possible to consider the nozzle 450 as included in the halogen-containing gas supply system. Further, the non-active gas supply system is mainly composed of the gas supply pipes 510, 520, 530, 540, 550, the MFCs 512, 522, 532, 542, 552, and the valves 514, 524, 534, 544, 554.

[0042] In the gas supply method of this embodiment, the gas is delivered via the nozzles 410, 420, 430, 440, 450 disposed in the preliminary chamber 201a in the annular longitudinal space defined by the inner wall of the inner tube 204 and the end portions of the plurality of wafers 200. Also, the gas is ejected into the inner tube 204 from the plurality of gas supply holes 410a, 420a, 430a, 440a, 450a provided at positions of the nozzles 410, 420, 430, 440, 450 opposite the wafers. In more detail, the source gas and the like are ejected in a direction parallel to the surface of the wafer 200 through the gas supply hole 410a of the nozzle 410, the gas supply hole 420a of the nozzle 420, the gas supply hole 430a of the nozzle 430, the gas supply hole 440a of the nozzle 440, and the gas supply hole 450a of the nozzle 450.

[0043] The exhaust hole (exhaust port) 204a is a through hole formed in the side wall of the inner tube 204 at a position opposite the nozzles 410, 420, 430, 440, 450, for example, a slit-shaped through hole elongated in the vertical direction. The gas supplied from the gas supply holes 410a, 420a, 430a, 440a, 450a of the nozzles 410, 420, 430, 440, 450 into the processing chamber 201 and flowing over the surface of the wafer 200 flows into the exhaust passage 206 via the exhaust hole 204a, the exhaust passage 206 being constituted by the gap formed between the inner tube 204 and the outer tube 203. Also, the gas flowing into the exhaust passage 206 flows into the exhaust pipe 231 and is exhausted to the outside of the processing furnace 202.

[0044] The exhaust hole 204a is provided at a position opposite the plurality of wafers 200, and the gas supplied from the gas supply holes 410a, 420a, 430a, 440a, 450a into the processing chamber 201 near the wafers 200 flows in the horizontal direction and then flows into the exhaust passage 206 via the exhaust hole 204a. The exhaust hole 204a is not limited to the case where it is constituted by a slit-shaped through hole, but can be constituted by a plurality of holes.

[0045] In the manifold 209, an exhaust pipe 231 that exhausts the atmosphere in the processing chamber 201 is provided. The exhaust pipe 231 is connected, in order from the upstream side, to a pressure sensor 245 that is a pressure detector (pressure detection section) that detects the pressure in the processing chamber 201, an APC (Auto Pressure Controller) valve 243, and a vacuum pump 246 that is a vacuum exhaust device. The APC valve 243 is capable of vacuum exhaust and stopping of vacuum exhaust in the processing chamber 201 by opening and closing the valve in a state in which the vacuum pump 246 is operating, and is further capable of adjusting the pressure in the processing chamber 201 by adjusting the valve opening degree in a state in which the vacuum pump 246 is operating. The exhaust system is mainly composed of the exhaust hole 204a, the exhaust path 206, the exhaust pipe 231, the APC valve 243, and the pressure sensor 245. It is also possible to consider including the vacuum pump 246 in the exhaust system.

[0046] Below the manifold 209, a seal cap 219 that is a furnace port cover that can airtightly occlude the lower end opening of the manifold 209 is provided. The seal cap 219 is configured to abut against the lower end of the manifold 209 from the vertically lower side. The seal cap 219 is composed of, for example, a metal material such as SUS and is formed in a disc shape. On the upper surface of the seal cap 219, an O-ring 220b that is a sealing member that abuts against the lower end of the manifold 209 is provided. On the side of the seal cap 219 opposite the processing chamber 201, a rotation mechanism 267 that rotates the wafer cassette 217 that accommodates the wafer 200 is provided. A rotation shaft 255 of the rotation mechanism 267 penetrates the seal cap 219 and is connected to the wafer cassette 217. The rotation mechanism 267 is configured to rotate the wafer 200 by rotating the wafer cassette 217. The seal cap 219 is configured to be raised and lowered in the vertical direction by a wafer cassette elevator 115 that is a lifting mechanism vertically provided outside the reaction tube 203. The wafer cassette elevator 115 is configured to be capable of carrying the wafer cassette 217 into and out of the processing chamber 201 by raising and lowering the seal cap 219. The wafer cassette elevator 115 is a transport device (transport mechanism) that carries the wafer cassette 217 and the wafer 200 accommodated in the wafer cassette 217 into and out of the processing chamber 201.

[0047] The wafer boat 217 as a substrate support is configured to arrange a plurality of (for example, 25 to 200) wafers 200 in a state of being aligned with each other in a horizontal attitude and in a vertical direction with a space therebetween. The wafer boat 217 is configured of a heat-resistant material such as quartz, SiC, or the like. In the lower portion of the wafer boat 217, a heat insulating plate 218 configured of a heat-resistant material such as quartz, SiC, or the like is supported in a horizontal attitude in a plurality of stages (not shown). With this configuration, heat from the heater 207 is less likely to be transmitted to the side of the seal cap 219. However, the present embodiment is not limited to the above-described configuration. For example, the heat insulating plate 218 can not be provided in the lower portion of the wafer boat 217, and a heat insulating cylinder configured of a cylindrical member of a heat-resistant material such as quartz, SiC, or the like can be provided.

[0048] As shown in FIG. 1, the temperature sensor 263 as a temperature detector is provided in the inner tube 204. The temperature sensor 263 is configured in an L shape, and is provided along the inner wall of the inner tube 204. Figure 2 As shown in FIG. 1, the temperature sensor 263 as a temperature detector is provided in the inner tube 204. The temperature sensor 263 is configured in an L shape, and is provided along the inner wall of the inner tube 204.

[0049] As shown in FIG. 1, the temperature sensor 263 as a temperature detector is provided in the inner tube 204. The temperature sensor 263 is configured in an L shape, and is provided along the inner wall of the inner tube 204. Figure 3 As shown in FIG. 1, the controller 121 as a control unit is configured as a computer having a CPU (Central Processing Unit) 121a, a RAM (Random Access Memory) 121b, a storage device 121c, and an I / O interface 121d. The RAM 121b, the storage device 121c, and the I / O interface 121d are configured to exchange data with the CPU 121a via an internal bus. The controller 121 is connected to an input / output device 122 configured as a touch panel or the like.

[0050] The storage device 121c is constituted by, for example, a flash memory, an HDD (Hard Disk Drive), or the like. In the storage device 121c, a control program that controls the operation of the substrate processing apparatus, a process recipe in which processes, conditions, and the like of the manufacturing method of the semiconductor device described later are described, and the like are stored and can be read out. The process recipe is a program that functions by combining each process (each step) in the manufacturing method of the semiconductor device described later so that a predetermined result is obtained by the controller 121. Hereinafter, these process recipes, control programs, and the like are simply referred to as programs. In the present specification, when the term "program" is used, only the process recipe alone is included at times, only the control program alone is included at times, and a combination of the process recipe and the control program is included at times. The RAM 121b is constituted as a storage area (work area) in which the program, data, and the like read out by the CPU 121a are temporarily stored.

