JP7529764B2 - Substrate processing apparatus, semiconductor device manufacturing method and program - Google Patents

Description

The present disclosure relates to a substrate processing apparatus, a method for manufacturing a semiconductor device, and a program.

A substrate processing apparatus having a processing chamber capable of annealing a substrate is disclosed (see Patent Document 1).

JP 2019-169663 A

In semiconductor manufacturing, hydrogen annealing is performed on substrates under various pressures of hydrogen gas atmospheres, either using only hydrogen or mixtures of hydrogen with helium, nitrogen, or argon.

In processing equipment, ignition and combustion will occur when the conditions for combustible gas, combustion supporting gas, and ignition source are met. When processing with high concentration hydrogen gas under slightly reduced pressure or atmospheric pressure, if the gas in the processing chamber ignites for some reason, the gas in the processing chamber will expand and the inside of the processing chamber will be pressurized. Under reduced pressure, it is easy to take measures so that the pressure limit is not exceeded when the gas expands, but to process under slightly reduced pressure or atmospheric pressure, sufficient safety measures are essential, such as making the entire processing chamber highly pressure-resistant.

Reducing the volume of the processing chamber and processing substrates in a small area reduces the area requiring safety measures, making it easier to deal with the problem; however, depending on the equipment configuration, there may not be enough space to transport substrates, making access difficult.

The present disclosure aims to facilitate processing of substrates using high concentration hydrogen gas under slightly reduced pressure or atmospheric pressure.

A substrate processing apparatus according to the present disclosure includes a substrate holding stage that can be raised and lowered inside a processing vessel, a processing space between an upper surface of the substrate holding stage in an elevated state and an opposing surface to the upper surface, and a shielding wall that surrounds the outer periphery of the substrate holding stage in an elevated state, a processing gas supply port that supplies a processing gas including hydrogen gas to the processing space, an inert gas supply port that supplies an inert gas to a space between the shielding wall and an inner wall of the processing vessel, a gas mixing section in which the processing gas discharged from the processing space is mixed with the inert gas inside the processing vessel, and a processing gas flow path that is formed between the outer periphery of the substrate holding stage in an elevated state and the inner periphery of the shielding wall, and is configured so that the processing gas flows from the processing space toward the gas mixing section .

The present disclosure makes it easy to process substrates using high concentration hydrogen gas under slightly reduced pressure or atmospheric pressure.

4 is a cross-sectional view showing a state in which the substrate holding table is lowered in the substrate processing apparatus according to the first embodiment. FIG. 4 is a cross-sectional view showing a state in which the substrate holding table is elevated in the substrate processing apparatus according to the first embodiment. FIG. 4 is an enlarged cross-sectional view showing flows of a processing gas and an inert gas during hydrogen annealing in the substrate processing apparatus according to the first embodiment. FIG. 10 is a cross-sectional view showing another example of the inert gas supply port in the substrate processing apparatus according to the first embodiment. FIG. FIG. 2 is a schematic configuration diagram of a controller of the substrate processing apparatus. FIG. 1 is a flow diagram of a substrate processing process. 10 is an enlarged cross-sectional view showing another example of the shower head in the substrate processing apparatus according to the first embodiment. FIG. FIG. 11 is a cross-sectional view showing a state in which the substrate holding table is lowered in the substrate processing apparatus according to the second embodiment. FIG. 11 is a cross-sectional view showing a state in which the substrate holding table is elevated in the substrate processing apparatus according to the second embodiment. 11 is an enlarged cross-sectional view showing flows of a processing gas and an inert gas during a hydrogen annealing process in the substrate processing apparatus according to a second embodiment. FIG.

Below, a description will be given of a form for implementing the present disclosure with reference to the drawings. In each drawing, the same or equivalent components and parts are given the same reference symbols. Furthermore, the dimensional ratios of the drawings have been exaggerated for the convenience of explanation and may differ from the actual ratios. Furthermore, the upward direction of the drawing will be described as the upper side or upper part, and the downward direction will be described as the lower side or lower part. Furthermore, all pressures described in this embodiment refer to atmospheric pressure.

