Substrate processing method, program, substrate processing device, and manufacturing method for semiconductor device

Abstract

To provide a technique capable of improving the film characteristics.SOLUTION: A manufacturing method includes the steps of: (a) preparing a substrate having a film containing titanium, molybdenum, ruthenium, or copper as a first metal element, and a film formed on the film containing the first metal element and containing boron, aluminum, gallium, or indium as a group 13 element or silicon or germanium as a group 14 element; (b) supplying a gas containing tungsten as a second metal element and halogen to the substrate; (c) supplying a first reaction gas to the substrate; and (d) forming a film containing the second metal element by removing at least a part of the film containing the group 13 element or the group 14 element by performing (b) and (c).SELECTED DRAWING: Figure 7

Description

[Technical field]

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

[0002] In recent years, with the increasing integration and performance of semiconductor devices, various kinds of metal films are used to manufacture semiconductor devices with three-dimensional structures. A tungsten film (W film) or the like is used for the control gate of a NAND-type flash memory, which is an example of a semiconductor device with a three-dimensional structure. In addition, for example, a titanium nitride (TiN) film may be used as a barrier film between the W film and the insulating film (see, for example, Patent Document 1 and Patent Document 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-69407 A [Patent Document 2] JP 2018-49898 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, when another metal film, such as a W film, is formed on the surface of a metal film, such as a TiN film, the surface of the metal film may be etched by the deposition gas used to form the other metal film, and the etching of the surface of the metal film may result in a deterioration of the film properties.

[0005] An object of the present disclosure is to provide a technique capable of improving film properties. [Means for solving the problem]

[0006] According to one aspect of the present disclosure, (a) preparing a substrate having a film containing titanium, molybdenum, ruthenium, or copper as a first metal element, and a film containing boron, aluminum, gallium, or indium as a Group 13 element, or silicon or germanium as a Group 14 element, formed on the film containing the first metal element; (b) supplying a gas containing tungsten as a second metal element and a halogen to the substrate; (c) supplying a first reactive gas to the substrate; having (d) performing (b) and (c) to remove at least a portion of the film containing the Group 13 element or the Group 14 element, thereby forming a film containing the second metal element; The present invention provides a technique having the following features: Effect of the Invention

[0007] According to the present disclosure, film characteristics can be improved. [Brief description of the drawings]

[0008] [Figure 1] 2 is a vertical cross-sectional view illustrating a configuration of a processing furnace 202a of the substrate processing apparatus 10 according to an embodiment of the present disclosure. [Diagram 2] 2 is a cross-sectional view taken along line AA of the processing furnace 202a shown in FIG. [Diagram 3] 1 is a vertical cross-sectional view illustrating a configuration of a processing furnace 202b of the substrate processing apparatus 10 according to an embodiment of the present disclosure. [Figure 4] 4 is a cross-sectional view of the process furnace 202b shown in FIG. 3 taken along the line AA. [Diagram 5] FIG. 2 is a block diagram for illustrating a configuration of a control unit of the substrate processing apparatus 10 according to an embodiment of the present disclosure. [Figure 6] 2A to 2C are diagrams showing a substrate processing sequence in a processing furnace 202a of the substrate processing apparatus 10 according to an embodiment of the present disclosure. [Figure 7]1A to 1C are diagrams illustrating a substrate processing sequence in a processing furnace 202b of the substrate processing apparatus 10 according to an embodiment of the present disclosure. [Figure 8] 8(A) and 8(B) are diagrams for explaining a film formed on a substrate by processing in the processing furnace 202a, and FIG. 8(C) is a diagram for explaining a film formed on a substrate by processing in the processing furnace 202b. [Figure 9] 11 is a diagram showing a modified example of a substrate processing sequence in a processing furnace 202b of the substrate processing apparatus 10 according to an embodiment of the present disclosure. [Figure 10] FIG. 10(A) is a diagram showing the structures of Sample 1 and Sample 2 used in this example, and FIGS. 10(B) and 10(C) are diagrams showing the results of XPS analysis of Sample 1 and Sample 2 shown in FIG. 10(A). [Figure 11] FIG. 11(A) is a diagram showing the structures of Sample 1 and Sample 2 used in this example, and FIGS. 11(B) and 11(C) are diagrams showing the results of XPS analysis of Sample 1 and Sample 2 shown in FIG. 11(A). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] <One embodiment of the present disclosure> Hereinafter, an embodiment of the present disclosure will be described with reference to FIGS. 1 to 7 and 8(A) to 8(C). A substrate processing apparatus 10 is configured as an example of an apparatus used in a manufacturing process of a semiconductor device. It should be noted that all of the drawings used in the following description are schematic, and the dimensional relationships of the elements, the ratios of the elements, and the like shown in the drawings do not necessarily match the actual ones. Furthermore, the dimensional relationships of the elements, the ratios of the elements, and the like between multiple drawings do not necessarily match.

[0010] (1) Configuration of the substrate processing device FIG. 1 is a vertical cross-sectional view of a processing furnace 202a serving as a first process unit provided in a substrate processing apparatus (hereinafter simply referred to as a substrate processing apparatus 10) capable of carrying out a manufacturing method for a semiconductor device, and FIG. 2 is a cross-sectional view of the processing furnace 202a taken along line AA. In this embodiment, an example will be described in which a first metal-containing film is formed on a wafer 200 in a processing furnace 202a serving as a first process unit, and a cap film is formed on the first metal-containing film, and then a second metal-containing film is formed in a processing furnace 202b serving as a second process unit described later, while removing at least a portion of the cap film formed on the first metal-containing film.

[0011] The processing furnace 202a includes a heater 207 as a heating means (heating mechanism, heating system, heating unit). The heater 207 has a cylindrical shape and is installed vertically by being supported by a heater base (not shown) as a holding plate.

[0012] An outer tube 203 constituting a reaction vessel (processing vessel) is disposed inside the heater 207 concentrically with the heater 207. The outer tube 203 is made of a heat-resistant material such as quartz (SiO2) or silicon carbide (SiC) and is formed in a cylindrical shape with a closed upper end and an open lower end. A manifold (inlet flange) 209 is disposed below the outer tube 203 concentrically with the outer tube 203. The manifold 209 is made of a metal such as stainless steel (SUS) and is formed in a cylindrical shape with open upper and lower ends. An O-ring 220a is provided between the upper end of the manifold 209 and the outer tube 203 as a seal member. The manifold 209 is supported by a heater base, so that the outer tube 203 is installed vertically.

[0013] An inner tube 204 constituting a reaction vessel is disposed inside the outer tube 203. The inner tube 204 is made of a heat-resistant material such as quartz (SiO2) or silicon carbide (SiC) and is formed in a cylindrical shape with a closed upper end and an open lower end. A processing vessel (reaction vessel) is mainly constituted by the outer tube 203, the inner tube 204, and the manifold 209. A processing chamber 201a is formed in a cylindrical hollow portion (inside the inner tube 204) of the processing vessel. Note that, although the inner tube 204 is included in the configuration of the processing vessel (reaction vessel) and the processing chamber 201a here, the inner tube 204 may be omitted.

[0014] The processing chamber 201a is configured to be capable of accommodating wafers 200 as substrates in a boat 217 (described later) in a horizontal position and in a state of being arranged in multiple stages in the vertical direction.

[0015] In the processing chamber 201a, nozzles 410, 420, 430 are provided so as to penetrate the sidewall of the manifold 209 and the inner tube 204. The nozzles 410, 420, 430 are connected to gas supply pipes 310, 320, 330 as gas supply lines, respectively. In this manner, the substrate processing apparatus 10 is provided with three nozzles 410, 420, 430 and three gas supply pipes 310, 320, 330, and is configured to be able to supply a plurality of types of gases into the processing chamber 201a. However, the processing furnace 202a of this embodiment is not limited to the above-mentioned form.

[0016] Gas supply pipes 310, 320, 330 are respectively provided with mass flow controllers (MFCs) 312, 322, 332, which are flow rate control devices (flow rate control parts), in order from the upstream side. Also, gas supply pipes 310, 320, 330 are respectively provided with valves 314, 324, 334, which are on-off valves. Gas supply pipes 510, 520, 530, which supply inert gas, are connected to the downstream sides of valves 314, 324, 334 of gas supply pipes 310, 320, 330, respectively. Gas supply pipes 510, 520, 530 are respectively provided with MFCs 512, 522, 532 and valves 514, 524, 534, in order from the upstream side.

