Formation method for silicon film and system for forming silicon film

Abstract

To provide a formation method for a silicon film of selectively depositing a silicon film on a bottom of a recess and a system for forming a silicon film.SOLUTION: A formation method for a silicon film comprises the steps of: preparing a substrate comprising a ground part 700 including an epitaxial layer 701 formed by epitaxial growth and an insulation film 710 formed on the ground part and including a penetration part 720 which exposes the epitaxial layer; selectively forming a silicon film by supplying a silicon-containing gas; and removing the silicon film which is formed on a sidewall of the penetration part by supplying a halogen containing gas. In the step of forming the silicon film, the silicon film formed on a bottom of the penetration part is crystalline silicon, and the silicon film formed on the sidewall of the penetration part is an amorphous silicon film 703. In the step of removing the silicon film, the amorphous silicon film formed on the sidewall of the penetration part is selectively removed.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present disclosure relates to a method for forming a silicon film and a system for forming a silicon film. [Background technology]

[0002] Patent Document 1 discloses an oxide film removal method for removing a native oxide film formed on the surface of silicon at the bottom of a pattern such as a contact hole, trench, etc. Patent Document 1 also discloses a contact formation method for forming a contact at the bottom of the pattern by depositing a metal film after removing the native oxide film and reacting the silicon at the bottom of the pattern with the metal film. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2018-148193 Summary of the Invention [Problem to be solved by the invention]

[0004] One aspect of the present disclosure provides a silicon film forming method and a silicon film forming system for selectively depositing a silicon film on the bottom of a recess in a substrate having a recess. [Means for solving the problem]

[0005] A substrate processing method according to one aspect of the present disclosure includes the steps of: preparing a substrate having a base portion having an epitaxial layer formed by epitaxial growth; and an insulating film formed on the base portion and having a through portion exposing the epitaxial layer; and selectively forming a silicon film on a surface of the epitaxial layer exposed from the through portion rather than on a side wall of the through portion, the step of selectively forming the silicon film including: supplying a silicon-containing gas to form a silicon film; and supplying a halogen-containing gas to remove the silicon film formed on the side wall of the through portion, wherein in the step of forming the silicon film, the silicon film formed on the bottom of the through portion is crystalline silicon and the silicon film formed on the side wall of the through portion is amorphous silicon, and in the step of removing the silicon film, the amorphous silicon formed on the side wall of the through portion is selectively removed. [Effects of the Invention]

[0006] According to one aspect of the present disclosure, it is possible to provide a silicon film forming method and a silicon film forming system for selectively forming a silicon film on the bottom of a recess in a substrate having a recess. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a schematic diagram illustrating an example of the configuration of a substrate processing system. [Figure 2] FIG. 1 is a schematic diagram illustrating an example of the configuration of a processing apparatus. [Figure 3] FIG. 1 is a schematic diagram illustrating an example of the configuration of a processing apparatus. [Figure 4] FIG. 1 is a schematic diagram illustrating an example of the configuration of a processing apparatus. [Figure 5] 10 is an example of a flowchart illustrating a substrate processing method of the substrate processing system. [Figure 6] 1A to 1C are cross-sectional views of a substrate in each step; [Figure 7] 10 is an example of a graph showing a result of forming a Si film in the process shown in step S104. [Figure 8] 1 is a graph showing an example of etching rates for an amorphous silicon film and a crystalline silicon film. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the drawings, the same or corresponding components are denoted by the same reference numerals, and descriptions thereof may be omitted.

[0009] [Substrate Processing System] A substrate processing system according to one embodiment will be described with reference to Fig. 1. Fig. 1 is a schematic diagram showing an example of the configuration of a substrate processing system.

[0010] As shown in FIG. 1, the substrate processing system includes processing devices 101 to 104, a vacuum transfer chamber 200, load lock chambers 301 to 303, an atmospheric transfer chamber 400, load ports 501 to 503, and a control unit 600.

[0011] The processing devices 101 to 104 are connected to the vacuum transfer chamber 200 via gate valves G11 to G14, respectively. The processing devices 101 to 104 are depressurized to a predetermined vacuum atmosphere, and a desired process is performed on a substrate W such as a wafer therein. The processing device 101 is a device that removes a native oxide film formed on the bottom of a recess in the substrate W. The processing device 102 is a device that selectively forms a silicon film (hereinafter also referred to as a Si film) on the bottom of a recess in the substrate W. The processing device 103 is a device that selectively forms a metal silicide film on the bottom of a recess in the substrate W by forming a metal film on the substrate W. The processing device 104 may be the same device as any of the processing devices 101 to 103, or may be a device that performs a different process. The processing devices 101 to 103 will be described later with reference to FIGS. 2 to 4.

[0012] The interior of the vacuum transfer chamber 200 is depressurized to a predetermined vacuum atmosphere. The vacuum transfer chamber 200 is provided with a transfer mechanism 201 capable of transferring a substrate W in a depressurized state. The transfer mechanism 201 transfers the substrate W to the processing devices 101 to 104 and the load lock chambers 301 to 303. The transfer mechanism 201 has, for example, two transfer arms 202a and 202b.