[First embodiment]
1 and 2, a process for manufacturing a semiconductor device is performed in a substrate processing apparatus 10 according to this embodiment. The substrate processing apparatus 10 has a substrate holding table 12, a shielding wall 14, a process gas supply port 16, an inert gas supply port 18, and a gas mixing section 22.

(Substrate holder)
The substrate holder 12 is, for example, a disk-shaped susceptor that is provided inside the processing vessel 24, i.e., in the processing chamber, and can be raised and lowered within the processing vessel 24. Here, the processing vessel 24 is, for example, configured as a flat sealed vessel with a circular cross section. The processing vessel 24 is also configured of, for example, a metal material such as aluminum (Al) or stainless steel (SUS), or quartz. A transfer space 26 for transferring the substrate 30 is formed within the processing vessel 24. Also, as described later, a processing space 32 for processing a silicon wafer or the like as the substrate 30 is formed within the processing vessel 24 when the substrate holder 12 is raised. The processing vessel 24 is configured of an upper vessel 24a and a lower vessel 24b. A substrate loading/unloading port 24d adjacent to a gate valve 34 is provided on the side of the lower vessel 24b. The substrate 30 is configured to move between the transfer space 26 in the lower vessel 24b and a vacuum transfer chamber (not shown) via the substrate loading/unloading port 24d. A plurality of lift pins 36 are provided on the bottom of the lower vessel 24b.

A mounting surface 38a on which the substrate 30 is placed is provided, for example, in a concave shape, on the upper surface 38 of the substrate holding table 12. An outer upper surface 38b on which the substrate 30 is not placed is provided radially outward of the mounting surface 38a. The mounting surface 38a is provided, for example, in a concave shape, on the upper surface 38 of the substrate holding table 12. In other words, the upper surface 38 of the substrate holding table 12 has the mounting surface 38a and the outer upper surface 38b.

When the substrate 30 is placed on the mounting surface 38a, the outer upper surface 38b is configured to be approximately flush with the upper surface of the substrate 30. As a result, the outer upper surface 38b makes it possible to make the amount of process gas supplied to the outer periphery of the substrate 30 closer to the amount of process gas supplied to the center of the substrate 30. A protruding portion 12c is provided on the lower portion of the outer periphery 12b of the substrate holding table 12. The protruding portion 12c is a portion that protrudes radially outward from the outer periphery 12b in a flange-like shape.

The substrate holding table 12 may be provided with a first heater 41 as a heating section. By providing the first heater 41, the substrate 30 can be heated, improving the quality of the film formed on the substrate 30. The first heater 41 is also connected to a temperature control section 40 and configured to be temperature controllable. The temperature control section 40 is configured to be capable of transmitting and receiving temperature data to a controller 44 (FIG. 9) described below via a signal line.

The substrate holding table 12 is provided with through holes 12a through which the lift pins 36 pass, at positions corresponding to the lift pins 36. The substrate holding table 12 may also be provided with a film thickness monitor (not shown) that measures the film thickness of the film formed on the substrate 30. In this case, the film thickness monitor is connected to the film thickness meter via a signal line. The film thickness value (film thickness data) generated by the film thickness meter is configured to be able to be transmitted and received to a controller 44 (FIG. 9) described below via the signal line.

The substrate holding table 12 is supported by, for example, a single shaft 46. The shaft 46 penetrates the bottom of the processing vessel 24 and is further connected to a lifting mechanism 48 outside the processing vessel 24. By operating the lifting mechanism 48 to raise and lower the shaft 46 and the substrate holding table 12, it is possible to raise and lower the substrate 30 placed on the placement surface 38a. The lower end of the shaft 46 is surrounded by a bellows 50, and the inside of the processing vessel 24 is kept airtight. The lifting mechanism 48 is configured to be able to transmit height data of the substrate holding table 12 to the controller 44 described below.