[0017] Nozzles 410, 420, 430 are respectively connected to the tips of the gas supply pipes 310, 320, 330. The nozzles 410, 420, 430 are configured as L-shaped nozzles, and their horizontal parts are provided so as to penetrate the side wall of the manifold 209 and the inner tube 204. The vertical parts of the nozzles 410, 420, 430 are provided inside the channel-shaped (groove-shaped) preliminary chamber 205a formed so as to protrude radially outward from the inner tube 204 and extend vertically, and are provided in the preliminary chamber 205a facing upward (upward in the arrangement direction of the wafers 200) along the inner wall of the inner tube 204.

[0018] The nozzles 410, 420, 430 are provided so as to extend from the lower region of the processing chamber 201a to the upper region of the processing chamber 201a, and a plurality of gas supply holes 410a, 420a, 430a are provided at positions facing the wafer 200. As a result, the gas supply holes 410a, 420a, 430a of the nozzles 410, 420, 430 supply processing gas to the wafer 200. The gas supply holes 410a, 420a, 430a are provided from the lower part to the upper part of the inner tube 204, each having the same opening area, and further provided at the same opening pitch. However, the gas supply holes 410a, 420a, 430a are not limited to the above-mentioned form. For example, the opening area may be gradually increased from the lower part to the upper part of the inner tube 204. As a result, the flow rate of the gas supplied from the gas supply holes 410a, 420a, 430a can be made more uniform.

[0019] The gas supply holes 410a, 420a, 430a of the nozzles 410, 420, 430 are provided at a height from the bottom to the top of the boat 217 described later. Therefore, the process gas supplied from the gas supply holes 410a, 420a, 430a of the nozzles 410, 420, 430 into the process chamber 201a is supplied to the wafers 200 accommodated from the bottom to the top of the boat 217, i.e., to the entire area of ​​the wafers 200 accommodated in the boat 217. The nozzles 410, 420, 430 may be provided so as to extend from the bottom area to the top area of ​​the process chamber 201a, but are preferably provided so as to extend to the vicinity of the ceiling of the boat 217.

[0020] From the gas supply pipe 310, a gas containing a first metal element (hereinafter also referred to as a "first metal-containing gas") is supplied as a processing gas into the processing chamber 201a via the MFC 312, the valve 314, and the nozzle 410.

[0021] From the gas supply pipe 320, a third reactive gas that reacts with the first metal-containing gas is supplied as a processing gas into the processing chamber 201a via the MFC 322, the valve 324, and the nozzle 420. Note that in this disclosure, an example will be described in which the third reactive gas is also used as a reactive gas that reacts with a Group 13 element or Group 14 element-containing gas, which will be described later.

[0022] From the gas supply pipe 330, a gas containing a Group 13 element or a Group 14 element is supplied as a process gas through the MFC 332, the valve 334, and the nozzle 430 into the process chamber 201a.

[0023] From the gas supply pipes 510, 520, and 530, an inert gas such as nitrogen (N2) gas is supplied into the processing chamber 201a via the MFCs 512, 522, and 532, the valves 514, 524, and 534, and the nozzles 410, 420, and 430. An example in which N2 gas is used as the inert gas will be described below, but as the inert gas, other than N2 gas, for example, a rare gas such as argon (Ar) gas, helium (He) gas, neon (Ne) gas, or xenon (Xe) gas may be used.

[0024] The process gas supply system is mainly composed of the gas supply pipes 310, 320, 330, the MFCs 312, 322, 332, the valves 314, 324, 334, and the nozzles 410, 420, 430, but only the nozzles 410, 420, 430 may be considered as the process gas supply system. The process gas supply system may be simply called a gas supply system. When the first metal-containing gas is caused to flow from the gas supply pipe 310, the first metal-containing gas supply system is mainly composed of the gas supply pipe 310, the MFCs 312, and the valve 314, but the nozzles 410 may be considered to be included in the first metal-containing gas supply system. When the third reactive gas is caused to flow from the gas supply pipe 320, the third reactive gas supply system is mainly composed of the gas supply pipe 320, the MFCs 322, and the valve 324, but the nozzles 420 may be considered to be included in the third reactive gas supply system. When a nitrogen-containing gas is supplied as the third reactive gas from the gas supply pipe 320, the third reactive gas supply system can also be called a nitrogen-containing gas supply system. When a Group 13 element or Group 14 element-containing gas is flowed from the gas supply pipe 330, the Group 13 element or Group 14 element-containing gas supply system is mainly composed of the gas supply pipe 330, the MFC 332, and the valve 334, but the nozzle 430 may be included in the Group 13 element or Group 14 element-containing gas supply system. An inert gas supply system is mainly composed of the gas supply pipes 510, 520, and 530, the MFCs 512, 522, and 532, and the valves 514, 524, and 534.

[0025] In the method of supplying gas in this embodiment, gas is transported through nozzles 410, 420, and 430 arranged in a vertically elongated circular space defined by the inner wall of the inner tube 204 and the ends of the multiple wafers 200, i.e., in a cylindrical space, the preliminary chamber 205a. Then, gas is ejected into the inner tube 204 from multiple gas supply holes 410a, 420a, and 430a provided in positions of the nozzles 410, 420, and 430 facing the wafer. More specifically, the gas supply hole 410a of the nozzle 410, the gas supply hole 420a of the nozzle 420, and the gas supply hole 430a of the nozzle 430 eject the processing gas or the like in a direction parallel to the surface of the wafer 200, i.e., in a horizontal direction.

[0026] The exhaust hole (exhaust port) 204a is a through hole formed in a side wall of the inner tube 204 at a position facing the nozzles 410, 420, 430, i.e., at a position 180 degrees opposite to the preliminary chamber 205a, and is, for example, a slit-shaped through hole that is elongated in the vertical direction. Therefore, gas that is supplied from the gas supply holes 410a, 420a, 430a of the nozzles 410, 420, 430 into the processing chamber 201a and flows over the surface of the wafer 200, i.e., the remaining gas (residual gas), flows into the exhaust path 206 formed by the gap formed between the inner tube 204 and the outer tube 203 through the exhaust hole 204a. The gas that flows into the exhaust path 206 flows into the exhaust pipe 231 and is discharged outside the processing furnace 202a.

[0027] The exhaust hole 204a is provided at a position facing the multiple wafers 200 (preferably at a position facing the upper to lower parts of the boat 217), and the gas supplied from the gas supply holes 410a, 420a, 430a to the vicinity of the wafers 200 in the processing chamber 201a flows in a horizontal direction, i.e., in a direction parallel to the surface of the wafer 200, and then flows into the exhaust path 206 through the exhaust hole 204a. That is, the gas remaining in the processing chamber 201a is exhausted parallel to the main surface of the wafer 200 through the exhaust hole 204a. Note that the exhaust hole 204a is not limited to being configured as a slit-shaped through hole, and may be configured as a plurality of holes.

[0028] The manifold 209 is provided with an exhaust pipe 231 for exhausting the atmosphere in the processing chamber 201a. The exhaust pipe 231 is connected to a pressure sensor 245 as a pressure detector (pressure detection unit) for detecting the pressure in the processing chamber 201a, an APC (Auto Pressure Controller) valve 243, and a vacuum pump 246 as a vacuum exhaust device, in this order from the upstream side. The APC valve 243 can evacuate and stop the evacuation of the processing chamber 201a by opening and closing the valve while the vacuum pump 246 is operating, and further, the pressure in the processing chamber 201a can be adjusted by adjusting the valve opening while the vacuum pump 246 is operating. An exhaust system, i.e., an exhaust line, is mainly configured by the exhaust hole 204a, the exhaust path 206, the exhaust pipe 231, the APC valve 243, and the pressure sensor 245. The vacuum pump 246 may be included in the exhaust system.

[0029] Below the manifold 209, a seal cap 219 is provided as a furnace port cover capable of airtightly closing the lower end opening of the manifold 209. The seal cap 219 is configured to abut against the lower end of the manifold 209 from below in the vertical direction. The seal cap 219 is made of a metal such as SUS and is formed in a disk shape. An O-ring 220b is provided on the upper surface of the seal cap 219 as a seal member that abuts against the lower end of the manifold 209. On the opposite side of the seal cap 219 to the processing chamber 201a, a rotation mechanism 267 is installed to rotate the boat 217 that accommodates the wafers 200. A rotation shaft 255 of the rotation mechanism 267 is connected to the boat 217 through the seal cap 219. The rotation mechanism 267 is configured to rotate the wafers 200 by rotating the boat 217. The seal cap 219 is configured to be raised and lowered in the vertical direction by a boat elevator 115 as a lifting mechanism that is vertically installed outside the outer tube 203. The boat elevator 115 is configured to be able to load and unload the boat 217 into and out of the processing chamber 201a by raising and lowering the seal cap 219. The boat elevator 115 is configured as a transfer device (transfer mechanism) that transfers the boat 217 and the wafers 200 accommodated in the boat 217 into and out of the processing chamber 201a.