[0013] The load lock chambers 301 to 303 are connected to the vacuum transfer chamber 200 via gate valves G21 to G23, respectively, and are connected to the atmospheric transfer chamber 400 via gate valves G31 to G33. The interiors of the load lock chambers 301 to 303 can be switched between an atmospheric atmosphere and a vacuum atmosphere.

[0014] The atmosphere inside the atmospheric transfer chamber 400 is atmospheric, and for example, a downflow of clean air is formed. An aligner 401 that aligns the substrate W is provided inside the atmospheric transfer chamber 400. A transfer mechanism 402 is also provided in the atmospheric transfer chamber 400. The transfer mechanism 402 transfers the substrate W to the load lock chambers 301 to 303, carriers C of load ports 501 to 503 (described later), and the aligner 401.

[0015] The load ports 501 to 503 are provided on the long side wall surfaces of the atmospheric transfer chamber 400. Carriers C accommodating substrates W or empty carriers C are attached to the load ports 501 to 503. As the carriers C, for example, FOUPs (Front Opening Unified Pods) can be used.

[0016] The control unit 600 controls each unit of the substrate processing system. For example, the control unit 600 executes the operations of the processing devices 101 to 104, the operation of the transfer mechanisms 201 and 402, the opening and closing of the gate valves G11 to G14, G21 to G23, and G31 to G33, and the switching of the atmospheres in the load lock chambers 301 to 303. The control unit 600 may be, for example, a computer.

[0017] However, the configuration of the substrate processing system is not limited to this. The substrate processing system may be configured to have a multi-wafer processing apparatus that processes multiple substrates W in one processing apparatus, or the vacuum transfer chamber may be configured to be connected to the multi-wafer processing apparatus via a gate valve, or to be connected to multiple vacuum transfer apparatuses.

[0018] [Processing device 101] Next, the processing apparatus 101 will be described with reference to Fig. 2. Fig. 2 is a schematic diagram showing an example of the configuration of the processing apparatus 101. The processing apparatus 101 is an apparatus for removing a native oxide film formed on the bottom of a recess of a substrate W in a processing container 1 under reduced pressure.

[0019] As shown in FIG. 2, the processing apparatus 101 includes a processing chamber 1, a mounting table 2, a shower head 3, an exhaust unit 4, a gas supply mechanism 5, an RF power supply unit 8, and a control unit 9.

[0020] The processing vessel 1 is made of a metal such as aluminum and has a generally cylindrical shape. The processing vessel 1 accommodates a substrate W. A loading / unloading port 11 is formed in a sidewall of the processing vessel 1 for loading or unloading the substrate W. The loading / unloading port 11 is opened and closed by a gate valve 12 (gate valve G11 shown in FIG. 1 ). An annular exhaust duct 13 with a rectangular cross section is provided above the main body of the processing vessel 1. A slit 13a is formed along the inner circumferential surface of the exhaust duct 13. An exhaust port 13b is formed in the outer wall of the exhaust duct 13. A ceiling wall 14 is provided on the upper surface of the exhaust duct 13 to close the upper opening of the processing vessel 1 via an insulating member 16. A seal ring 15 hermetically seals the space between the exhaust duct 13 and the insulating member 16. A partition member 17 partitions the interior of the processing vessel 1 into upper and lower sections when the mounting table 2 (and cover member 22) is raised to a processing position described below.

[0021] The mounting table 2 supports the substrate W horizontally within the processing chamber 1. The mounting table 2 is formed in a disk shape corresponding to the size of the substrate W and is supported by a support member 23. The mounting table 2 is made of a ceramic material such as AlN or a metal material such as an aluminum or nickel alloy, and has a heater 21 embedded therein for heating the substrate W. The heater 21 generates heat when power is supplied from a heater power supply (not shown). The output of the heater 21 is controlled by a temperature signal from a thermocouple (not shown) installed near the top surface of the mounting table 2, thereby controlling the substrate W to a predetermined temperature. The mounting table 2 may be equipped with an electrostatic chuck for electrostatically attracting the substrate W. The provision of the electrostatic chuck electrostatically attracts the substrate W to the surface of the mounting table 2, allowing the temperature of the substrate W to be controlled with high precision. The mounting table 2 may also have an internal flow path through which a temperature-controlling coolant from an external source can be passed and circulated. The mounting table 2 is provided with a cover member 22 made of ceramics such as alumina so as to cover the outer peripheral region of the upper surface and the side surfaces.

[0022] A support member 23 that supports the mounting table 2 is provided on the bottom surface of the mounting table 2. The support member 23 extends from the center of the bottom surface of the mounting table 2 to below the processing vessel 1, passing through a hole formed in the bottom wall of the processing vessel 1, and its lower end is connected to a lifting mechanism 24. The lifting mechanism 24 raises and lowers the mounting table 2 via the support member 23 between a processing position shown in FIG. 1 and a transfer position shown by a two-dot chain line below the processing position where the substrate W can be transferred. A flange 25 is attached to the support member 23 below the processing vessel 1, and a bellows 26 that separates the atmosphere inside the processing vessel 1 from the outside air and expands and contracts as the mounting table 2 is raised and lowered is provided between the bottom surface of the processing vessel 1 and the flange 25.