As shown in FIG. 1, when transporting the substrate 30, the substrate holding table 12 is lowered so that the loading surface 38a is at the position of the substrate loading/unloading opening 24d (i.e., the transport position), and when processing the substrate 30, as shown in FIG. 2, the substrate 30 is raised to a processing position within the processing vessel 24 (i.e., the processing position).

Specifically, when the substrate holder 12 descends to the transport position, the upper ends of the lift pins 36 protrude from the mounting surface 38a and push up the substrate 30 from below, supporting the substrate 30 in a state in which it is lifted to a position higher than the upper surface 38 of the substrate holder 12, specifically the outer upper surface 38b. When the substrate holder 12 ascends to the processing position, the lift pins 36 sink from the mounting surface 38a, and the mounting surface 38a supports the substrate 30 from below. Since the lift pins 36 come into direct contact with the substrate 30, it is preferable that they are made of a material such as quartz or alumina. The lift pins 36 may be provided with an elevation mechanism so that the substrate holder 12 and the lift pins 36 move relative to each other.

(Shielding wall)
2 and 3, the shielding wall 14 is provided as a portion surrounding the processing space 32 between the upper surface 38 of the substrate holding table 12 in the elevated state and an opposing surface 52 facing the upper surface 38, and the outer periphery 12b of the substrate holding table 12 in the elevated state. In reality, the substrate 30 is placed on the mounting surface 38a and processed, so that the processing space 32 is formed between the upper surface of the substrate 30 placed on the mounting surface 38a and the opposing surface 52 facing the upper surface.

The shielding wall 14 is provided, for example, integrally with the shower head 54 described later. Specifically, the shielding wall 14 is provided as a portion extending cylindrically downward from the radial outer end of the shower head 54. When the substrate holding table 12 is raised to the processing position, the shower head 54 including the shielding wall 14 does not contact the substrate 30 and the substrate holding table 12, and a processing space 32 is formed between the upper surface of the substrate 30 placed on the mounting surface 38a and the opposing surface 52 facing the upper surface. In addition, a processing gas flow path 56 is formed between the inner peripheral surface of the shielding wall 14 and the outer periphery 12b of the substrate holding table 12, and between the lower end of the shielding wall 14 and the overhanging portion 12c of the substrate holding table 12. The processing gas flow path 56 is a flow path that guides the processing gas containing hydrogen gas supplied to the processing space 32 out of the processing space 32 to a position where it merges with the inert gas. In other words, the processing gas flow path 56 connects the processing space 32 with a gas mixing section 22 (described later), and constitutes a flow path through which the processing gas flows from the processing space 32 toward the gas mixing section 22 .

In addition, when the substrate holding table 12 is raised to the processing position, the lower end position of the substrate holding table 12 is raised so that it is located at a height lower than the lower end of the shielding wall 14. In this embodiment, the substrate holding table 12 is raised so that the lower end position of the substrate holding table 12 is lower than the lower end of the shielding wall 14 by the total length of the height direction width (thickness) of the overhanging portion 12c and the width of the processing gas flow path 56 between the lower end of the shielding wall 14 and the overhanging portion 12c. By setting the positional relationship between the lower end of the substrate holding table 12 and the lower end of the shielding wall in this way when the substrate holding table 12 is raised to the processing position, the processing gas flowing out from the processing gas flow path 56 can be directly merged with the flow of inert gas supplied from the inert gas supply port 18 described later without stagnation inside the shielding wall 14.

(Processing gas supply port)
1 to 3, the process gas supply port 16 is a portion that supplies a process gas containing hydrogen gas to the process space 32. An MFC (Mass Flow Controller) 58 serving as a flow rate control device for the process gas and a process gas valve 60 serving as an opening/closing valve are connected to the process gas supply port 16. The MFC 58, the process gas valve 60, and the process gas supply port 16 constitute a process gas supply unit (process gas supply system).

The concentration of hydrogen gas in the processing gas in the processing space 32 is 4% or more. The concentration of hydrogen gas in the processing gas in this embodiment may be 100%. In this case, the flow rate of the inert gas supplied from the inert gas supply port 18 into the processing vessel 24 is 24 times or more that of the processing gas. This makes it possible to make the concentration of hydrogen gas in the gas mixing section 22 less than 4%.