[0051] The I / O interface 121d is connected to the MFCs 312, 322, 332, 342, 352, 512, 522, 532, 542, 552, the valves 314, 324, 334, 344, 354, 514, 524, 534, 544, 554, the pressure sensor 245, the APC valve 243, the vacuum pump 246, the heater 207, the temperature sensor 263, the rotation mechanism 267, the wafer boat lifter 115, and the like described above.

[0052] The CPU 121a is constituted to read out the control program from the storage device 121c and execute it, and to read out the recipe and the like from the storage device 121c in response to an input of an operation instruction from the input / output device 122 and the like. The CPU 121a is also constituted to control, in accordance with the content of the recipe read out, the flow rate adjustment operation of each gas by the MFCs 312, 322, 332, 342, 352, 512, 522, 532, 542, 552, the opening and closing operation of the valves 314, 324, 334, 344, 354, 514, 524, 534, 544, 554, the opening and closing operation of the APC valve 243, and the pressure adjustment operation based on the pressure sensor 245 by the APC valve 243, the temperature adjustment operation of the heater 207 based on the temperature sensor 263, the start and stop of the vacuum pump 246, the rotation and rotation speed adjustment operation of the wafer boat 217 by the rotation mechanism 267, the raising and lowering operation of the wafer boat 217 by the wafer boat lifter 115, the accommodation operation of the wafer 200 into the wafer boat 217, and the like.

[0053] The controller 121 can be constituted by installing the above program stored in the external storage device (e.g., a magnetic tape, a floppy (registered trademark) disk, a hard disk, an optical disk such as a CD, a DVD, a magneto-optical disk such as an MO, a USB memory, a memory card, a semiconductor memory, or the like) 123 into the computer. The storage device 121c and the external storage device 123 are constituted as a recording medium that can be read by the computer. Hereinafter, these are simply collectively referred to as a recording medium. The recording medium in this specification sometimes includes only the storage device 121c alone, sometimes includes only the external storage device 123 alone, or sometimes includes both of them. The program is provided to the computer, and can be performed without using the external storage device 123, but by using a communication method such as the Internet, a dedicated line, or the like.

[0054] (2) Substrate processing step

[0055] As one step of a manufacturing step of a semiconductor device (apparatus), a TiN film is formed on a wafer 200. Figure 4 An example of a step of forming a TiN film on the wafer 200 will be described. The step of forming a TiN film is performed using the processing furnace 202 of the above-described substrate processing apparatus 10. In the following description, the operation of each part constituting the substrate processing apparatus 10 is controlled by the controller 121.

[0056] In the substrate processing step (manufacturing step of a semiconductor device) according to the present embodiment, a multilayer TiN film is formed on the wafer 200 by alternately performing the following steps:

[0057] (a) a step of forming a TiN film as a metal-containing film on the wafer 200, and

[0058] (b) a step of supplying a processing gas to the wafer 200, and performing either or both of a crystal layer separation film formation step of forming a crystal layer separation film on the surface of the TiN film and a abnormal growth nucleus removal step of removing an abnormal growth nucleus on the surface of the TiN film.

[0059] Further, in the crystal layer separation film formation step, as the processing gas, an O2 gas as an oxygen-containing gas is supplied, the pressure at the time of supplying the O2 gas is made different for each cycle, or a SiH4 gas as a silicon-containing gas is supplied.

[0060] Further, in the abnormal growth nucleus removal step, as the processing gas, a WF6 gas as a halogen-containing gas and a metal element-containing gas is supplied.

[0061] Here, during the formation of the TiN film, abnormal growth nuclei grow simultaneously with the crystal growth of TiN. In this embodiment, whenever a TiN film of a predetermined thickness is formed, a crystal layer separator is formed on the surface of the TiN film, thereby preventing the crystal growth of the TiN film. As a result, the abnormal growth nuclei stop growing, and the surface of the TiN film is planarized. Furthermore, whenever a TiN film of a predetermined thickness is formed, the abnormal growth nuclei formed on the surface of the TiN film are removed (etched), thereby planarizing the surface of the TiN film. At this time, the surface of the TiN film is also etched. It should be noted that the term "TiN crystal growth" sometimes also means the growth of TiN grains. During the formation of the TiN film, multiple crystals (grains) typically grow. Sometimes, abnormal growth nuclei form among these multiple crystals.

[0062] In this specification, the term "wafer" sometimes means "the wafer itself" and sometimes means "a laminate of a wafer and a predetermined layer, film, etc., formed on its surface." Similarly, the term "wafer surface" sometimes means "the surface of the wafer itself" and sometimes means "the surface of a predetermined layer, film, etc., formed on the wafer." The term "substrate" has the same meaning as "wafer" in this specification.

[0063] (Wafer loading)

[0064] Multiple wafers 200 are loaded into wafer cassette 217 (wafer loading), and then, as... Figure 1 As shown, the wafer cassette 217, which supports multiple wafers 200, is lifted by the wafer cassette elevator 115 and moved into the processing chamber 201 (wafer cassette mounting). In this state, the sealing cap 219 is in a state where the lower end of the reaction tube 203 is closed via the O-ring 220.

[0065] (Pressure and temperature adjustments)

[0066] Vacuum pump 246 performs vacuum exhaust, bringing the processing chamber 201 (i.e., the space containing the wafer 200) to the desired pressure (vacuum level). The pressure within the processing chamber 201 is then measured by pressure sensor 245, and the APC valve 243 is controlled based on this pressure information (pressure adjustment). Vacuum pump 246 continues to operate at least until the processing of wafer 200 is complete. Additionally, heater 207 heats the processing chamber 201 to the desired temperature. The power supply to heater 207 is controlled based on temperature information detected by temperature sensor 263, resulting in a desired temperature distribution within the processing chamber 201 (temperature adjustment). Heating of the processing chamber 201 by heater 207 continues at least until the processing of wafer 200 is complete.

[0067] [Deposition process]

[0068] (Supplying TiCl4 gas, 1st step)

[0069] The valve 314 is opened, and TiCl4 gas as a raw material gas flows into the gas supply pipe 310. The TiCl4 gas is adjusted in flow rate by the MFC 312, supplied into the processing chamber 201 from the gas supply holes 410a of the nozzles 410, and exhausted from the exhaust pipe 231. At this time, the TiCl4 gas is supplied to the wafer 200. At the same time, the valve 514 is opened, and a non-reactive gas such as N2 gas flows into the gas supply pipe 510. The N2 gas flowing into the gas supply pipe 510 is adjusted in flow rate by the MFC 512, supplied into the processing chamber 201 together with the TiCl4 gas, and exhausted from the exhaust pipe 231. At this time, in order to prevent the TiCl4 gas from intruding into the nozzles 420, 430, 440, 450, the valves 524, 534, 544, 554 are opened, and N2 gas flows into the gas supply pipes 520, 530, 540, 550. The N2 gas is supplied into the processing chamber 201 via the gas supply pipes 320, 330, 340, 350, the nozzles 420, 430, 440, 450, and exhausted from the exhaust pipe 231.

[0070] At this time, the APC valve 243 is adjusted so that the pressure in the processing chamber 201 is, for example, in the range of 1 to 3990 Pa. The supply flow rate of the TiCl4 gas controlled by the MFC 312 is set to, for example, in the range of 0.1 to 2.0 slm. The supply flow rates of the N2 gas controlled by the MFCs 512, 522, 532, 542, 552 are set to, for example, in the range of 0.1 to 20 slm, respectively. At this time, the temperature of the heater 207 is set to a temperature at which the temperature of the wafer 200 reaches, for example, in the range of 300 to 500°C.