[0023] Three substrate support pins 27 (only two are shown) are provided near the bottom surface of the processing vessel 1, protruding upward from a lifting plate 27a. The substrate support pins 27 are raised and lowered via the lifting plate 27a by a lifting mechanism 28 provided below the processing vessel 1. The substrate support pins 27 are inserted into through-holes 2a provided in the mounting table 2 at the transfer position, and are capable of projecting and retracting relative to the upper surface of the mounting table 2. By raising and lowering the substrate support pins 27, the substrate W is transferred between the transfer mechanism (not shown) and the mounting table 2.

[0024] The showerhead 3 supplies a processing gas into the processing vessel 1 in a shower-like manner. The showerhead 3 is made of metal and is disposed opposite the mounting table 2. It has approximately the same diameter as the mounting table 2. The showerhead 3 includes a main body 31 fixed to the ceiling wall 14 of the processing vessel 1 and a shower plate 32 connected below the main body 31. A gas diffusion space 33 is formed between the main body 31 and the shower plate 32. A gas inlet hole 36 is provided in the gas diffusion space 33, penetrating the center of the main body 31 and the ceiling wall 14 of the processing vessel 1. A downwardly protruding annular protrusion 34 is formed on the periphery of the shower plate 32. A gas outlet hole 35 is formed on the inner flat surface of the annular protrusion 34. When the mounting table 2 is in the processing position, a processing space 38 is formed between the mounting table 2 and the shower plate 32. The upper surface of the cover member 22 is adjacent to the annular protrusion 34, forming an annular gap 39.

[0025] The exhaust unit 4 exhausts the inside of the processing vessel 1. The exhaust unit 4 has an exhaust pipe 41 connected to the exhaust port 13b and an exhaust mechanism 42 having a vacuum pump, a pressure control valve, etc. connected to the exhaust pipe 41. During processing, gas inside the processing vessel 1 reaches the exhaust duct 13 through the slit 13a, passes from the exhaust duct 13 through the exhaust pipe 41, and is exhausted by the exhaust mechanism 42.

[0026] The gas supply mechanism 5 supplies a processing gas into the processing chamber 1. The gas supply mechanism 5 includes a gas supply unit 50a.

[0027] The gas supply unit 50a supplies an etching gas through a gas supply line 50b into the processing chamber 1. The etching gas supplied into the processing chamber 1 may be a halogen-containing gas (e.g., C4F8 gas, HF gas, or CF4 gas), NH3 gas, H2 gas, an inert gas, or the like.

[0028] A flow rate controller 50c and a valve 50d are installed in the gas supply line 50b from the upstream side. The downstream side of the valve 50d of the gas supply line 50b is connected to the gas inlet hole 36. The gas supplied from the gas supply unit 50a is supplied into the processing vessel 1. The supply of gas from the gas supply unit 50a to the processing vessel 1 is started and stopped by opening and closing the valve 50d.

[0029] The processing apparatus 101 is a capacitively coupled plasma apparatus, in which the mounting table 2 serves as a lower electrode and the shower head 3 serves as an upper electrode. The mounting table 2 serving as the lower electrode is grounded via a capacitor (not shown).

[0030] The showerhead 3 serving as the upper electrode receives high-frequency power (hereinafter also referred to as "RF power") from an RF power supply unit 8. The RF power supply unit 8 includes a power feed line 81, a matching box 82, and a high-frequency power supply 83. The high-frequency power supply 83 is a power supply that generates high-frequency power. The high-frequency power has a frequency suitable for generating plasma. The frequency of the high-frequency power is, for example, within a range of 450 KHz to 100 MHz. The high-frequency power supply 83 is connected to the main body 31 of the showerhead 3 via the matching box 82 and the power feed line 81. The matching box 82 includes a circuit for matching the output reactance of the high-frequency power supply 83 with the reactance of the load (upper electrode). While the RF power supply unit 8 has been described as applying high-frequency power to the showerhead 3 serving as the upper electrode, the present invention is not limited to this. The RF power supply unit 8 may also be configured to apply high-frequency power to the mounting table 2 serving as the lower electrode.

[0031] The control unit 9 is, for example, a computer, and includes a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), an auxiliary storage device, etc. The CPU operates based on a program stored in the ROM or the auxiliary storage device, and controls the operation of the processing device 101. The control unit 9 may be provided inside or outside the processing device 101. When the control unit 9 is provided outside the processing device 101, the control unit 9 can control the processing device 101 via communication means such as wired or wireless.

[0032] [Processing device 102] Next, the processing apparatus 102 will be described with reference to Fig. 3. Fig. 3 is a schematic diagram showing an example of the configuration of the processing apparatus 102. The processing apparatus 102 is an apparatus that selectively forms a Si film on the bottom of a recess in a substrate W within a processing container 1 that is in a reduced pressure state.