[0030] The boat 217 as a substrate support is configured to support a plurality of wafers 200, for example 25 to 200, in a horizontal position and aligned vertically with their centers aligned, i.e., arranged at intervals. 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 made of a heat-resistant material such as quartz or SiC are supported in multiple stages (not shown) in a horizontal position. This configuration makes it difficult for heat from the heater 207 to be transmitted to the seal cap 219. However, this embodiment is not limited to the above-mentioned form. For example, instead of providing the heat insulating plate 218 at the bottom of the boat 217, a heat insulating cylinder configured as a cylindrical member made of a heat-resistant material such as quartz or SiC may be provided.

[0031] 2, a temperature sensor 263 is installed in the inner tube 204 as a temperature detector, and the temperature in the processing chamber 201a is configured to have a desired temperature distribution by adjusting the amount of electricity supplied to the heater 207 based on temperature information detected by the temperature sensor 263. The temperature sensor 263 is configured in an L-shape like the nozzles 410, 420, and 430, and is provided along the inner wall of the inner tube 204.

[0032] FIG. 3 is a vertical cross-sectional view of a processing furnace 202b serving as a second process unit included in the substrate processing apparatus 10, and FIG. 4 is a cross-sectional view of the processing furnace 202b taken along line AA. The processing furnace 202b in this embodiment is different from the processing furnace 202a in the configuration of the processing chamber 201a. In the processing furnace 202b, only the parts different from the processing furnace 202a will be described below, and the description of the same parts will be omitted. The processing furnace 202b includes a processing chamber 201b as a second processing chamber.

[0033] Nozzles 440, 450 are provided in the processing chamber 201b so as to penetrate the sidewall of the manifold 209 and the inner tube 204. Gas supply pipes 340, 350 are connected to the nozzles 440, 450, respectively. However, the processing furnace 202b of this embodiment is not limited to the above-mentioned configuration.

[0034] Gas supply pipes 340, 350 are respectively provided with MFCs 342, 352 in order from the upstream side. Furthermore, gas supply pipes 340, 350 are respectively provided with valves 344, 354. Gas supply pipes 540, 550 for supplying inert gas are connected to the downstream side of valves 344, 354 of gas supply pipes 340, 350, respectively. Gas supply pipes 540, 550 are respectively provided with MFCs 542, 552 and valves 544, 554 in order from the upstream side.

[0035] Nozzles 440, 450 are connected to the tips of the gas supply pipes 340, 350, respectively. The nozzles 440, 450 are configured as L-shaped nozzles, and their horizontal parts are provided so as to penetrate the side wall of the manifold 209 and the inner tube 204. The vertical parts of the nozzles 440, 450 are provided inside the channel-shaped (groove-shaped) preliminary chamber 205b that protrudes radially outward from the inner tube 204 and is formed so as to extend in the vertical direction, and are provided in the preliminary chamber 205b facing upward (upward in the arrangement direction of the wafers 200) along the inner wall of the inner tube 204.

[0036] The nozzles 440 and 450 are provided to extend from a lower region of the processing chamber 201b to an upper region of the processing chamber 201b, and are provided with a plurality of gas supply holes 440a and 450a at positions facing the wafer 200, respectively.

[0037] The gas supply holes 440a, 450a of the nozzles 440, 450 are provided at a height from the bottom to the top of a boat 217 described later. Therefore, the process gas supplied from the gas supply holes 440a, 450a of the nozzles 440, 450 into the process chamber 201b is supplied to the entire area of ​​the wafers 200 accommodated in the boat 217 from the bottom to the top.

[0038] From the gas supply pipe 340, a gas containing a second metal element (hereinafter also referred to as a "second metal-containing gas") is supplied as a processing gas into the processing chamber 201b via the MFC 342, the valve 344, and the nozzle 440.

[0039] A first reaction gas that reacts with the second metal-containing gas is supplied as a process gas from the gas supply pipe 350 through the MFC 352, the valve 354, and the nozzle 450 into the process chamber 201b.

[0040] From the gas supply pipes 540 and 550, an inert gas such as N2 gas is supplied into the processing chamber 201b via the MFCs 542 and 552, the valves 544 and 554, and the nozzles 440 and 450. Note that, although an example in which N2 gas is used as the inert gas will be described below, other than N2 gas, a rare gas such as argon (Ar) gas, helium (He) gas, neon (Ne) gas, or xenon (Xe) gas may be used as the inert gas.

[0041] A process gas supply system (process gas supply unit) is mainly composed of the gas supply pipes 340 and 350, the MFCs 342 and 352, the valves 344 and 354, and the nozzles 440 and 450, but only the nozzles 440 and 450 may be considered as the process gas supply system. The process gas supply system may be simply referred to as a gas supply system. When the second metal-containing gas is caused to flow from the gas supply pipe 340, the second metal-containing gas supply system is mainly composed of the gas supply pipe 340, the MFCs 342, and the valve 344, but the nozzles 440 may be included in the second metal-containing gas supply system. When the first reactive gas is caused to flow from the gas supply pipe 350, the first reactive gas supply system is mainly composed of the gas supply pipe 350, the MFCs 352, and the valve 354, but the nozzles 450 may be included in the first reactive gas supply system. The first reactive gas supply system may also be referred to as a reduction gas supply system. Furthermore, when a hydrogen-containing gas is supplied as the first reactive gas from the gas supply pipe 350, the first reactive gas supply system can also be called a hydrogen-containing gas supply system. An inert gas supply system is mainly composed of the gas supply pipes 540 and 550, the MFCs 542 and 552, and the valves 544 and 554. The inert gas supply system can also be called a purge gas supply system, a dilution gas supply system, or a carrier gas supply system.

[0042] (Control Unit Configuration) 5, 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. The controller 121 is connected to an input / output device 122 configured as, for example, a touch panel.

[0043] The storage device 121c is composed of, for example, a flash memory, an HDD (Hard Disk Drive), etc. A control program for controlling the operation of the substrate processing apparatus, a process recipe describing the procedure and conditions of a manufacturing method for a semiconductor device described later, etc. are readably stored in the storage device 121c. The process recipe is a combination of processes (steps) in a manufacturing method for a semiconductor device described later that are executed by the controller 121 to obtain a predetermined result, and functions as a program. Hereinafter, the process recipe, the control program, etc. are collectively referred to simply as a program. When the word program is used in this specification, it may include only a process recipe, only a control program, or a combination of a process recipe and a control program. The RAM 121b is configured as a memory area (work area) in which programs and data read by the CPU 121a are temporarily stored.

[0044] The I / O port 121d is connected to the MFCs 312, 322, 332, 342, 352, 512, 522, 532, 542, 552, valves 314, 324, 334, 344, 354, 514, 524, 534, 544, 554, pressure sensor 245, APC valve 243, vacuum pump 246, heater 207, temperature sensor 263, rotation mechanism 267, boat elevator 115, gate valves 70a to 70d, first substrate transfer machine 112, etc. that are provided in the above-mentioned processing furnaces 202a, 202b, respectively.

[0045] The CPU 121a is configured to read and execute a control program from the storage device 121c, and also to read a recipe or the like from the storage device 121c in response to an input of an operation command from the input / output device 122, or the like. The CPU 121a is configured to control the flow rate adjustment of various gases by the MFCs 312, 322, 332, 342, 352, 512, 522, 532, 542, and 552, the opening and closing of the valves 314, 324, 334, 344, 354, 514, 524, 534, 544, and 554, the opening and closing 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 boat 217 by the rotation mechanism 267, the raising and lowering operation of the boat 217 by the boat elevator 115, the accommodation operation of the wafers 200 in the boat 217, and the like, in accordance with the contents of the read recipe.

[0046] The controller 121 can be configured by installing the above-mentioned program stored in an external storage device (for example, a magnetic tape, a magnetic disk such as a flexible disk or a hard disk, an optical disk such as a CD or a DVD, a magneto-optical disk such as an MO, or a semiconductor memory such as a USB memory or a memory card) 123 into a computer. The storage device 121c and the external storage device 123 are configured as computer-readable recording media. Hereinafter, these are collectively referred to simply as recording media. In this specification, the recording medium may include only the storage device 121c alone, may include only the external storage device 123 alone, or may include both of them. 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.