[0071] At this time, the gas flowing in the processing chamber 201 is only the TiCl4 gas and the N2 gas. By supplying the TiCl4 gas, a Ti-containing layer is formed on the wafer 200 (the surface of the base film). The Ti-containing layer can be a Ti layer containing Cl, an adsorption layer of TiCl4, or both.

[0072] (Removal of residual gas, 2nd step)

[0073] After a predetermined time, for example, 0.01 to 10 seconds, after the start of the supply of the TiCl4gas, the valve 314 is closed, and the supply of the TiCl4gas is stopped. At this time, the state of the APC valve 243 that opens the exhaust pipe 231 is maintained, and the inside of the processing chamber 201 is vacuum-exhausted by the vacuum pump 246, and the unreacted or post-TiCl4-gas-contribution-to-Ti-containing-layer-formation TiCl4gas remaining in the processing chamber 201 is exhausted from the processing chamber 201. At this time, the state of the valves 514, 524, 534, 544, and 554 that open is maintained, and the supply of the N2gas into the processing chamber 201 is maintained. The N2gas functions as a purge gas, and the effect of exhausting the unreacted or post-TiCl4-gas-contribution-to-Ti-containing-layer-formation TiCl4gas remaining in the processing chamber 201 from the processing chamber 201 is improved.

[0074] (Supply of NH3gas, 3rd step)

[0075] After the removal of the residual gas in the processing chamber 201, the valve 334 is opened, and the NH3gas as a reaction gas flows in the gas supply pipe 330. The NH3gas is adjusted in flow rate by the MFC 332, and is supplied into the processing chamber 201 from the gas supply hole 430a of the nozzle 430, and is exhausted from the exhaust pipe 231. At this time, the NH3gas is supplied to the wafer 200. At the same time, the valve 534 is opened, and the N2gas flows in the gas supply pipe 530. The N2gas flowing in the gas supply pipe 530 is adjusted in flow rate by the MFC 532. The N2gas is supplied into the processing chamber 201 together with the NH3gas, and is exhausted from the exhaust pipe 231. At this time, in order to prevent the NH3gas from intruding into the nozzles 410, 420, 440, and 450, the valves 514, 524, 544, and 554 are opened, and the N2gas flows in the gas supply pipes 510, 520, 540, and 550. The N2gas is supplied into the processing chamber 201 via the gas supply pipes 310, 320, 340, and 350, the nozzles 410, 420, 440, and 450, and is exhausted from the exhaust pipe 231.

[0076] At this time, the APC valve 243 is adjusted so that the pressure in the processing chamber 201 is, for example, a pressure in the range of 1 to 3990 Pa. The supply flow rate of the NH3gas controlled by the MFC 332 is set to, for example, a flow rate in the range of 0.1 to 30 slm. The supply flow rates of the N2gases controlled by the MFCs 512, 522, 532, 542, and 552 are set to, for example, flow rates in the range of 0.1 to 30 slm, respectively. The time for which the NH3gas is supplied to the wafer 200 is set to, for example, a time in the range of 0.01 to 30 seconds. The temperature of the heater 207 at this time is set to the same temperature as in the step of supplying the TiCl4gas.

[0077] At this time, the gas flowing in the processing chamber 201 is only NH3gas and N2gas. The NH3gas is reacted with at least a part of the Ti-containing layer formed on the wafer 200 by the first step. At the time of the reaction, the Ti contained in the Ti-containing layer combines with the N contained in the NH3gas, and a TiN layer is formed on the wafer 200.

[0078] (Removal of residual gas, fourth step)

[0079] After the TiN layer is formed, the valve 334 is closed, and the supply of the NH3gas is stopped. Then, the unreacted NH3gas remaining in the processing chamber 201 or the NH3gas contributing to the formation of the TiN layer after the reaction, and the reaction byproduct are removed from the processing chamber 201 by the same processing procedure as that described above for the removal of the residual gas.

[0080] (Implementation of a predetermined number of times)

[0081] By repeating the above-mentioned first step to fourth step for a predetermined number of times (n times), a TiN film having a predetermined thickness, for example, a thickness of 1000 A, is formed on the wafer 200.

[0082] [Formation of a crystal layer separation film]

[0083] (Supply of O2gas, fifth-1 step)

[0084] After the TiN film having a predetermined film thickness is formed, the valve 344 is opened, and the O2gas as the oxygen-containing gas is caused to flow in the gas supply pipe 340. The O2gas is adjusted in flow rate by the MFC 342, and is supplied to the processing chamber 201 from the gas supply hole 440a of the nozzle 440, and is exhausted from the exhaust pipe 231. At this time, the O2gas is supplied to the wafer 200. At the same time, the valve 544 is opened, and the N2gas or the like as the non-reactive gas is caused to flow in the gas supply pipe 540. The N2gas flowing in the gas supply pipe 540 is adjusted in flow rate by the MFC 542, and is supplied to the processing chamber 201 together with the O2gas, and is exhausted from the exhaust pipe 231. At this time, the valves 514, 524, 534, and 554 are closed, and the supply of the N2gas from the nozzles 410, 420, 430, and 450 is stopped.

[0085] ​At this time, the APC valve 243 is adjusted so that the pressure in the processing chamber 201 is, for example, a pressure in the range of 0.1 to 3990 Pa, and is set to a different pressure each time this step is performed. Note that the supply flow rate of the O2 gas controlled by the MFC 342 is, for example, set to a flow rate in the range of 0.1 to 10 slm. The supply flow rate of the N2 gas controlled by the MFC 542 is, for example, set to a flow rate in the range of 0.1 to 20 slm. At this time, the temperature of the heater 207 is set so that the temperature of the wafer 200 is constantly maintained at a temperature in the range of, for example, 300 to 500°C, which is the same as the film formation temperature as the temperature at the time of the film formation process. Note that the temperature in this process can also be set to be different from the film formation temperature.

[0086] At this time, the gas flowing in the processing chamber 201 is the O2 gas. By supplying the O2 gas, the TiN film on the wafer 200 (the base film of the surface) is oxidized, oxygen atoms diffuse in the film, and the crystallinity is changed. Thus, a titanium oxynitride (TiNO) film and a titanium oxide (TiO) film, which are crystal layer separation films, are formed on the surface of the TiN film, and the TiN film surface is planarized.

[0087] Note that the pressure at this time can be adjusted to a pressure closer to atmospheric pressure than this pressure. By being closer to atmospheric pressure, the contact probability of the O2 gas molecules with the film to be processed (here, the TiN film) can be increased, and the oxygen adsorption rate on the surface of the film to be processed can be increased. That is, the uniformity of the oxidation process can be increased.

[0088] [Blow-off process]

[0089] (Removal of residual gas, 6th step)

[0090] After a predetermined time has elapsed from the start of the supply of the O2 gas, the valve 344 is closed, and the supply of the O2 gas is stopped. At this time, the state of the APC valve 243, which opens the exhaust pipe 231, is maintained, vacuum exhaust is performed on the processing chamber 201 by the vacuum pump 246, and the O2 gas that has not reacted or that has contributed to the formation of the TiNO film and the TiO film remaining in the processing chamber 201 is exhausted from the processing chamber 201. At this time, the state of the valve 544, which is open, is maintained, the valves 514, 524, 534, and 554 are opened, and the supply of the N2 gas to the processing chamber 201 is started. The N2 gas functions as a blow-off gas, and the effect of exhausting the O2 gas that has not reacted or that has contributed to the formation of the TiNO film and the TiO film remaining in the processing chamber 201 from the processing chamber 201 can be increased.