[0033] 3, the processing apparatus 102 includes a processing vessel 1, a mounting table 2, a shower head 3, an exhaust unit 4, a gas supply mechanism 5, and a control unit 9. Note that, in the processing apparatus 102, the description of the components that overlap with those of the processing apparatus 101 (see FIG. 2) will be omitted.

[0034] The gas supply mechanism 5 supplies a processing gas into the processing chamber 1. The gas supply mechanism 5 includes a silicon-containing gas supply unit 51a, a halogen-containing gas supply unit 52a, and an inert gas supply unit 55a.

[0035] The silicon-containing gas supply unit 51a supplies a silicon-containing gas into the processing chamber 1 through a gas supply line 51b. Examples of the silicon-containing gas include SiH4 gas, Si2H6 gas, SiH2Cl2 gas, Si3H8 gas, and Si4H 10 The gas may include at least one of the following gases:

[0036] A flow rate controller 51c and a valve 51d are provided in the gas supply line 51b from the upstream side. The downstream side of the valve 51d of the gas supply line 51b is connected to the gas inlet hole 36 via a gas supply line 57. The silicon-containing gas supplied from the silicon-containing gas supply unit 51a is supplied into the processing chamber 1. The supply of the silicon-containing gas from the silicon-containing gas supply unit 51a to the processing chamber 1 is started and stopped by opening and closing the valve 51d.

[0037] The halogen-containing gas supply unit 52a supplies a halogen-containing gas through the gas supply line 52b into the processing chamber 1. As the halogen-containing gas, for example, a gas containing at least one of Cl gas, HBr gas, ClF gas, etc. can be used.

[0038] A flow rate controller 52c and a valve 52d are provided on the gas supply line 52b from the upstream side. The downstream side of the valve 52d on the gas supply line 52b is connected to the gas inlet hole 36 via a gas supply line 57. The halogen-containing gas supplied from the halogen-containing gas supply unit 52a is supplied into the processing vessel 1. The supply of the halogen-containing gas from the halogen-containing gas supply unit 52a to the processing vessel 1 is started and stopped by opening and closing the valve 52d.

[0039] The inert gas supply unit 55a supplies an inert gas through a gas supply line 55b into the processing chamber 1. As the inert gas, for example, Ar gas or the like can be used.

[0040] A flow rate controller 55c and a valve 55d are provided in the gas supply line 55b from the upstream side. The downstream side of the valve 55d of the gas supply line 55b is connected to the gas inlet hole 36 via a gas supply line 57. The inert gas supplied from the inert gas supply unit 55a is supplied into the processing vessel 1. The supply of the inert gas from the inert gas supply unit 55a to the processing vessel 1 is started and stopped by opening and closing the valve 55d.

[0041] [Processing device 103] Next, the processing apparatus 103 will be described with reference to Fig. 4. Fig. 4 is a schematic diagram showing an example of the configuration of the processing apparatus 103. The processing apparatus 103 is an apparatus that forms a metal film on the substrate W in a processing container 1 that is in a reduced pressure state. By forming the metal film, a metal silicide film is selectively formed on the bottom of a recess in the substrate W.

[0042] 4, the processing apparatus 103 includes a processing vessel 1, a mounting table 2, a shower head 3, an exhaust unit 4, a gas supply mechanism 5, an RF power supply unit 8, and a control unit 9. Note that, in the processing apparatus 102, the description of the components that overlap with those of the processing apparatus 101 (see FIG. 2) will be omitted.

[0043] The gas supply mechanism 5 supplies a processing gas into the processing chamber 1. The gas supply mechanism 5 includes a metal-containing gas supply unit 53a, a reducing gas supply unit 54a, and an inert gas supply unit 56a.

[0044] The metal-containing gas supply unit 53a supplies a metal-containing gas through the gas supply line 53b into the processing chamber 1. As the metal-containing gas, for example, a gas containing at least one of TiCl4 gas, TiBr4 gas, etc. can be used.

[0045] A flow rate controller 53c and a valve 53d are provided in the gas supply line 53b from the upstream side. The downstream side of the valve 53d of the gas supply line 53b is connected to the gas inlet hole 36 via a gas supply line 57. The metal-containing gas supplied from the metal-containing gas supply unit 53a is supplied into the processing vessel 1. The supply of the metal-containing gas from the metal-containing gas supply unit 53a to the processing vessel 1 is started and stopped by opening and closing the valve 53d.

[0046] The reducing gas supply unit 54a supplies a reducing gas through a gas supply line 54b into the processing chamber 1. As the reducing gas, for example, H2 gas or the like can be used.

[0047] A flow rate controller 54c and a valve 54d are provided on the gas supply line 54b from the upstream side. The downstream side of the valve 54d on the gas supply line 54b is connected to the gas inlet hole 36 via a gas supply line 57. The reducing gas supplied from the reducing gas supply unit 54a is supplied into the processing chamber 1. The supply of the reducing gas from the reducing gas supply unit 54a to the processing chamber 1 is started and stopped by opening and closing the valve 54d.