[0047] (2) Substrate processing process (film formation process) As one step in the manufacturing process of a semiconductor device, an example of a step of forming a first metal-containing film containing a first metal element on a wafer 200 in a process furnace 202a and a cap film on the first metal-containing film, and forming a second metal-containing film containing a second metal element on the wafer 200 in a process furnace 202b while removing at least a part of the cap film formed on the first metal-containing film will be described with reference to Figures 6, 7, and 8(A) to 8(C). In the following description, the operation of each part constituting the substrate processing apparatus 10 is controlled by a controller 121.

[0048] In the substrate processing process (semiconductor device manufacturing process) according to this embodiment, (a) preparing a substrate having a film containing a first metal element and a film containing a Group 13 element or a Group 14 element formed on the film containing the first metal element; (b) supplying a gas containing a second metal element to the substrate; (c) supplying a first reactive gas to the substrate; having (d) performing (b) and (c) to form a film containing the second metal element on the substrate while removing at least a part of the film containing the Group 13 element or the Group 14 element formed on the film containing the first metal element; has.

[0049] In this specification, the term "wafer" may mean "the wafer itself" or "a laminate (assembly) of a wafer and a predetermined layer, film, etc. formed on its surface" (i.e., the wafer is referred to as including the predetermined layer, film, etc. formed on the surface). In addition, in this specification, the term "surface of a wafer" may mean "the surface (exposed surface) of the wafer itself" or "the surface of a predetermined layer, film, etc. formed on a wafer, i.e., the outermost surface of the wafer as a laminate." In addition, in this specification, the term "substrate" is synonymous with the term "wafer."

[0050] A. Formation of the First Metal-Containing Film First, a wafer 200 is loaded into a processing furnace 202a serving as a first process unit, and a first metal-containing film containing a first metal element and a cap film containing a Group 13 element or a Group 14 element are formed on the wafer 200.

[0051] (Wafer loading) 1, when a plurality of wafers 200 are loaded into the boat 217 (wafer charge), the boat 217 supporting the plurality of wafers 200 is lifted by the boat elevator 115 and carried into the processing chamber 201a (boat load). In this state, the seal cap 219 closes the lower end opening of the outer tube 203 via the O-ring 220b.

[0052] (Pressure and temperature regulation) The inside of the processing chamber 201a, i.e., the space in which the wafer 200 exists, is evacuated by the vacuum pump 246 so as to reach a desired pressure (vacuum level). At this time, the pressure inside the processing chamber 201a is measured by the pressure sensor 245, and the APC valve 243 is feedback-controlled based on the measured pressure information (pressure adjustment). The inside of the processing chamber 201a is heated by the heater 207 so as to reach a desired temperature. At this time, the amount of electricity supplied to the heater 207 is feedback-controlled based on temperature information detected by the temperature sensor 263 so as to achieve a desired temperature distribution inside the processing chamber 201a (temperature adjustment). The rotation mechanism 267 also starts rotating the wafer 200. The evacuation inside the processing chamber 201a and the heating and rotation of the wafer 200 are all continued at least until the processing of the wafer 200 is completed.

[0053] [First metal-containing film forming step] Subsequently, a step of forming a first metal-containing film on the wafer 200 is performed.

[0054] (First metal-containing gas supply step S10) The valve 314 is opened to allow the first metal-containing gas to flow into the gas supply pipe 310. The flow rate of the first metal-containing gas is adjusted by the MFC 312, and the first metal-containing gas is supplied into the processing chamber 201a from the gas supply hole 410a of the nozzle 410, and is exhausted from the exhaust pipe 231. At this time, the valve 514 is opened at the same time to allow an inert gas such as N2 gas to flow into the gas supply pipe 510. The inert gas flowing through the gas supply pipe 510 is adjusted in flow rate by the MFC 512, and is supplied into the processing chamber 201a together with the first metal-containing gas, and is exhausted from the exhaust pipe 231. At this time, in order to prevent the first metal-containing gas from entering the nozzles 420 and 430, the valves 524 and 534 are opened to allow the inert gas to flow into the gas supply pipes 520 and 530. The inert gas is supplied into the processing chamber 201 a via gas supply pipes 320 and 330 and nozzles 420 and 430 , and is exhausted from an exhaust pipe 231 .

[0055] At this time, the APC valve 243 is adjusted to set the pressure in the process chamber 201 to, for example, 1 to 3990 Pa. The supply flow rate of the first metal-containing gas controlled by the MFC 312 is, for example, 0.1 to 2.0 slm. The supply flow rates of the inert gases controlled by the MFCs 512, 522, and 532 are, for example, 0.1 to 20 slm. In the following, the temperature of the heater 207 is set to a temperature such that the temperature of the wafer 200 is, for example, within a range of 300 to 650° C. The time for which the first metal-containing gas is supplied to the wafer 200 is, for example, within a range of 0.01 to 30 seconds. In this disclosure, the expression of a numerical range such as “1 to 3990 Pa” means that the lower limit and the upper limit are included in the range. Therefore, for example, “1 to 3990 Pa” means “1 Pa or more and 3990 Pa or less”. The same applies to other numerical ranges.

[0056] At this time, a first metal-containing gas is supplied to the wafer 200. Here, as the first metal-containing gas, for example, a gas containing titanium (Ti) as a first metal element is used, and as an example, titanium tetrachloride (TiCl4) gas containing a halogen element can be used.

[0057] (Purge step S11) After a predetermined time has elapsed since the supply of the first metal-containing gas was started, the valve 314 is closed to stop the supply of the first metal-containing gas. At this time, the APC valve 243 of the exhaust pipe 231 is left open, and the inside of the processing chamber 201a is evacuated by the vacuum pump 246 to remove the first metal-containing gas remaining in the processing chamber 201a, which has not reacted or which has contributed to the formation of the first metal-containing film, from the inside of the processing chamber 201a. At this time, the valves 514, 524, and 534 are left open to maintain the supply of the inert gas into the processing chamber 201a. The inert gas acts as a purge gas, and can enhance the effect of removing the first metal-containing gas remaining in the processing chamber 201a, which has not reacted or which has contributed to the formation of the first metal-containing film, from the inside of the processing chamber 201a.

[0058] (Third reaction gas supply step S12) After a predetermined time has elapsed since the start of purging, valve 324 is opened to allow a third reactive gas to flow into gas supply pipe 320. The flow rate of the third reactive gas is adjusted by MFC 322, and the third reactive gas is supplied into processing chamber 201a from gas supply hole 420a of nozzle 420 and exhausted from exhaust pipe 231. At the same time, valve 524 is opened to allow an inert gas to flow into gas supply pipe 520. Furthermore, in order to prevent the third reactive gas from entering nozzles 410 and 430, valves 514 and 534 are opened to allow an inert gas to flow into gas supply pipes 510 and 530.

[0059] At this time, the APC valve 243 is adjusted to set the pressure inside the processing chamber 201a within a range of, for example, 1 to 3990 Pa. The supply flow rate of the third reactive gas controlled by the MFC 322 is within a range of, for example, 0.1 to 30 slm. The supply flow rates of the inert gases controlled by the MFCs 512, 522, and 532 are each within a range of, for example, 0.1 to 20 slm. The time for which the third reactive gas is supplied to the wafer 200 is within a range of, for example, 0.01 to 30 seconds.

[0060] At this time, a third reaction gas is supplied to the wafer 200. Here, as the third reaction gas, for example, a N-containing gas containing nitrogen (N) is used. As the N-containing gas, for example, ammonia (NH3) gas can be used.

[0061] (Purge step S13) After a predetermined time has elapsed since the supply of the third reactive gas started, the valve 324 is closed to stop the supply of the third reactive gas. Then, by a process procedure similar to that of step S11, the third reactive gas remaining in the process chamber 201a, which has not reacted or which has contributed to the formation of the first metal-containing film, is removed from the process chamber 201a.

[0062] (Performed a set number of times) By performing the cycle of steps S10 to S13 in order one or more times (a predetermined number of times (p times)), a first metal-containing film containing a first metal element and having a predetermined thickness is formed on the wafer 200, as shown in FIG. 8(A). It is preferable to repeatedly perform the above-mentioned cycle multiple times. Here, for example, a TiN film is formed as the first metal-containing film on the wafer 200.

[0063] [Cap film formation process] Next, a step of forming a cap film is performed on the wafer 200 having the first metal-containing film formed on the surface thereof. The cap film is a Group 13 or Group 14 element-containing film that contains a Group 13 or Group 14 element, and functions as an oxidation prevention film that prevents oxidation of the outermost surface of the first metal-containing film described above.