[0091] [Implementation of a predetermined number of times]

[0092] By performing the film formation process of the predetermined number of times (n times), the crystal layer separation film formation process by supplying O2 gas, and the purging process in a cycle of at least one time (predetermined number of times (m times)), a predetermined film thickness (e.g., ...) can be formed on the wafer 200. TiN film, the predetermined film thickness (e.g.) The TiN film is formed by separating TiNO and TiO films, which act as crystalline layer separators, into films of predetermined thicknesses (e.g., ...). It is obtained by forming TiN films multiple times.

[0093] As described above, the pressure during the O2 gas supply in the crystal layer separator film formation process (step 5-1) is controlled differently for each cycle. Specifically, the pressure during O2 gas supply is controlled such that it increases with each increase in the number of cycles. Furthermore, when forming a target film thickness of... When forming the TiN film, the pressure during the O2 gas supply is controlled to be higher than that during the formation of the film. The pressure during the final O2 gas supply after the TiN film has reached a certain thickness is low. The higher the pressure inside the processing chamber 201, the easier it is for the TiN film surface to be oxidized. Therefore, by controlling the pressure to be lower than the pressure during the final O2 gas supply (e.g., close to atmospheric pressure) and increasing it with each increase in the number of cycles, it is possible to re-oxidize the TiN film surface.

[0094] (Post-purge and atmospheric pressure recovery)

[0095] N2 gas is supplied to the processing chamber 201 through gas supply pipes 510-550, and exhaust gas is discharged through exhaust pipe 231. The N2 gas acts as a purging gas, thereby purging the processing chamber 201 with this inactive gas, removing residual gases and byproducts (post-purging). Then, the atmosphere in the processing chamber 201 is replaced with the inactive gas (inactive gas replacement), and the pressure in the processing chamber 201 is restored to atmospheric pressure (atmospheric pressure restoration).

[0096] (Wafer removal)

[0097] Then, the wafer cassette lifter 115 lowers the sealing cap 219, opening the lower end of the reaction tube 203. Next, the processed wafer 200, supported by the wafer cassette 217, is moved from the lower end of the reaction tube 203 to the outside of the reaction tube 203 (wafer cassette disassembly). Finally, the processed wafer 200 is removed from the wafer cassette 217 (wafer unloading).

[0098] That is, according to this embodiment, whenever a predetermined film thickness (e.g., [missing information]) is formed on wafer 200... ) of the TiN film, the crystal layer separation film formation is performed on the surface of the TiN film. Thereby, the surface of the TiN film is oxidized, the crystallinity is changed, the crystal growth is suppressed, as a result, the formation of abnormal growth nuclei is suppressed, and the TiN film with a predetermined film thickness (for example ) of the planarized TiN film. That is, the W film formed on the surface of the TiN film can be low-resistance.

[0099] (3) Effects according to the present embodiment

[0100] According to the present embodiment, one or more effects shown below can be obtained.

[0101] (a) The formation of abnormal growth nuclei can be suppressed, and the TiN film with planarity can be formed.

[0102] (b) The resistivity of the W film formed on the TiN film can be reduced.

[0103] (4) Other embodiments

[0104] Next, an embodiment other than the above-described embodiment is described in detail. In the following embodiment, only the points different from the above-described embodiment are described in detail.

[0105] (Second embodiment)

[0106] Figure 5 is a diagram showing a film formation flow of the second embodiment.

[0107] The present embodiment differs from the above-described embodiment in the crystal layer separation film formation step. Specifically, using the above-described substrate processing apparatus 10, instead of the supply of the O2 gas in the crystal layer separation film formation step of the above-described embodiment, the supply of the SiH4 gas as a silicon-containing gas is performed.

[0108] [Crystal layer separation film formation step]

[0109] (Supply of SiH4 gas, 5-2 step)

[0110] After the TiN film of a predetermined thickness is formed, the valve 324 is opened, and SiH4gas as a silicon-containing gas is caused to flow in the gas supply pipe 320. The SiH4gas is adjusted in flow rate by the MFC 322, supplied into the processing chamber 201 from the gas supply holes 420a of the nozzle 420, and exhausted from the exhaust pipe 231. At this time, the SiH4gas is supplied to the wafer 200. At the same time, the valve 524 is opened, and a non-reactive gas such as N2gas is caused to flow in the gas supply pipe 520. The N2gas flowing in the gas supply pipe 520 is adjusted in flow rate by the MFC 522, supplied into the processing chamber 201 together with the SiH4gas, and exhausted from the exhaust pipe 231. At this time, the valves 514, 534, 544, and 554 are closed, and the supply of the N2gas from the nozzles 410, 430, 440, and 450 is stopped.

[0111] At this time, the APC valve 243 is adjusted so that the pressure in the processing chamber 201 is, for example, in the range of 0.1 to 3990 Pa. The supply flow rate of the SiH4gas controlled by the MFC 322 is set to, for example, in the range of 0.1 to 10 slm. The supply flow rate of the N2gas controlled by the MFC 522 is set to, for example, in the range of 0.1 to 20 slm. At this time, the temperature of the heater 207 is set so that the temperature of the wafer 200 is constantly maintained at a temperature in the range of, for example, 300 to 500°C, which is the same as the film formation temperature at the time of the film formation process. Note that the temperature in this process can also be set to be different from the film formation temperature.

[0112] At this time, the gas flowing in the processing chamber 201 is the SiH4gas. By supplying the SiH4gas, a titanium silicon nitride (TiSiN) film as a crystal layer separation film is formed on the surface of the TiN film, and the surface of the TiN film is planarized.

[0113] [Blow-off process]

[0114] (Removal of residual gas, 6th step)

[0115] After a predetermined time elapses from the start of the supply of the SiH4gas, the valve 324 is closed, and the supply of the SiH4gas is stopped. At this time, the state of the APC valve 243, which is open, is maintained, and the processing chamber 201 is vacuum-exhausted by the vacuum pump 246, and the unreacted or post-TiSiN film formation SiH4gas remaining in the processing chamber 201 is exhausted from the processing chamber 201. At this time, the state of the valve 524, which is open, is maintained, and the valves 514, 534, 544, and 554 are opened, and the supply of the N2gas into the processing chamber 201 is started. The N2gas functions as a blow-off gas, and can improve the effect of exhausting the unreacted or post-TiSiN film formation SiH4gas remaining in the processing chamber 201 from the processing chamber 201.