[0048] The inert gas supply unit 56a supplies an inert gas through a gas supply line 56b into the processing chamber 1. As the inert gas, for example, Ar gas or the like can be used.

[0049] A flow rate controller 56c and a valve 56d are provided on the gas supply line 56b from the upstream side. The downstream side of the valve 56d on the gas supply line 56b is connected to the gas inlet 36 via a gas supply line 57. The inert gas supplied from the inert gas supply unit 56a is supplied into the processing vessel 1. The supply of the inert gas from the inert gas supply unit 56a to the processing vessel 1 is started and stopped by opening and closing the valve 56d.

[0050] [Substrate Processing Method] Next, a substrate processing method of a substrate processing system according to one embodiment will be described with reference to Figures 5 and 6. Figure 5 is an example of a flowchart illustrating the substrate processing method of the substrate processing system. Figure 6 is an example of a cross-sectional view of a substrate W in each step.

[0051] In step S101, the control unit 600 prepares a substrate W. The control unit 600 controls the transfer mechanism 402 and the gate valve G31 to transfer the substrate W accommodated in the carrier C through the atmospheric transfer chamber 400 to the load lock chamber 301, which is in an atmospheric atmosphere. The control unit 600 controls the load lock chamber 301 to reduce the pressure inside the load lock chamber 301 to a vacuum atmosphere. The control unit 600 controls the transfer mechanism 201 and the gate valves G21 and G11 to transfer the substrate W from the load lock chamber 301 to the processing apparatus 101 and place the substrate W on the mounting table 2 of the processing apparatus 101. The control unit 9 of the processing apparatus 101 then controls the lifting mechanism 24 to raise the mounting table 2 from the transfer position to the processing position.

[0052] 6(a) shows an example of a prepared substrate W. The substrate W has a base portion 700 and an insulating film 710 formed on the base portion 700. The base portion 700 is made of, for example, Si or SiGe. The insulating film 710 is made of, for example, SiN or SiO2. A through portion 720 is formed in the insulating film 710 so as to expose the surface of the base portion 700. That is, a recess is formed in the surface of the substrate W, and the surface of the base portion 700 is exposed at the bottom of the recess.

[0053] The base portion 700 has an epitaxial layer 701, which is a crystalline silicon film formed by epitaxial growth. For example, in a fin-channel field-effect transistor, the source and drain are formed by epitaxially growing Si or SiGe. In addition, a native oxide film 702 is formed on the surface of the base portion 700 exposed from the through portion 720 (the bottom of the recess).

[0054] In step S102, the control unit 600 controls the processing device 101 to remove the native oxide film 702 formed on the surface of the base portion 700 exposed from the through portion 720.

[0055] The processing apparatus 101 applies high frequency power to the shower head 3 serving as the upper electrode by the RF power supply unit 8, and supplies an etching gas (e.g., C4F8 gas), an inert gas, etc. from the gas supply unit 50a into the processing chamber 1, thereby performing plasma etching to remove the native oxide film 702 on the substrate W. The processing apparatus 101 also supplies an etching gas (e.g., HF gas) and a reactive gas (e.g., NH3 gas) from the gas supply unit 50a into the processing chamber 1, thereby performing chemical etching to remove the native oxide film 702 on the substrate W. Note that the method for removing the native oxide film 702 performed in the processing apparatus 101 is not limited to these.

[0056] 6(b) shows an example of the substrate W from which the native oxide film 702 has been removed. By removing the native oxide film 702, the surface of the base portion 700 exposed from the through portion 720 exposes the surface of the epitaxial layer 701, which is a crystalline silicon film.

[0057] In step S103, the control unit 600 vacuum-transfers the substrate W from the processing apparatus 101 to the processing apparatus 102. The control unit 9 of the processing apparatus 101 controls the lifting mechanism 24 to lower the mounting table 2 from the processing position to the transfer position. The control unit 600 controls the transfer mechanism 201 and gate valves G11 and G12 to transport the substrate W from the processing apparatus 101 to the processing apparatus 102 and place the substrate W on the mounting table 2 of the processing apparatus 102. Then, the control unit 9 of the processing apparatus 102 controls the lifting mechanism 24 to raise the mounting table 2 from the transfer position to the processing position.

[0058] In step S104, the control unit 600 controls the processing device 102 to form a Si film on the substrate W.

[0059] The processing apparatus 102 supplies a silicon-containing gas (e.g., monosilane (SiH4) gas, disilane (Si2H6) gas, trisilane (Si3H8) gas, tetrasilane (Si4H) gas, etc.) from a silicon-containing gas supply unit 51a into the processing chamber 1. 10A Si film is formed on the substrate W by supplying a chlorine-containing compound gas such as monochlorosilane (SiH3Cl) gas, dichlorosilane (SiH2Cl2) gas, trichlorosilane (SiHCl3) gas, silicon tetrachloride (SiCl4) gas, or hexachlorodisilane (Si2Cl6) gas.

[0060] Here, FIG. 6(c) shows an example of a substrate W on which a Si film has been formed by processing in the processing apparatus 102.