[0064] (Supplying Group 13 or Group 14 Element-Containing Gas Step S20) The valve 334 is opened to allow a group 13 element or group 14 element-containing gas to flow into the gas supply pipe 330. The flow rate of the group 13 element or group 14 element-containing gas is adjusted by the MFC 332, and the gas is supplied into the processing chamber 201a from the gas supply hole 430a of the nozzle 430 and exhausted from the exhaust pipe 231. At the same time, the valve 534 is opened to allow an inert gas to flow into the gas supply pipe 530. Furthermore, in order to prevent the group 13 element or group 14 element-containing gas from entering the nozzles 410 and 420, the valves 514 and 524 are opened to allow an inert gas to flow into the gas supply pipes 510 and 520.

[0065] At this time, the APC valve 243 is adjusted to set the pressure inside the processing chamber 201 within a range of, for example, 1 to 3990 Pa. The supply flow rate of the Group 13 element or Group 14 element containing gas controlled by the MFC 332 is set within a range of, for example, 0.1 to 30 slm. The supply flow rates of the inert gases controlled by the MFCs 512, 522, and 532 are each set within a range of, for example, 0.1 to 20 slm. The time for which the Group 13 element or Group 14 element containing gas is supplied to the wafer 200 is set within a range of, for example, 0.01 to 30 seconds.

[0066] At this time, a group 13 element or group 14 element containing gas is supplied to the wafer 200 having the first metal-containing film formed on its surface. Here, as the group 13 element or group 14 element containing gas, for example, a Si-containing gas containing silicon (Si) is used, and dichlorosilane (SiH2Cl2, abbreviated as DCS) gas can be used as one example. By using the group 13 element or group 14 element containing gas, the cap film can be easily sublimated and removed when forming the second metal-containing film described later.

[0067] The Group 14 element is, for example, at least one of silicon (Si), germanium (Ge), etc. The Group 14 element-containing gas is, for example, a gas containing these elements and at least one of hydrogen (H), halogen elements (fluorine (F), chlorine (Cl)), and alkyl groups (for example, methyl group CH3). The Si-containing gas is, for example, a silane-based gas or a halosilane-based gas. The silane-based gas is, for example, a monosilane (SiH4) gas, a disilane (Si2H6) gas, and a trisilane (Si3H8) gas. The halosilane-based gas is, for example, a dichlorosilane (SiH2Cl2), a trichlorosilane (SiHCl3), a tetrachlorosilane (SiCl4), and a hexachlorodisilane (Si2Cl6) gas.

[0068] (Purge step S21) After a predetermined time has elapsed since the start of the supply of the gas containing a Group 13 element or a Group 14 element, the valve 334 is closed to stop the supply of the gas containing a Group 13 element or a Group 14 element. Then, by a process procedure similar to that of step S11, the gas containing a Group 13 element or a Group 14 element remaining in the process chamber 201a that has not reacted or that has contributed to the formation of the cap film is removed from the process chamber 201a.

[0069] (Third reaction gas supply step S22) After a predetermined time has elapsed since the start of purging, valve 324 is opened to allow a third reactive gas to flow into gas supply pipe 320. The flow rate of the third reactive gas is adjusted by MFC 322, and the third reactive gas is supplied into processing chamber 201a from gas supply hole 420a of nozzle 420 and exhausted from exhaust pipe 231. At the same time, valve 524 is opened to allow an inert gas to flow into gas supply pipe 520. Furthermore, in order to prevent the third reactive gas from entering nozzles 410 and 430, valves 514 and 534 are opened to allow an inert gas to flow into gas supply pipes 510 and 530.

[0070] At this time, the APC valve 243 is adjusted to set the pressure inside the processing chamber 201a within a range of, for example, 1 to 3990 Pa. The supply flow rate of the third reactive gas controlled by the MFC 322 is within a range of, for example, 0.1 to 30 slm. The supply flow rates of the inert gases controlled by the MFCs 512, 522, and 532 are each within a range of, for example, 0.1 to 20 slm. The time for which the third reactive gas is supplied to the wafer 200 is within a range of, for example, 0.01 to 30 seconds.

[0071] At this time, a third reactive gas is supplied to the wafer 200. Here, as the third reactive gas, for example, NH3 gas, which is a N-containing gas that contains N, can be used.

[0072] (Purge step S23) After a predetermined time has elapsed since the supply of the third reactive gas started, the valve 324 is closed to stop the supply of the third reactive gas. Then, by a process procedure similar to that of step S11, the third reactive gas remaining in the process chamber 201a that has not reacted or that has contributed to the formation of the cap film is removed from the process chamber 201a.

[0073] (Performed a set number of times) The above-mentioned cycle of steps S20 to S23 is repeated once or more (a predetermined number of times (n times)), to form a cap film of a predetermined thickness on the wafer 200 having the first metal-containing film formed on the surface thereof, as shown in FIG. 8(B). The above-mentioned cycle is preferably performed multiple times, and is preferably cyclically supplied. The thickness of the cap film formed here is preferably 0.2 to 3 nm. If the thickness of the cap film is made thicker than 3 nm, the cap film may remain without being removed even when the second metal-containing film forming step described later is performed. Also, if the thickness is made thinner than 0.2 nm, the first metal-containing film of the base may be oxidized. That is, during the second metal-containing film forming step, the oxidized first metal-containing film is etched, causing a deterioration in the characteristics of the first metal-containing film. Here, the deterioration in the characteristics of the first metal-containing film means that, when the first metal-containing film is a barrier film, the barrier performance is deteriorated. Therefore, the cap film is preferably formed to a thickness of 0.2 nm or more, which can suppress the oxidation of the first metal-containing film. By increasing the thickness of the cap film, the effect of suppressing oxidation of the first metal-containing film is increased, but the cap film may not be removed when the second metal-containing film is formed. Therefore, in this process, a cap film having a thickness of 0.2 to 3 nm, preferably 0.2 to 2 nm, is formed on the wafer 200 on which the first metal-containing film is formed on the surface. By making the thickness 2 nm or less, it becomes possible to remove the cap film during the second metal-containing film formation process. Here, as the cap film, for example, a silicon nitride (SiN) film, which is a film containing Si, a group 14 element, is formed. Here, 0.2 nm is the thickness of one atomic layer when the cap film is made of SiN. Since the thickness of one atomic layer varies depending on the type of cap film, the film thickness (number of layers) may be changed depending on the type of cap film. By forming a film having a thickness of one atomic layer, the effect of suppressing oxidation of the first metal-containing film is obtained. If the thickness is less than one atomic layer, holes are formed, and the effect of suppressing oxidation of the first metal-containing film becomes insufficient. In addition, by making the cap film several atomic layers thick, the effect of suppressing oxidation can be further obtained. Note that in a layer having a thickness of one atomic layer, pinholes may be formed, and the first metal-containing film may be oxidized through the pinholes.Therefore, the cap film is preferably two atomic layers or more and several atomic layers or less. By forming two atomic layers or more, the formation of pinholes can be suppressed. The pinholes can be generated due to steric hindrance caused by the molecular size of the source gas used in forming the cap film, the reaction characteristics of the source gas, and the reaction characteristics of the reaction gas. Furthermore, by making the thickness of the cap film several atomic layers, the second metal-containing film can be formed while removing at least a part of the cap film formed on the first metal-containing film during the formation process of the second metal-containing film. Here, when the cap film is SiN, the thickness of two atomic layers to several atomic layers is 0.4 to 1.8 nm. By making the thickness 1.8 nm or less, it is possible to remove the cap film at an early stage of the second metal-containing film formation process, and the layer in which the second metal-containing film and the cap film are mixed can be reduced. In the layer in which the second metal-containing film and the cap film are mixed, the electrical properties of the second metal-containing film may be deteriorated.

[0074] (After purging and atmospheric pressure recovery) An inert gas is supplied into the processing chamber 201a through the gas supply pipes 510, 520, and 530, and exhausted through the exhaust pipe 231. The inert gas acts as a purge gas, and the processing chamber 201a is purged with the inert gas, and gas and by-products remaining in the processing chamber 201a are removed from the processing chamber 201a (after-purge). Thereafter, the atmosphere in the processing chamber 201a is replaced with the inert gas (inert gas replacement), and the pressure in the processing chamber 201a is returned to normal pressure (return to atmospheric pressure).