[0116] [Carry out the predetermined number of times]

[0117] By carrying out the cycle of the film formation process, the crystal layer separation film formation process by supplying SiH4 gas, and the purge process described above sequentially for the predetermined number of times (n times) one or more times (the predetermined number of times (m times)), a TiN film of a predetermined film thickness (for example, 1000 A) can be formed on the wafer 200. The TiN film of a predetermined film thickness (for example, 1000 A) is formed by separating a TiSiN film, which is a crystal layer separation film, into a plurality of TiN films of a predetermined film thickness (for example, 1000 A). ) of a predetermined film thickness (for example, 1000 A) is formed on the wafer 200, the formation of the crystal layer separation film is carried out on the surface of the TiN film. Thereby, the crystals on the surface of the TiN film can be separated, and the crystal growth of the TiN film is suppressed. As a result, the formation of abnormal growth nuclei is suppressed, and a planarized TiN film of a predetermined film thickness (for example, 1000 A) is formed. That is, the W film formed on the surface of the TiN film can be low-resistance. ) of a predetermined film thickness (for example, 1000 A) is formed on the wafer 200, the formation of the crystal layer separation film is carried out on the surface of the TiN film. Thereby, the crystals on the surface of the TiN film can be separated, and the crystal growth of the TiN film is suppressed. As a result, the formation of abnormal growth nuclei is suppressed, and a planarized TiN film of a predetermined film thickness (for example, 1000 A) is formed. That is, the W film formed on the surface of the TiN film can be low-resistance.

[0118] That is, according to the present embodiment, whenever a TiN film of a predetermined film thickness (for example, 1000 A) is formed on the wafer 200, the formation of the crystal layer separation film is carried out on the surface of the TiN film. Thereby, the crystals on the surface of the TiN film can be separated, and the crystal growth of the TiN film is suppressed. As a result, the formation of abnormal growth nuclei is suppressed, and a planarized TiN film of a predetermined film thickness (for example, 1000 A) is formed. That is, the W film formed on the surface of the TiN film can be low-resistance.

[0119] (Third Embodiment)

[0120] Figure 6 is a film formation flowchart of the third embodiment shown.

[0121] In the present embodiment, instead of the supply of the O2 gas or the supply of the SiH4 gas in the crystal layer separation film formation process of the above-described embodiment, the supply of WF6 gas, which is both a gas containing a metal element and a halogen-containing gas, is carried out in the abnormal growth nucleus removal process.

[0122] [Abnormal growth nucleus removal process]

[0123] (Supply WF6 gas, 5-3 step)

[0124] After the TiN film of a predetermined film thickness is formed, the valve 354 is opened, and WF6 gas, which is a halogen-containing gas, flows into the gas supply pipe 350. The flow rate of the WF6 gas is adjusted by the MFC 352, and the WF6 gas is supplied into the processing chamber 201 from the gas supply hole 450a of the nozzle 450, and is exhausted from the exhaust pipe 231. At this time, the wafer 200 is supplied with the WF6 gas. At the same time, the valve 554 is opened, and a non-reactive gas such as N2 gas flows into the gas supply pipe 550. The flow rate of the N2 gas flowing in the gas supply pipe 550 is adjusted by the MFC 552, and the N2 gas is supplied together with the WF6 gas into the processing chamber 201, and is exhausted from the exhaust pipe 231. At this time, the valves 514, 524, 534, and 544 are closed, and the supply of the N2 gas from the nozzles 410, 420, 430, and 440 is stopped.​​​

[0125] At this time, the APC valve 243 is adjusted so that the pressure in the processing chamber 201 is, for example, a pressure in the range of 0.1 to 6650 Pa. The supply flow rate of the WF6 gas controlled by the MFC 352 is, for example, a flow rate in the range of 0.01 to 10 slm. The supply flow rate of the N2 gas controlled by the MFC 552 is, for example, a flow rate in the range of 0.1 to 30 slm. The time for which the WF6 gas is supplied to the wafer 200 is, for example, a time in the range of 0.01 to 30 seconds. At this time, the temperature of the heater 207 is set so that the temperature of the wafer 200 is constantly maintained at a temperature in the range of, for example, 300 to 500°C, which is the same as the film formation temperature at the time of the film formation process. Note that the temperature in this process can also be set to be different from the film formation temperature.

[0126] At this time, the gas flowing in the processing chamber 201 is the WF6 gas. By supplying the WF6 gas, the abnormal growth nuclei formed on the surface of the TiN film on the wafer 200 are removed (etched), and the TiN film surface is planarized.

[0127] [Blow-off process]

[0128] (Removal of residual gas, 6th step)

[0129] After a predetermined time has elapsed from the start of the supply of the WF6 gas, the valve 354 is closed, and the supply of the WF6 gas is stopped. At this time, the state of the APC valve 243, which is kept open, and the state of the exhaust pipe 231, which is kept open, are maintained, and the inside of the processing chamber 201 is vacuum-exhausted by the vacuum pump 246, and the WF6 gas, which is unreacted or contributes to the removal of the abnormal growth nuclei, and the TiWFx, which is a reaction by-product, and the like, which remain in the processing chamber 201, are exhausted from the processing chamber 201. At this time, the state of the valve 554, which is kept open, is maintained, and the valves 514, 524, 534, and 544 are opened, and the supply of the N2 gas to the processing chamber 201 is started. The N2 gas functions as a blow-off gas, and can improve the effect of exhausting the WF6 gas, which is unreacted or contributes to the removal of the abnormal growth nuclei, and the TiWFx, which is a reaction by-product, and the like, which remain in the processing chamber 201, from the processing chamber 201.

[0130] [Implementation of a predetermined number of times]

[0131] By performing the cycle of the above-described film formation process, abnormal growth nuclei removal process, and blow-off process, which are sequentially performed a predetermined number of times (n times), one time or more (a predetermined number of times (m times)), the abnormal growth nuclei are removed from the wafer 200, and a TiN film having a predetermined film thickness (for example, 1000 A) is formed. The TiN film having a predetermined film thickness (for example, 1000 A) is a TiN film in which an amorphous (non-crystalline) TiN film is divided by a predetermined film thickness (for example, 1000 A). ) is formed. The TiN film having a predetermined film thickness (for example, 1000 A) is a TiN film in which an amorphous (non-crystalline) TiN film is divided by a predetermined film thickness (for example, 1000 A). ) is formed. The TiN film having a predetermined film thickness (for example, 1000 A) is a TiN film in which an amorphous (non-crystalline) TiN film is divided by a predetermined film thickness (for example, 1000 A). TiN film of a predetermined film thickness (e.g., 1000 A) is formed.

[0132] That is, according to the present embodiment, whenever a TiN film of a predetermined film thickness (e.g., 1000 A) is formed on the wafer 200, removal (etching) of abnormal growth nuclei formed on the surface of the TiN film is performed. Thereby, the abnormal growth nuclei generated on the surface of the TiN film are removed, and a planarized TiN film of a predetermined film thickness (e.g., 1000 A) is formed. That is, the W film formed on the surface of the TiN film can be low-resistance.

[0133] (Fourth Embodiment)

[0134] Figure 7 is a view showing a film formation flow of the fourth embodiment.

[0135] In the present embodiment, after the removal process of abnormal growth nuclei of the above-described third embodiment, the above-described crystal layer separation film formation process is performed. That is, both the removal process of abnormal growth nuclei and the crystal layer separation film formation process are performed. Specifically, using the above-described substrate processing apparatus 10, after the supply of the WF6 gas of the removal process of abnormal growth nuclei of the above-described third embodiment is performed, the supply of the O2 gas of the crystal layer separation film formation process of the above-described second embodiment or the supply of the SiH4 gas of the crystal layer separation film formation process of the third embodiment is performed.

[0136] [Performing a predetermined number of times]

[0137] By performing the cycle of the above-described film formation process, the removal process of abnormal growth nuclei, the crystal layer separation film formation process, and the purge process, which are performed a predetermined number of times (n times) in order, one time or more (a predetermined number of times (m times)), a TiN film of a predetermined film thickness (e.g., 1000 A) can be formed on the wafer 200, the TiN film of a predetermined film thickness (e.g., 1000 A) being formed by a plurality of TiN films of a predetermined film thickness (e.g., 1000 A) in which abnormal growth nuclei are removed and separated by a crystal layer separation film.