[0061] An epitaxial layer 701 made of Si or SiGe is formed on the bottom of the recess. Therefore, a crystalline silicon film is formed on the bottom of the recess by epitaxial growth from the epitaxial layer 701. This allows the thickness of the epitaxial layer 701 to be increased. Meanwhile, an amorphous silicon film 703 is formed on the upper surface of the insulating film 710 made of SiN or SiO2 and on the side wall of the through hole 720. In this way, due to the difference in the base on which the Si film is formed, a crystalline silicon film (epitaxial layer 701) can be formed on the bottom of the recess, and an amorphous silicon film 703 can be formed on the side and upper surface of the recess.

[0062] 7A and 7B are graphs showing examples of the results of forming a Si film in step S104. Fig. 7A shows the case where a Si film was formed on a Si substrate, and Fig. 7B shows the case where a Si film was formed on a SiGe substrate. EDX analysis was performed with the horizontal axis representing depth (nm) and the vertical axis representing element concentration (At%) to confirm whether a Si film was formed.

[0063] The Si film was formed under the following film forming conditions: a stage temperature of 500 to 600° C., a pressure of 1 to 10 Torr, Si2H6 gas of 10 to 100 sccm as the silicon-containing gas, and Ar gas of 100 to 5000 sccm as the inert gas.

[0064] From the results shown in Figures 7(a) and 7(b), it was confirmed that Si films could be formed on both Si and SiGe substrates.

[0065] When Si2H6 gas is used as the silicon-containing gas, the temperature of the substrate W during the formation of the Si film is controlled to 400°C to 580°C, whereby a crystalline silicon film is formed on the surface (bottom of the recess) of the epitaxial layer 701, and an amorphous silicon film is formed on the upper surface of the insulating film 710 and the sidewall of the through-hole 720 (sidewall of the recess). 10 When gas is used, by controlling the temperature of the substrate W to 350°C to 480°C, a crystalline silicon film is formed on the surface of the epitaxial layer 701 (the bottom of the recess), and an amorphous silicon film is formed on the upper surface of the insulating film 710 and the side wall of the through portion 720 (the side wall of the recess).

[0066] Returning to FIGS. 5 and 6, in step S105, the control unit 600 controls the processing device 102 to selectively etch the amorphous silicon film 703.

[0067] The processing apparatus 102 chemically etches the Si film formed on the substrate W by, for example, supplying a halogen-containing gas (for example, Cl2 gas, HBr gas, or ClF3 gas) into the processing chamber 1 from the halogen-containing gas supply unit 52a.

[0068] Here, the etching rates of amorphous silicon films and crystalline silicon films will be explained using FIG. 8. FIG. 8 is a graph showing an example of the etching rates for amorphous silicon films and crystalline silicon films. The horizontal axis represents the reciprocal of temperature, 1000 / T [1 / °C]. The vertical axis represents the etching rate [nm / min]. The etching rate for the amorphous silicon film (a-Si) is shown by a solid line, and the etching rate for the crystalline silicon film (Epi Si) is shown by a dashed line.

[0069] Here, the amorphous silicon film and the crystalline silicon film were chemically etched using Cl gas as the halogen-containing gas. In the example shown in the graph of Figure 8, the etching rate for the amorphous silicon film is about 10 times that for the crystalline silicon film. This allows the processing device 102 to selectively etch the amorphous silicon film 703.

[0070] 6(d) shows an example of the substrate W in which the amorphous silicon film 703 has been selectively etched by the processing of the processing device 102. The amorphous silicon film 703 formed on the upper surface of the insulating film 710 and the side wall of the through portion 720 is etched.

[0071] In this way, by the processes of steps S104 and S105, a crystalline silicon film can be selectively formed on the bottom of the recess.

[0072] Although the process of supplying a silicon-containing gas in step S104 and the process of supplying a halogen-containing gas in step S105 have been described as being performed in sequence, the present invention is not limited to this.

[0073] For example, a silicon-containing gas and a halogen-containing gas may be supplied simultaneously, which prevents the amorphous silicon film 703 from being formed on the upper surface of the insulating film 710 and the sidewall of the through-hole 720, and allows the crystalline silicon film (epitaxial layer 701) to be formed on the bottom of the recess.

[0074] Alternatively, the process of supplying a silicon-containing gas in step S104 and the process of supplying a halogen-containing gas in step S105 may be repeated, thereby forming a crystalline silicon film selectively on the bottom of the recess.

[0075] In step S106, the control unit 600 vacuum-transfers the substrate W from the processing apparatus 102 to the processing apparatus 103. The control unit 9 of the processing apparatus 102 controls the lifting mechanism 24 to lower the mounting table 2 from the processing position to the transfer position. The control unit 600 controls the transfer mechanism 201 and gate valves G12 and G13 to transport the substrate W from the processing apparatus 102 to the processing apparatus 103 and place the substrate W on the mounting table 2 of the processing apparatus 103. Then, the control unit 9 of the processing apparatus 103 controls the lifting mechanism 24 to raise the mounting table 2 from the transfer position to the processing position.