[0075] (Wafer removal) Thereafter, the seal cap 219 is lowered by the boat elevator 115 to open the lower end of the outer tube 203. Then, the processed wafer 200, in which the first metal-containing film is formed on the wafer 200 and the cap film is formed on the first metal-containing film, is carried out from the lower end of the outer tube 203 to the outside of the outer tube 203 (boat unloading) while being supported by the boat 217. Thereafter, the processed wafer 200 is taken out of the boat 217 (wafer discharging).

[0076] B. Formation of a Second Metal-Containing Film Next, the wafer 200 that has been processed in the processing furnace 202a is loaded into the processing furnace 202b as the second process unit. That is, the wafer 200 having the first metal-containing film and the cap film formed on the first metal-containing film is prepared in the processing furnace 202b. Then, the pressure and temperature in the processing chamber 201b are adjusted to a desired pressure and a desired temperature distribution. Note that this process differs from the process in the processing furnace 202a described above only in the gas supply process. Therefore, only the parts that are different from the process in the processing furnace 202a described above will be described below, and the same parts will not be described.

[0077] [Second metal-containing film forming step] Next, a step of forming a second metal-containing film containing a second metal element is performed on the wafer 200 having a cap film formed on its surface, while removing at least a portion of the cap film formed on the first metal-containing film.

[0078] (Second metal-containing gas supply step S30) The valve 344 is opened to allow the second metal-containing gas to flow into the gas supply pipe 340. The flow rate of the second metal-containing gas is adjusted by the MFC 342, and the second metal-containing gas is supplied into the processing chamber 201b from the gas supply hole 440a of the nozzle 440, and is exhausted from the exhaust pipe 231. At this time, the valve 544 is opened at the same time to allow an inert gas such as N2 gas to flow into the gas supply pipe 540. The inert gas flowing through the gas supply pipe 540 is adjusted in flow rate by the MFC 542, and is supplied into the processing chamber 201b together with the second metal-containing gas, and is exhausted from the exhaust pipe 231. At this time, in order to prevent the second metal-containing gas from entering the nozzle 450, the valve 554 is opened to allow the inert gas to flow into the gas supply pipe 550. The inert gas is supplied into the processing chamber 201b via the gas supply pipe 350 and the nozzle 450, and is exhausted from the exhaust pipe 231.

[0079] At this time, the APC valve 243 is adjusted to set the pressure in the process chamber 201 within a range of, for example, 0.1 to 6650 Pa. The supply flow rate of the second metal-containing gas controlled by the MFC 342 is within a range of, for example, 0.01 to 10 slm. The supply flow rates of the inert gas controlled by the MFCs 542 and 552 are each within a range of, for example, 0.1 to 20 slm. The time for supplying the second metal-containing gas to the wafer 200 is within a range of, for example, 0.01 to 30 seconds. At this time, the temperature of the heater 207 is set to a temperature such that the temperature of the wafer 200 is within a range of, for example, 250 to 550° C. The gases flowing in the process chamber 201b are only the second metal-containing gas and the inert gas, and the second metal-containing gas is supplied to remove the cap film on the wafer 200 while forming a second metal-containing film having a thickness of, for example, less than one atomic layer to several atomic layers on the wafer 200 (underlying film on the surface).

[0080] At this time, the second metal-containing gas is supplied to the wafer 200 having the cap film formed on the surface thereof. Here, as the second metal-containing gas, for example, tungsten hexafluoride (WF6) gas can be used as a halogen-containing gas containing tungsten (W) as the second metal element and fluorine (F) as the halogen element.

[0081] At this time, the cap film is sublimated by supplying the second metal-containing gas. That is, the cap film reacts with the halogen element contained in the second metal-containing gas, and the cap film is removed (etched). Specifically, by supplying WF6 gas, which is an example of the second metal-containing gas, to a SiN film, which is an example of the cap film, SiN reacts with WF6, W is adsorbed on the surface of the wafer 200, and silicon tetrafluoride (SiF4) and N2 are generated. Since SiF4 is easily sublimated, SiF4 is sublimated, and N2 is removed by purging in the next step S31. That is, the cap film is removed.

[0082] Here, the removal of the cap film may include a state in which a part of the cap film remains. In other words, a part of the cap film may remain in the second metal-containing film. In a device structure, for example, a TiN film may be formed on an aluminum oxide (AlO) film, and a W film may be formed on the TiN film. In this case, the W film functions as an electrode, and the TiN film does not function as an electrode. For this reason, even if an insulating film exists between the W film and the TiN film, it has little effect on the electrical characteristics of each film.

[0083] (Purge step S31) After a predetermined time has elapsed since the supply of the second metal-containing gas was started, the valve 344 is closed to stop the supply of the second metal-containing gas. At this time, the APC valve 243 of the exhaust pipe 231 is left open, and the inside of the processing chamber 201b is evacuated by the vacuum pump 246, and the second metal-containing gas remaining in the processing chamber 201b after the removal of the unreacted gas or the cap film and the contribution to the formation of the second metal-containing film is removed from the inside of the processing chamber 201b. At this time, the valves 544 and 554 are left open to maintain the supply of the inert gas into the processing chamber 201b. The inert gas acts as a purge gas, and can enhance the effect of removing the second metal-containing gas remaining in the processing chamber 201b after the removal of the unreacted gas or the cap film and the contribution to the formation of the second metal-containing film from the inside of the processing chamber 201b.

[0084] (First reaction gas supply step S32) After a predetermined time has elapsed since the start of purging, the valve 354 is opened to allow the first reaction gas to flow into the gas supply pipe 350. The flow rate of the first reaction gas is adjusted by the MFC 352, and the first reaction gas is supplied into the processing chamber 201b from the gas supply hole 450a of the nozzle 450, and is exhausted from the exhaust pipe 231. At the same time, the valve 554 is opened to allow the inert gas to flow into the gas supply pipe 550. The inert gas flowing through the gas supply pipe 550 is adjusted by the MFC 552, and is supplied into the processing chamber 201b together with the first reaction gas, and is exhausted from the exhaust pipe 231. At this time, in order to prevent the first reaction gas from entering the nozzle 440, the valve 544 is opened to allow the inert gas to flow into the gas supply pipe 540. The inert gas is supplied into the processing chamber 201b via the gas supply pipe 340 and the nozzle 440, and is exhausted from the exhaust pipe 231.

[0085] At this time, the APC valve 243 is adjusted to set the pressure in the process chamber 201b to, for example, 1 to 3990 Pa. The supply flow rate of the first reactive gas controlled by the MFC 352 is, for example, 0.1 to 50 slm. The supply flow rates of the inert gas controlled by the MFCs 542 and 552 are, for example, 0.1 to 20 slm. The time for supplying the first reactive gas to the wafer 200 is, for example, 0.1 to 20 seconds. At this time, the temperature of the heater 207 is set to a temperature such that the temperature of the wafer 200 is, for example, 200 to 600° C. The gases flowing in the process chamber 201b are only the first reactive gas and the inert gas, and the cap film on the wafer 200 is removed by the supply of the first reactive gas, and a second metal-containing film having a thickness of, for example, less than one atomic layer to several atomic layers is formed on the wafer 200 (underlying film on the surface) of the wafer 200.

[0086] At this time, the first reactive gas is supplied to the cap film formed on the surface of the wafer 200. As the first reactive gas, for example, a reducing gas, which may be hydrogen (H2) gas, which is a gas containing hydrogen (H) (hereinafter also referred to as a "hydrogen-containing gas"), may be used.

[0087] The supply of the first reactive gas removes the halogen elements in the film, and the cap film is further removed. Specifically, WF6 gas, which is an example of the second metal-containing gas, and H2 gas, which is an example of the first reactive gas, are supplied to the wafer 200 having the cap film formed on its surface, and WF6 and H2 react to generate hydrogen fluoride (HF), forming a W film from which F in the film has been removed. Furthermore, the HF generated by this reaction removes the SiN film as the cap film. That is, the cap film is removed by the halogen elements contained in the second metal-containing gas, and the cap film is further removed by the HF generated by the supply of the second metal-containing gas and the first reactive gas.

[0088] In other words, by forming a cap film on the first metal-containing film, the oxidation of the first metal-containing film is suppressed, and the cap film can be sublimated and disappeared when the second metal-containing film is formed on the cap film, which means that the second metal-containing film can be formed with a low content of Group 13 elements or Group 14 elements in the cap film.