[0138] That is, according to the present embodiment, whenever a TiN film of a predetermined film thickness (e.g., 1000 A) is formed on the wafer 200, removal of abnormal growth nuclei and formation of a crystal layer separation film are performed. Thereby, after the abnormal growth nuclei generated on the surface of the TiN film are removed, the crystal growth on the surface of the TiN film is suppressed, the formation of abnormal growth nuclei is suppressed, and a planarized TiN film of a predetermined film thickness (e.g., 1000 A) is formed. That is, the W film formed on the surface of the TiN film can be low-resistance.

[0139] (Variation)

[0140] ​​​​​​​Next, using Figure 8 A modification of the film formation step in the film formation process of the present embodiment of the present disclosure will be described.

[0141] The present modification differs from the film formation process of the above-described embodiment in the film formation step. Specifically, in the TiCl4 gas supply in the first step of the film formation step of the above-described embodiment, supply of SiH4 gas is performed.

[0142] [Film formation step]

[0143] (Supply of TiCl4 gas, first step)

[0144] By the same process as the supply of TiCl4 gas in the first step of the film formation step of the above-described embodiment, TiCl4 gas is supplied into the processing chamber 201. At this time, the gas flowing in the processing chamber 201 is only TiCl4 gas and N2 gas, and by the supply of TiCl4 gas, a Ti-containing layer is formed on the wafer 200 (the base film of the surface).

[0145] (Supply of SiH4 gas)

[0146] After a predetermined time, for example, 0.01 to 5 seconds, elapses from the start of the supply of TiCl4 gas, the valve 324 is opened, and SiH4 gas, which is both a reducing gas and a silicon-containing gas, flows into the gas supply pipe 320. The SiH4 gas is adjusted in flow rate by the MFC 322, is supplied into the processing chamber 201 from the gas supply holes 420a of the nozzles 420, and is exhausted from the exhaust pipe 231. At the same time, the valve 524 is opened, and N2 gas or the like, which is an inactive gas, flows into the gas supply pipe 520. The N2 gas flowing in the gas supply pipe 520 is adjusted in flow rate by the MFC 522, is supplied into the processing chamber 201 together with the SiH4 gas, and is exhausted from the exhaust pipe 231. At this time, in order to prevent TiCl4 gas and SiH4 gas from intruding into the nozzles 430, 440, and 450, the valves 534, 544, and 554 are opened, and N2 gas flows into the gas supply pipes 530, 540, and 550. At this time, a state in which TiCl4 gas, SiH4 gas, and N2 gas are simultaneously supplied to the wafer 200 is established. That is, there is at least a point in time at which TiCl4 gas and SiH4 gas are simultaneously supplied.

[0147] At this time, the APC valve 243 is adjusted so that the pressure in the processing chamber 201 is, for example, in the range of 130 to 3990 Pa. If the pressure in the processing chamber 201 is lower than 130 Pa, Si contained in the SiH4 gas enters the Ti-containing layer, and the Si content in the TiN film to be formed increases, possibly resulting in a TiSiN film. If the pressure in the processing chamber 201 is higher than 3990 Pa, similarly, Si contained in the SiH4 gas enters the Ti-containing layer, and the Si content in the TiN film to be formed increases, possibly resulting in a TiSiN film. In this way, regardless of whether the pressure in the processing chamber 201 is too low or too high, the elemental composition of the film being formed changes. The supply flow rate of the SiH4 gas controlled by the MFC 322 is, for example, in the range of 0.1 to 5 slm. The supply flow rates of the N2 gas controlled by the MFCs 512, 522, 532, 542, and 552 are, for example, in the range of 0.01 to 20 slm, respectively. At this time, the temperature of the heater 207 is set to the same temperature as in the step of supplying the TiCl4 gas.

[0148] After a predetermined time, for example, 0.01 to 10 seconds, elapses after the start of the supply of the TiCl4 gas, the valve 314 of the gas supply pipe 310 is closed, and the supply of the TiCl4 gas is stopped. At this time, in order to prevent the SiH4 gas from entering the nozzle 410, the state in which the valve 514 is open is maintained, and the N2 gas flows in the gas supply pipes 510, 530, 540, and 550. The N2 gas is supplied to the processing chamber 201 via the gas supply pipes 310, 330, 340, and 350, the nozzles 410, 430, 440, and 450, and is exhausted from the exhaust pipe 231. At this time, the state in which the SiH4 gas and the N2 gas are supplied to the wafer 200 is established.

[0149] (Removal of residual gas, second step)

[0150] After a predetermined time, for example, 0.01 to 60 seconds, has passed from the start of the supply of the SiH4gas, the valve 324 is closed, and the supply of the SiH4gas is stopped. At this time, the state of the APC valve 243 that opens the exhaust pipe 231 is maintained, the inside of the processing chamber 201 is vacuum-exhausted by the vacuum pump 246, and the unreacted or post-TiN-layer-formation contributing TiCl4gas and SiH4gas remaining in the processing chamber 201 are exhausted from the processing chamber 201. At this time, the state of the valves 514, 524, 534, 544, and 554 that open is maintained, and the supply of the N2gas into the processing chamber 201 is maintained. The N2gas functions as a purge gas, and the effect of exhausting the unreacted or post-TiN-layer-formation contributing TiCl4gas and SiH4gas remaining in the processing chamber 201 from the processing chamber 201 is improved. Here, the HCl that is a growth hindering factor reacts with the SiH4, forms silicon tetrachloride (SiCl4) and H2, and is exhausted from the processing chamber 201.

[0151] (Supply of NH3gas, 3rd step)

[0152] After the residual gas in the processing chamber 201 is removed, the NH3gas is supplied into the processing chamber 201 by the same processing procedure as the 3rd step of the film formation process of the above embodiment.

[0153] (Removal of residual gas, 4th step)

[0154] After a predetermined time has passed from the start of the supply of the NH3gas, the valve 334 is closed, and the supply of the NH3gas is stopped. At this time, the state of the APC valve 243 that opens the exhaust pipe 231 is maintained, the inside of the processing chamber 201 is vacuum-exhausted by the vacuum pump 246, and the unreacted or post-TiN-layer-formation contributing NH3gas and reaction byproduct remaining in the processing chamber 201 are exhausted from the processing chamber 201 by the same processing procedure as the 4th step of the film formation process of the above embodiment.

[0155] (Implementation of a predetermined number of times)

[0156] By performing the above 1st to 4th steps in a cycle for a predetermined number of times (n times), a TiN film of a predetermined thickness (for example, 1000 A in thickness) is formed on the wafer 200.

[0157] Further, in the present modified example, by performing either or both of the crystal layer separation film formation process and the abnormal growth nucleus removal process, the same effects as the film formation flow shown in Fig. 6 can be obtained. Figures 4-7

[0158] ​​Note that, in the above embodiment, the formation process of the TiN film is exemplified, but the present disclosure is also applicable to metal films other than the TiN film. For example, as the metal element, there are W, Ta, Ru, Mo, Zr, Hf, Al, Si, Ge, Ga, or the like, or elements of the same group as these elements, transition metals. It is also applicable to films of these elements alone, compound films of these metals and nitrogen (nitride films), compound films of these metals and oxygen (oxide films), and the like. Note that, in forming these films, the above halogen-containing gas, a gas containing at least any one of a halogen element, an amino group, a cyclopentyl group, and oxygen (O) can be used.