[0076] In step S107, the control unit 600 controls the processing device 103 to form a metal film (Ti film) on the substrate W.

[0077] The processing apparatus 103 supplies, for example, a metal-containing gas (e.g., TiCl4 gas, TiBr4 gas) into the processing vessel 1 from the metal-containing gas supply unit 53a, a reducing gas (e.g., H2 gas) into the processing vessel 1 from the reducing gas supply unit 54a, and an inert gas (e.g., Ar gas) into the processing vessel 1 from the inert gas supply unit 56a. Then, the RF power supply unit 8 applies high frequency power to the shower head 3 serving as the upper electrode to generate plasma, and the substrate W is exposed to the generated plasma to form a metal film (Ti film) on the substrate W by a CVD (chemical vapor deposition) reaction.

[0078] Here, at the bottom of the recess, a metal film (for example, a Ti film) is formed on the epitaxial layer 701. The metal film reacts with the epitaxial layer 701 to form a metal silicide film (TiSi film) 730 in a self-aligned manner.

[0079] Furthermore, the metal film (Ti film) formed on the upper surface of the insulating film 710 and the sidewall of the through portion 720 is self-etched by the TiCl gas. This prevents the metal film (Ti film) from being formed on the upper surface of the insulating film 710 and the sidewall of the through portion 720.

[0080] Although the metal film is a Ti film and the metal silicide film is a TiSi film in the above description, the present invention is not limited to this.

[0081] After the processing is completed, the control unit 600 vacuum-transfers the substrate W from the processing device 103 to the load lock chamber 301. The control unit 9 of the processing device 103 controls the lifting mechanism 24 to lower the mounting table 2 from the processing position to the transfer position. The control unit 600 controls the transfer mechanism 201 and gate valves G13 and G21 to transfer the substrate W from the processing device 103 to the load lock chamber 301. The control unit 600 controls the load lock chamber 301 to create an atmospheric atmosphere inside the load lock chamber 301. The control unit 600 controls the transfer mechanism 402 and gate valve G31 to transfer the substrate W from the load lock chamber 301 to the carrier C via the atmospheric transfer chamber 400, and stores the substrate W in the carrier C.

[0082] According to the substrate processing method of the substrate processing system of one embodiment, in a substrate W having a recess, a metal silicide film 730 can be selectively formed on the bottom of the recess. Furthermore, according to the substrate processing method of the substrate processing system, the amorphous silicon film 703 formed on the upper surface of the insulating film 710 and the sidewall of the through-hole 720 can be removed by the process of step S105. This makes it possible to prevent the metal silicide film from being formed on the upper surface of the insulating film 710 and the sidewall of the through-hole 720 when a metal film is formed on the substrate W by the process of step S107. Furthermore, the metal silicide film 730 can be suitably formed even on the bottom of a recess with a high aspect ratio.

[0083] Furthermore, according to the substrate processing method of the substrate processing system, the thickness of the crystalline silicon film (epitaxial layer 701) formed on the bottom of the recess can be increased by the processes of steps S104 and S105. As a result, the thickness of the metal silicide film 730 formed by the reaction between the metal film and the crystalline silicon film (epitaxial layer 701) can be increased by the process of step S107.

[0084] In this way, according to the substrate processing method of the substrate processing system, it is possible to increase the film thickness of the metal silicide film 730 formed on the bottom of the recess of the substrate W, and to prevent the metal silicide film from being formed on the upper surface of the insulating film 710 and the side wall of the through portion 720.

[0085] Furthermore, for example, when the epitaxial layer 701 is the source / drain of a fin-channel field-effect transistor, a contact that is a metal silicide film 730 can be selectively formed at the bottom of the recess, and the film thickness can be controlled (increased).

[0086] Furthermore, this embodiment can also be applied to a structure having a recess in the lateral direction or a structure having a through portion, such as a gate-all-around type field effect transistor.

[0087] Although the embodiment in which the Si film is formed without using plasma has been described, this is not limiting. For example, the RF power supply unit 8 of the processing device 101 may be applied to the processing device 102 to form the Si film using capacitively coupled plasma. Furthermore, the present invention is not limited to capacitively coupled plasma, and other applicable plasmas include inductively coupled plasma (ICP), microwave-excited surface wave plasma (SWP), electron cyclotron resonance plasma (ECP), and helicon wave-excited plasma (HWP).

[0088] Furthermore, even in the case where the materials of the base portion 700 are mixed, such as when the bottom of one of the multiple recesses is Si and the bottom of the other recess is SiGe, a crystalline silicon film can be selectively formed on the bottom of each recess, and the formed crystalline silicon film can be reacted with a metal film, thereby suppressing the variation in film thickness of the metal silicide film 730.