[0089] Here, the supply flow rate of the first reactive gas is made smaller than the supply flow rate of the second metal-containing gas described above, and after a predetermined period of time has elapsed (after a predetermined number of times), it is changed to a flow rate that is approximately the same as the supply flow rate of the second metal-containing gas. Here, the approximately same flow rate includes an error of about 10%. In this way, by initially supplying the supply flow rate of the second metal-containing gas larger than the supply flow rate of the first reactive gas, the reaction between the halogen element contained in the second metal-containing gas and the cap film is promoted, and the cap film is removed. Then, after the predetermined period of time has elapsed and the cap film has been removed, the supply flow rate of the first reactive gas is made approximately the same as the supply flow rate of the second metal-containing gas, and the reaction between the first reactive gas and the second metal-containing gas is promoted, and a second metal-containing film with a small amount of halogen elements is formed. In other words, it is possible to form a second metal-containing film with a small amount of halogen elements on the first metal-containing film while suppressing the first metal-containing film from being etched by the formation of the second metal-containing film.

[0090] Also, the supply flow rate of the first reactive gas may be initially set to a flow rate higher than the supply flow rate of the inert gas as the carrier gas, and after a predetermined period of time (after a predetermined number of times), the supply flow rate may be changed to a flow rate lower than the supply flow rate of the inert gas. In this way, by initially supplying the first reactive gas at a flow rate higher than the supply flow rate of the carrier gas, the reaction between the second metal-containing gas and the first reactive gas is promoted, the amount of HF generated increases, and the cap film is removed. Then, after the predetermined period of time has elapsed and the cap film has been removed, the supply flow rate of the first reactive gas is reduced compared to the supply flow rate of the inert gas, thereby suppressing the generation of reaction by-products.

[0091] (Purge step S33) After a predetermined time has elapsed since the supply of the first reaction gas started, the valve 354 is closed to stop the supply of the first reaction gas. Then, by a process procedure similar to that of step S11, the first reaction gas remaining in the process chamber 201b, which has not reacted or has contributed to the removal of the cap film and the formation of the second metal-containing film, is removed from the process chamber 201.

[0092] (Performed a set number of times) By repeating the cycle of sequentially performing the above-mentioned steps S30 to S33 one or more times (a predetermined number (m times)), it is possible to form a second metal-containing film containing a second metal element with a predetermined thickness on the wafer 200 while sublimating the cap film formed on the wafer 200. That is, as shown in FIG. 8(C), it is possible to form a second metal-containing film with a predetermined thickness on the wafer 200 while removing at least a part of the cap film formed on the first metal-containing film. It is preferable to perform the above-mentioned cycle multiple times, and the number of cycles (m times) in the second metal-containing film formation process is made larger than the number of cycles (n times) in the above-mentioned cap film formation process. That is, m>n (m and n are positive integers). Thereby, it is possible to form a second metal-containing film with a predetermined thickness on the wafer 200 while sublimating the cap film formed on the wafer 200.

[0093] (After purging and atmospheric pressure recovery) An inert gas is supplied into the processing chamber 201b from each of the gas supply pipes 540 and 550, and exhausted from the exhaust pipe 231. The inert gas acts as a purge gas, and the processing chamber 201b is purged with the inert gas, and gas and by-products remaining in the processing chamber 201b are removed from the processing chamber 201b (after-purge). Thereafter, the atmosphere in the processing chamber 201b is replaced with the inert gas (inert gas replacement), and the pressure in the processing chamber 201b is returned to normal pressure (return to atmospheric pressure).

[0094] (Wafer removal) Thereafter, the seal cap 219 is lowered by the boat elevator 115 to open the lower end of the outer tube 203. Then, the processed wafers 200 supported by the boat 217 are unloaded from the lower end of the outer tube 203 to the outside of the outer tube 203 (boat unloading). Thereafter, the processed wafers 200 are removed from the boat 217 (wafer discharging).

[0095] (3) Effects of this embodiment According to this embodiment, one or more of the following effects can be obtained. (a) The film properties can be improved. (b) In particular, oxidation of the surface of the barrier film (first metal-containing film) can be suppressed. (c) Then, etching of the barrier film can be suppressed, and the barrier properties of the barrier film can be improved. (d) The resistivity of the metal-containing film (second metal-containing film) formed on the barrier film can be reduced. (e) The properties of a metal-containing film formed on a barrier film can be improved.

[0096] <Other embodiments> Although the embodiments of the present disclosure have been specifically described above, the present disclosure is not limited to the above-described embodiments and can be modified in various ways without departing from the spirit and scope of the present disclosure.

[0097] (Modification) FIG. 9 shows a modified example of the substrate processing sequence in one embodiment of the present disclosure. This modified example differs from the above-mentioned embodiment in the second metal-containing film formation step. That is, in the second metal-containing film formation step, a second metal-containing gas supply and a first reaction gas supply are performed to form a second metal-containing film of a predetermined thickness on the wafer 200 while removing at least a portion of the cap film, and then a second metal-containing gas supply and a second reaction gas supply that supplies a second reaction gas different from the first reaction gas are performed to form another film containing a second metal element on the second metal-containing film. Here, the other film containing the second metal element formed on the second metal-containing film contains the second metal element contained in the second metal-containing film and has a lower resistivity than the second metal-containing film. This modified example allows a second metal-containing film with a lower resistivity to be formed while removing at least a portion of the cap film.

[0098] Here, when WF6 gas is used as the second metal-containing gas, H2 gas as the first hydrogen-containing gas as the first reactive gas, and B2H6 gas as the second hydrogen-containing gas as the second reactive gas, WF6 gas supply and H2 gas supply are performed a predetermined number of times (m times) to remove at least a part of the SiN film, which is an example of a cap film formed on the first metal-containing film, and form a W film with little residual SiN and F on the wafer 200. Then, WF6 gas supply and B2H6 gas supply are performed a predetermined number of times (q times) to form a W film with low resistivity. That is, a second metal-containing film with low resistivity can be formed on the first metal-containing film while suppressing the first metal-containing film from being etched by the formation of the second metal-containing film.

[0099] In the above embodiment, an example in which DCS gas is used as the Group 13 element or Group 14 element-containing gas in the cap film formation process has been described, but the present invention is not limited to this and can be applied to cases in which a different gas is used. For example, the present invention can be applied to cases in which hexachlorodisilane (Si2Cl6, abbreviated as HCDS) gas or the like is used as the Group 13 element or Group 14 element-containing gas. When HCDS gas is supplied as the Group 13 element or Group 14 element-containing gas and NH3 gas is supplied as the third reaction gas, Si2Cl6 and NH3 react to produce Si x N y Chlorine (Cl2) and hydrochloric acid (HCl) are generated, and a SiN film can be formed as a cap film on the wafer 200 having the first metal-containing film formed on the surface thereof.

[0100] In the above embodiment, the example of using H2 gas as the first reaction gas in the second metal-containing film forming process has been described, but the present invention is not limited to this, and can be applied to the case of using a different gas. For example, the present invention can be applied to the case of using monosilane (SiH4) gas or disilane (Si2H6) gas, which is a gas containing silicon (Si) and hydrogen (H), as the first reaction gas. By using a gas containing Si and H, such as SiH4 gas, as the first reaction gas, the reaction is promoted and the amount of HF generated increases, compared to the case of using the above-mentioned H2 gas, and it is possible to promote etching (removal) of the SiN film by HF.

[0101] The above embodiment can also be applied to the case where diborane (B2H6) gas or monoborane (BH3) gas, which is a gas containing boron (B) and hydrogen (H), is used as the first reaction gas in the second metal-containing film formation process. By using a gas containing B and H, such as B2H6 gas, as the first reaction gas, the reaction is promoted and the amount of HF generated increases, compared to the case where H2 gas is used as described above, and it becomes possible to promote etching (removal) of the SiN film by HF. In addition, it becomes possible to reduce the resistivity of the second metal-containing film, such as a W film, formed on the first metal-containing film, such as a TiN film.

[0102] Here, SiH4 and B2H6 have a property of being easily reactive with WF6 compared to H2. Therefore, by using SiH4 gas or B2H6 gas as the first reactive gas, the reaction with WF6 is promoted, the amount of HF generated can be increased, and the removal of the SiN film by HF can be promoted. Note that, due to the reaction between WF6 and SiH4 (or B2H6), a W film may be formed before the SiN film is removed, and the SiN film may remain under the W film. Also, when H2 gas is used as the first reactive gas, the reaction with WF6 is slower and the amount of remaining SiN film is smaller compared to when SiH4 gas or B2H6 gas is used.