[0159] Note that, in the above embodiment, the case where O2 gas is used as the oxygen-containing gas used in the crystal layer separation film formation process is exemplified, but the present disclosure is not limited to this, and is also applicable when O3 gas, NO gas, N2O gas, or the like is used as the oxygen-containing gas. In addition, in the crystal layer separation film formation process using the oxygen-containing gas, since it is necessary to diffuse oxygen atoms in the TiN film, it is preferable to use O2 gas, O3 gas, NO gas, N2O gas, or the like as the oxygen-containing gas, rather than water vapor (H2O) containing hydrogen atoms.

[0160] Note that, in the above embodiment, the oxidation treatment using the oxygen-containing gas is exemplified as the process of the crystal layer separation film formation process, but the present disclosure is not limited to this. For example, by performing nitriding treatment using a nitrogen-containing gas, the crystal can also be separated. As the nitrogen-containing gas, for example, there are ammonia (NH3) gas, nitrogen (N2) gas, hydrogen (H2) gas, and the like. In addition, it can also be an active species of these gases.

[0161] In addition, in the above embodiment, the case where SiH4 gas is used as the silicon-containing gas used in the crystal layer separation film formation process is exemplified, but the present disclosure is not limited to this, and is also applicable when silane-based gas or chlorosilane-based gas such as hexachlorodisilane (Si2Cl6) gas is used.

[0162] In addition, in the above embodiment, the case where WF6 gas, which is a gas containing a halogen element and a metal element, is used as the halogen-containing gas used in the abnormal growth nucleus removal process is exemplified, but the present disclosure is not limited to this, and is also applicable when a halogen-containing gas not containing a metal element is used. As the halogen-containing gas not containing a metal element, for example, there are NF3 gas, ClF3 gas, F2 gas, HF gas, and the like. Note that the halogen element is Cl, F, Br, or the like, and the metal element is W, Ti, Ta, Mo, Zr, Hf, Al, Si, Ge, Ga, or the like. It is applicable to a gas containing these elements. Note that it can also be a gas in which the halogen-containing gas further contains oxygen (O) element. For example, it is MoO2Cl2, MoOCl4, or the like.

[0163] In addition, in the above-described embodiments, an example in which the film is formed using a batch-type vertical apparatus that processes a plurality of substrates at a time has been described, but the present disclosure is not limited to this, and is also favorably applicable when the film is formed using a single-wafer substrate processing apparatus that processes one or a few substrates at a time.

[0164] For example, the present disclosure is also favorably applicable when the film is formed using a substrate processing apparatus having a processing furnace 302 as shown in (A) of FIG. 10. Figure 9 The processing furnace 302 has a processing container 303 that forms a processing chamber 301, a shower head 303s that supplies a gas into the processing chamber 301 in a shower shape, a support table 317 that supports one or a plurality of wafers 200 in a horizontal attitude, a rotary shaft 355 that supports the support table 317 from below, and a heater 307 provided in the support table 317. An inlet (gas introduction port) of the shower head 303s is connected to a gas supply interface 332a that supplies the above-described source gas, a gas supply interface 332b that supplies the above-described reaction gas, and a gas supply interface 332c that supplies an oxygen-containing gas, a silicon-containing gas, or a halogen-containing gas. The gas supply interface 332a is connected to a source gas supply system similar to that of the above-described embodiments. The gas supply interface 332b is connected to a reaction gas supply system similar to that of the above-described embodiments. The gas supply interface 332c is connected to a gas supply system similar to that of the above-described oxygen-containing gas, silicon-containing gas, or halogen-containing gas supply system. A gas dispersion plate that supplies a gas into the processing chamber 301 in a shower shape is provided at an outlet (gas exhaust port) of the shower head 303s. An exhaust interface 331 that exhausts the processing chamber 301 is provided in the processing container 303. The exhaust interface 331 is connected to an exhaust system similar to that of the above-described embodiments.

[0165] For example, the present disclosure is also favorably applicable when the film is formed using a substrate processing apparatus having a processing furnace 302 as shown in (A) of FIG. 10. Figure 9The present disclosure is also applicable when a film is formed by a substrate processing apparatus of a processing furnace 402 shown in (B). The processing furnace 402 has a processing container 403 forming a processing chamber 401, a support table 417 supporting one or a plurality of wafers 200 in a horizontal attitude, a rotary shaft 455 supporting the support table 417 from below, a lamp heater 407 irradiating light to the wafer 200 toward the processing container 403, and a quartz window 403w transmitting the light of the lamp heater 407. The processing container 403 is connected to a gas supply interface 432a supplying the above-mentioned source gas, a gas supply interface 432b supplying the above-mentioned reaction gas, and a gas supply interface 432c supplying the above-mentioned oxygen-containing gas, silicon-containing gas, or halogen-containing gas. The gas supply interface 432a is connected to a source gas supply system similar to that of the above-mentioned embodiment. The gas supply interface 432b is connected to a reaction gas supply system similar to that of the above-mentioned embodiment. The gas supply interface 432c is connected to a gas supply system similar to that of the above-mentioned embodiment. The processing container 403 is provided with an exhaust interface 431 for exhausting the processing chamber 401. The exhaust interface 431 is connected to an exhaust system similar to that of the above-mentioned embodiment.

[0166] When these substrate processing apparatuses are used, film formation can be performed by the same procedures and processing conditions as those of the above-mentioned embodiment.

[0167] The process recipe (a program describing a processing procedure, a processing condition, and the like) used in the formation of these various films is preferably prepared (prepared plural) individually according to the content of the substrate processing (the film type, the composition ratio, the film quality, the film thickness, the processing procedure, the processing condition, and the like of the film to be formed). Further, it is preferable that, at the start of the substrate processing, an appropriate process recipe is appropriately selected from among the plural process recipes according to the content of the substrate processing. Specifically, it is preferable that the plural process recipes prepared individually according to the content of the substrate processing are stored (installed) in advance in a storage device 121c possessed by the substrate processing apparatus via a communication circuit, a recording medium (an external storage device 123) recording the process recipe. Further, it is preferable that, at the start of the substrate processing, a CPU 121a possessed by the substrate processing apparatus appropriately selects an appropriate process recipe from among the plural process recipes stored in the storage device 121c according to the content of the substrate processing. With such a configuration, various film types, composition ratios, film qualities, and film thicknesses of films can be formed commonly and with good reproducibility by one substrate processing apparatus. In addition, it is possible to reduce the operation burden (the burden of inputting a processing procedure, a processing condition, and the like) of an operator, to prevent operation mistakes, and to quickly start the substrate processing.

[0168] Furthermore, this disclosure can be implemented, for example, by changing the process formulation of an existing substrate processing apparatus. When changing the process formulation, the process formulation involved in this disclosure can also be installed in an existing substrate processing apparatus via a communication circuit or a recording medium recording the process formulation, or the input / output device of an existing substrate processing apparatus can be operated to change its process formulation to the process formulation of this disclosure.

[0169] In addition, this disclosure can be used, for example, for word line portions of NAND flash memory, DRAM, etc., which have a 3D structure.