[0089] The above describes embodiments of the substrate processing system, but the present disclosure is not limited to the above embodiments, and various modifications and improvements are possible within the scope of the gist of the present disclosure as described in the claims. [Explanation of symbols]

[0090] 101 Processing device (first processing device) 102 Processing device (second processing device) 103 Processing device (third processing device) 200 Vacuum transfer chamber 201 Transport mechanism 600 control section 700 Base 701 Epitaxial layer (silicon film, crystalline silicon film) 702 Natural oxide film 703 Amorphous silicon film 710 insulating film 720 Penetration 730 Metal silicide film W substrate

Claims

1. a step of preparing a substrate having an underlayer having an epitaxial layer formed by epitaxial growth, and an insulating film formed on the underlayer and having a through portion exposing the epitaxial layer; selectively forming a silicon film on a surface of the epitaxial layer exposed from the through-hole rather than on a side wall of the through-hole; The step of selectively forming a silicon film includes: supplying a silicon-containing gas to form a silicon film; and a step of supplying a halogen-containing gas to remove the silicon film formed on the side wall of the through portion, in the step of forming the silicon film, the silicon film formed on the bottom of the through portion is crystalline silicon, and the silicon film formed on the side wall of the through portion is amorphous silicon; In the step of removing the silicon film, the amorphous silicon formed on the side wall of the through portion is selectively removed. A method for forming a silicon film.

2. a step of preparing a substrate having an underlayer having an epitaxial layer formed by epitaxial growth, and an insulating film formed on the underlayer and having a through portion exposing the epitaxial layer; selectively forming a silicon film on a surface of the epitaxial layer exposed from the through-hole rather than on a side wall of the through-hole; The step of selectively forming a silicon film includes: by simultaneously supplying a silicon-containing gas and a halogen-containing gas, amorphous silicon formed on the side wall of the through portion is removed, and crystalline silicon is selectively formed on the bottom of the through portion. A method for forming a silicon film.

3. The step of forming the silicon film includes: repeating the step of forming the silicon film and the step of removing the silicon film; The method for forming a silicon film according to claim 1 .

4. The silicon-containing gas is SiH ４ Gas, Si ２ H ６ Gas, SiH ２ Cl ２ Gas, Si ３ H ８ Gas, Si ４ H １０ at least one of the following gases: The halogen-containing gas is Cl ２ gas, HBr gas, ClF ３ at least one of the following gases: The method for forming a silicon film according to any one of claims 1 to 3.

5. The method further includes a step of depositing a metal film on the silicon film formed on the surface of the epitaxial layer from the sidewall of the through-hole, and reacting the silicon film with the metal film to form a metal silicide film. The method for forming a silicon film according to any one of claims 1 to 4.

6. The step of depositing the metal film and forming the metal silicide film includes: a step of supplying a metal-containing gas and a reducing gas to generate plasma, and exposing the substrate to the plasma to form the metal film; The method for forming a silicon film according to claim 5 .

7. The metal-containing gas is TiCl ４ Gas, TiBr ４ at least one of the following gases: The reducing gas is H ２ at least one of the following gases: The method for forming a silicon film according to claim 6 .

8. The insulating film is made of SiN or SiO ２ and the epitaxial layer comprises Si or SiGe; The method for forming a silicon film according to any one of claims 1 to 7.

9. Before the step of selectively forming the silicon film, removing an oxide film formed on a surface of the epitaxial layer exposed from the through portion; The method for forming a silicon film according to any one of claims 1 to 8.

10. the step of removing the oxide film, the step of selectively forming the silicon film, the step of forming the metal film, and the step of forming the metal silicide film are performed without breaking vacuum; The method for forming a silicon film according to claim 9 .

11. a first processing apparatus for removing an oxide film formed on a surface of the epitaxial layer exposed from the through-portion of a substrate having an underlayer having an epitaxial layer formed by epitaxial growth and an insulating film formed on the underlayer and having a through-portion exposing the epitaxial layer; a second processing apparatus for selectively forming a silicon film on a surface of the epitaxial layer exposed from the through-hole rather than on a side wall of the through-hole; The second processing device includes: supplying a silicon-containing gas to form a silicon film; a step of supplying a halogen-containing gas to remove the silicon film formed on the side wall of the through-hole, in the step of forming the silicon film, the silicon film formed on the bottom of the through portion is crystalline silicon, and the silicon film formed on the side wall of the through portion is amorphous silicon; In the step of removing the silicon film, the amorphous silicon formed on the side wall of the through portion is selectively removed. A system for forming a silicon film.

12. a first processing apparatus for removing an oxide film formed on a surface of the epitaxial layer exposed from the through-portion of a substrate having an underlayer having an epitaxial layer formed by epitaxial growth and an insulating film formed on the underlayer and having a through-portion exposing the epitaxial layer; a second processing apparatus for selectively forming a silicon film on a surface of the epitaxial layer exposed from the through-hole rather than on a side wall of the through-hole; The second processing device includes: by simultaneously supplying a silicon-containing gas and a halogen-containing gas, amorphous silicon formed on the side wall of the through portion is removed, and crystalline silicon is selectively formed on the bottom of the through portion. A system for forming a silicon film.

13. a third processing apparatus for depositing a metal film on the silicon film formed on the surface of the epitaxial layer closer to the sidewall of the through-hole, and reacting the silicon film with the metal film to form a metal silicide film; The system for forming the silicon film according to claim 11 or 12.

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