[0103] In the above embodiment, the first metal-containing film forming process and the cap film forming process are performed in the same processing furnace 202a (in-situ), and then the second metal-containing film forming process is performed in the processing furnace 202b (ex-situ), thereby suppressing oxidation of the surface of the first metal-containing film and forming the second metal-containing film on the first metal-containing film. However, the present invention is not limited to this, and the second metal-containing film forming process may be performed continuously in the same processing furnace as the first metal-containing film forming process and the cap film forming process. That is, the wafer 200 having the cap film formed on the surface may be continuously performed in the state of being accommodated in the processing chamber 201a without being taken out of the processing chamber 201a. That is, the processes may be continuously performed in the same processing chamber (in-situ).

[0104] In the above embodiment, an example of using a TiN film as the first metal-containing film has been described, but the present invention is not limited to this and can also be applied to cases where a metal-containing film such as a molybdenum (Mo)-containing film, a ruthenium (Ru)-containing film, or a copper (Cu)-containing film is used.

[0105] In the above embodiment, an example of using a SiN film as the cap film containing a Group 13 element or a Group 14 element has been described, but the present invention is not limited to this, and can be applied to a film containing Group 13 elements such as boron (B), aluminum (Al), gallium (Ga), indium (In), or a film containing Group 14 elements such as Si or germanium (Ge). For example, a nitride film such as an aluminum nitride (AlN) film can be used as the cap film in addition to the SiN film. These films can suppress oxidation of the underlying metal-containing film, and can be sublimated and disappeared when a metal-containing film different from the underlying metal-containing film is formed on the cap film. The SiN film is more likely to sublime and disappear than the AlN film.

[0106] In addition, the Group 13 element-containing gas may be, for example, a gas containing at least one of these elements, hydrogen (H), halogen elements (fluorine (F), chlorine (Cl)), and an alkyl group (e.g., a methyl group CH3). The Al-containing gas may be, for example, trimethylaluminum (Al(CH3)3) gas or aluminum trichloride (AlCl3) gas. By using such a gas, an AlN film can be formed.

[0107] In the above embodiment, an example was described in which purging was performed between each step in the second metal-containing film formation process, but this is not limited thereto, and purging does not have to be performed between each step in the second metal-containing film formation process, and the second metal-containing gas and the first reactive gas, or the second metal-containing gas and the second reactive gas, may be supplied simultaneously.

[0108] Examples will be described below, but the present disclosure is not limited to these examples. EXAMPLES

[0109] First, as shown in FIG. 10(A), using the processing furnace 202a of the above-mentioned substrate processing apparatus 10, sample 1 was prepared in which a TiN film and a SiN film as a cap film were formed on a wafer 200 by performing the first metal-containing film formation process and the cap film formation process in the above-mentioned substrate processing sequence of FIG. 6, and sample 2 was prepared in which a TiN film was formed on a wafer by performing only the first metal-containing film formation process in the above-mentioned substrate processing sequence of FIG. 6, and X-ray photoelectron spectroscopy (abbreviation: XPS) analysis was performed on the surfaces of sample 1 and sample 2.

[0110] As shown in Figures 10(B) and 10(C), the peak values ​​for Sample 1 and Sample 2 are different, and it was confirmed that the formation of a cap film on the TiN film suppresses the TiO component and inhibits the oxidation of the TiN film.

[0111] Next, as shown in FIG. 11(A), the substrate processing sequence of FIG. 7 was performed using the processing furnace 202b of the above-mentioned substrate processing apparatus 10 to form W films on the surfaces of the above-mentioned Sample 1 and Sample 2, respectively, and XPS analysis was performed on the surfaces of Sample 1 and Sample 2.

[0112] As shown in Fig. 11(B), the Ti2p intensity of sample 1 was higher than that of sample 2, and it was confirmed that a large amount of TiN film remained. In other words, it was confirmed that the formation of the cap film suppressed the etching of the TiN film during the W film formation. In addition, as shown in Fig. 10(C) and Fig. 11(C), it was confirmed that the peak value of the cap film disappeared, and the cap film was removed by forming the W film on the cap film.

[0113] Various typical embodiments and examples of the present disclosure have been described above, but the present disclosure is not limited to those embodiments and examples, and they can be used in appropriate combination. [Explanation of symbols]

[0114] 10 Substrate processing equipment 121 Controller 200 wafers (substrates) 201a, 201b Processing chamber 202a, 202b Processing furnace

Claims

1. (a) preparing a substrate having a film containing titanium, molybdenum, ruthenium, or copper as a first metal element, and a film containing boron, aluminum, gallium, or indium as a Group 13 element, or silicon or germanium as a Group 14 element, formed on the film containing the first metal element; (b) supplying a gas containing tungsten as a second metal element and a halogen to the substrate; (c) supplying a first reactive gas to the substrate; having (d) performing (b) and (c) to remove at least a portion of the film containing the Group 13 element or the Group 14 element, thereby forming a film containing the second metal element; A substrate processing method comprising the steps of:

2. 2. The substrate processing method according to claim 1, wherein the first reactive gas is a reducing gas.

3. 2. The substrate processing method according to claim 1, wherein the first reactive gas is a hydrogen-containing gas.

4. 4. The substrate processing method according to claim 3, wherein the hydrogen-containing gas is hydrogen gas.

5. 2. The substrate processing method according to claim 1, wherein the first reactive gas is a gas containing silicon and hydrogen.

6. 2. The substrate processing method according to claim 1, wherein the first reactive gas is a gas containing boron and hydrogen.

7. (e) supplying a second reactive gas to the substrate, the second reactive gas being different from the first reactive gas; 2. The substrate processing method according to claim 1, further comprising the steps of (f) and (d) followed by (b) and (e) to form another film containing the second metal element on the film containing the second metal element.

8. 8. The substrate processing method according to claim 7, wherein the first reactive gas is a first hydrogen-containing gas, and the second reactive gas is a second hydrogen-containing gas.

9. 2. The substrate processing method according to claim 1, wherein the film containing the Group 13 element or the Group 14 element is a film that suppresses oxidation of the surface of the film containing the first metallic element.

10. 2. The method of claim 1, wherein the halogen is fluorine.

11. 2. The substrate processing method according to claim 1, wherein in (d), a film containing the second metal element is formed on the film containing the Group 13 element or the Group 14 element from which the at least a portion has been removed.

12. 2. The substrate processing method according to claim 1, wherein in step (d), a film containing the second metal element is formed on the substrate.

13. 2. The substrate processing method according to claim 1, wherein in (d), a film containing the second metal element is formed on the film containing the first metal element.

14. 2. The substrate processing method according to claim 1, wherein in (d), the film containing the Group 13 element or the Group 14 element is removed to form the film containing the second metal element.

15. 2. The substrate processing method according to claim 1, wherein the thickness of the film containing the Group 13 element or the Group 14 element in (a) is greater than or equal to one atomic layer and less than or equal to several atomic layers.

16. (a) preparing a substrate having a film containing titanium, molybdenum, ruthenium, or copper as a first metal element, and a film containing boron, aluminum, gallium, or indium as a Group 13 element, or silicon or germanium as a Group 14 element, formed on the film containing the first metal element; (b) supplying a gas containing tungsten as a second metal element and a halogen to the substrate; (c) supplying a first reactive gas to the substrate; (d) performing (b) and (c) to remove at least a portion of the film containing the Group 13 element or the Group 14 element, thereby forming a film containing the second metal element; A program for causing a computer to execute the above in a substrate processing apparatus.

17. a gas supply system that supplies a gas containing tungsten and a halogen as a second metal element and a first reactive gas to a substrate having a film containing titanium, molybdenum, ruthenium, or copper as a first metal element and a film containing boron, aluminum, gallium, or indium as a Group 13 element, or silicon or germanium as a Group 14 element, formed on the film containing the first metal element; (a) preparing the substrate; (b) supplying a gas containing the second metal element and fluorine to the substrate; (c) supplying the first reaction gas to the substrate; having (d) a control unit configured to be capable of controlling the gas supply system to perform a process of performing the processes (b) and (c) to remove at least a portion of the film containing the Group 13 element or the Group 14 element and form a film containing the second metal element; and A substrate processing apparatus comprising:

18. (a) preparing a substrate having a film containing titanium, molybdenum, ruthenium, or copper as a first metal element, and a film containing boron, aluminum, gallium, or indium as a Group 13 element, or silicon or germanium as a Group 14 element, formed on the film containing the first metal element; (b) supplying a gas containing tungsten as a second metal element and a halogen to the substrate; (c) supplying a first reactive gas to the substrate; having (d) performing (b) and (c) to remove at least a portion of the film containing the Group 13 element or the Group 14 element, thereby forming a film containing the second metal element; A method for manufacturing a semiconductor device having the above structure.

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