[0170] The above describes various typical embodiments of this disclosure, but this disclosure is not limited to these embodiments and can be applied in appropriate combinations.

[0171] (4) Examples

[0172] Figure 10 Comparative examples show that the substrate processing apparatus 10 described above is used to process the above... Figure 4 The film deposition process is formed on wafer 200. The cross-section of a wafer when a TiN film of a certain thickness is applied. Figure 10 Example 1 shows the use of the above-described substrate processing apparatus 10 to process the above-described... Figure 4 Film formation process (per film formation) A TiN film of a certain thickness is formed on a wafer 200 by supplying O2 gas. The cross-section of the wafer when the TiN film is applied. Figure 10 Example 2 shows the use of the above-described substrate processing apparatus 10 to process the above-described... Figure 5 Film formation process (per film formation) A TiN film of a certain thickness is formed on a wafer by supplying SiH4 gas. The cross-section of the wafer when the TiN film is applied. Figure 10 Example 3 shows the use of the above-described substrate processing apparatus 10 to process the above-described... Figure 6 Film formation process (per film formation) A TiN film of a certain thickness is formed on a wafer by supplying WF6 gas. The cross-section of the wafer when the TiN film is applied.

[0173] Furthermore, the cross-sections of the TiN films formed in the comparative examples and Examples 1-3 were observed using atomic force microscopy. Figure 10As shown, abnormal growth nuclei were confirmed on the surface of the TiN film of the comparative example. The root mean square roughness (Rms) of the TiN film of the comparative example was 1.62 nm, and the maximum height difference (Rmax) was 25.7 nm. On the other hand, the surface of the TiN film of Example 1 was confirmed to be planarized. It was confirmed that the TiN film was layered with three layers of TiN films, and a crystal separation film was formed between the TiN films, respectively. The root mean square roughness (Rms) of the TiN film of Example 1 was 0.91 nm, and the maximum height difference (Rmax) was 9.79 nm. In addition, the surface of the TiN film of Example 2 was confirmed to be planarized. It was confirmed that the TiN film was layered with three layers of TiN films, and a crystal separation film was formed between the TiN films, respectively. The root mean square roughness (Rms) of the TiN film of Example 2 was 0.80 nm, and the maximum height difference (Rmax) was 9.56 nm. In addition, the surface of the TiN film of Example 3 was confirmed to be planarized. It was confirmed that the TiN film was layered with three layers of TiN films separated by an amorphous (non-crystalline) TiN film. The root mean square roughness (Rms) of the TiN film of Example 3 was 1.00 nm, and the maximum height difference (Rmax) was 11.3 nm.

[0174] That is, it was confirmed that when the film formation process of the TiN film on the wafer 200 was performed to form a TiN film having a thickness of 100 nm or more, either one or both of the formation process of the crystal layer separation film and the removal process of the abnormal growth nuclei on the wafer 200 were performed, and thus a TiN film having a thickness of 100 nm or more and having planarity could be formed.

[0175] Symbol explanation

[0176] 10: substrate processing apparatus, 121: controller, 200: wafer (substrate), 201: processing chamber.​​

Claims

1. A substrate processing method comprising the following steps: (a1) A process of supplying a gas containing metallic and halogen elements to a substrate. (a2) During the process of supplying silicon-containing gas to the substrate in (a1), (a3) The process of supplying reactive gas to the substrate, (a4) A process of forming a metal-containing film containing the metal element on the substrate by performing (a1), (a2), and (a3) ​​a predetermined number of times. (b) A process step in which a processing gas is supplied instead of the reactant gas to the substrate, and a crystal layer separating film is formed on the surface of the metal film. (c) A process of forming multiple layers of the metal-containing film on the substrate by performing (a4) and (b) a predetermined number of times.

2. The method according to claim 1, wherein, In (b), the pressure of the space in the substrate is different during each cycle when the processing gas is supplied.

3. The method according to claim 2, wherein, In (b), the pressure in the space where the substrate exists during the supply of the processing gas increases with each increase in the number of cycles.

4. The method according to claim 1, wherein, In (b), both the formation process of the crystal layer separating film and the removal process of abnormal growth nuclei are performed.

5. The method according to claim 4, wherein, In (b), after the process of removing the abnormal growth nuclei, the process of forming the crystal layer separation film is carried out.

6. The method according to claim 4, wherein, In (b), the process of removing the abnormal growth nuclei and forming the crystal layer separation film are performed repeatedly.

7. The method according to claim 1, wherein, In the process of forming the crystal layer separator film, oxygen-containing gas is supplied as the processing gas.

8. The method according to claim 7, wherein, The oxygen-containing gas is oxygen, ozone, nitric oxide, or nitrous oxide.

9. The method according to claim 1, wherein, In the process of forming the crystal layer separator film, silicon-containing gas is supplied as the processing gas.

10. The method according to claim 9, wherein, The silicon-containing gas is a silane-based gas.

11. The method according to claim 9, wherein, The silicon-containing gas is a chlorosilane-based gas.

12. The method according to claim 4, wherein, In the process of removing the abnormal growth nuclei, a halogen-containing gas is supplied as the processing gas.

13. The method according to claim 12, wherein, The halogen-containing gas is at least one of nitrogen trifluoride, tungsten hexafluoride, chlorine trifluoride, fluorine, and hydrogen fluoride.

14. A method for manufacturing a semiconductor device, comprising the following steps: (a1) A process of supplying a gas containing metallic and halogen elements to a substrate. (a2) During the process of supplying silicon-containing gas to the substrate in (a1), (a3) The process of supplying reactive gas to the substrate, (a4) A process of forming a metal-containing film containing the metal element on the substrate by performing (a1), (a2), and (a3) ​​a predetermined number of times. (b) A process step in which a processing gas is supplied instead of the reactant gas to the substrate, and a crystal layer separating film is formed on the surface of the metal film. (c) A process of forming multiple layers of the metal-containing film on the substrate by performing (a4) and (b) a predetermined number of times.

15. A computer-readable recording medium having a program that causes a substrate processing apparatus to perform the following processes via a computer. (a1) The process of supplying a gas containing metallic and halogen elements to a substrate. (a2) The process of supplying silicon-containing gas to the substrate during (a1), (a3) The process of supplying reactive gas to the substrate, (a4) A process of forming a metal-containing film containing the metal element on the substrate by performing (a1), (a2), and (a3) ​​a predetermined number of times. (b) The process of forming a crystalline separation film on the surface of the metal-containing film by supplying a processing gas instead of the reactant gas to the substrate. (c) The process of forming multiple layers of the metal-containing film on the substrate by performing (a4) and (b) a predetermined number of times.

16. A substrate processing apparatus comprising: A gas supply system for supplying gases containing metallic and halogen elements, silicon-containing gases, reactive gases, and processing gases to a substrate, and The control unit is configured to perform the following processes by controlling the gas supply system: (a1) A process of supplying the substrate with a gas containing the metal element and the halogen element. (a2) During (a1), the substrate is supplied with the silicon-containing gas. (a3) The process of supplying the reactant gas to the substrate, (a4) A process of forming a metal-containing film containing the metal element on the substrate by performing (a1), (a2), and (a3) ​​a predetermined number of times. (b) A process gas is supplied instead of the reactant gas to form a crystalline separation film on the surface of the metal-containing film. (c) Performing (a4) and (b) a predetermined number of times to form a multilayer of the metal-containing film on the substrate.

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