By making the hydrogen gas concentration in the gas mixing section 22 less than 4%, even if hydrogen gas and oxygen are mixed, it is possible to prevent rapid combustion due to ignition of the hydrogen gas. In other words, by adopting the device configuration according to this embodiment, it is possible to prevent rapid combustion due to ignition even if the concentration of hydrogen gas in the processing gas supplied to the processing space 32 is 4% or more. If the concentration of hydrogen gas in the processing gas supplied to the processing space 32 is 100%, there is a higher possibility that hydrogen gas and oxygen will be mixed due to leakage of hydrogen gas, etc., so the adoption of the device configuration according to this embodiment is more preferable. Note that it is desirable for the concentration of hydrogen gas in the mixing section 22 to be as low as possible, if it is less than 4%, but since there is a practical limit to the flow rate of the inert gas required for dilution that can be supplied, it is appropriate to set it to a range of 0.1% or more.

The processing gas supply port 16 is formed in a tubular support shaft (shower head) 62 extending in the vertical direction. The support shaft (shower head) 62 penetrates the ceiling surface 24e of the processing vessel 24.

The processing gas supply port 16 is composed of one or more processing gas outlets 54a provided in the facing surface 52. Specifically, the processing gas supply port 16 is composed of a shower head 54. The shower head 54 is provided in the processing vessel 24 and is configured to disperse the processing gas supplied from the processing gas supply port 16 and supply it to the processing space 32. The shower head 54 can also be called a "gas dispersion section." In the shower head 54, a plurality of processing gas outlets 54a are provided in the facing surface 52 facing the upper surface 38 of the substrate holding table 12. The processing gas outlets 54a are arranged over the entire facing surface 52. If the portion where the processing gas outlets 54a are provided is called the porous plate 64, the lower surface of the porous plate 64 is the facing surface 52.

The shower head 54 has a perforated plate 64, a lid 66 located above the perforated plate 64, a spacer 65 sandwiched between the perforated plate 64 and the lid 66, and a buffer space 67 surrounded by the perforated plate 64, the lid 66, and the spacer 65. The lid 66 is provided with a second heater 42 for heating the processing gas. The shower head 54 is also disposed in the processing vessel 24, away from the ceiling surface 24e of the processing vessel 24. Specifically, the processing gas introduced from the processing gas supply port 16 is supplied to the buffer space 67 in the shower head 54, and is widely distributed and supplied from the buffer space 67 to the processing space 32 through the multiple processing gas ejection holes 54a of the perforated plate 64. The perforated plate 64 in the shower head 54 is made of a material such as quartz, alumina, stainless steel, or aluminum.

A gas guide (not shown) for forming a flow of the supplied gas may be provided in the buffer space 67. The gas guide is provided, for example, on the underside of the lid 66, and has a conical shape whose diameter increases from the point where the process gas supply port 16 opens into the buffer space 67 toward the bottom of the substrate 30.

(Inert gas supply port)
The inert gas supply port 18 is a portion for supplying an inert gas to a space between the shielding wall 14 and the inner wall 24c of the processing container 24. For example, nitrogen gas is used as the inert gas. An MFC 68 serving as a flow rate control device for the inert gas and an inert gas valve 70 are connected to the inert gas supply port 18. The MFC 68, the inert gas valve 70, and the inert gas supply port 18 constitute an inert gas supply unit (inert gas supply system).

The flow rate of the inert gas supplied into the processing vessel 24 from the inert gas supply port 18 is adjusted so that the concentration of hydrogen gas in the gas mixing section 22 is, for example, less than 4%.

As an example, the inert gas supply port 18 is provided at least toward the center of the ceiling surface 24e of the processing vessel 24, rather than directly above the outer edge of the shower head 54. Specifically, the inert gas supply port 18 is provided concentrically with the support shaft (shower head) 62 of the shower head 54, outside the support shaft (shower head) 62, at the center of the ceiling surface 24e of the processing vessel 24. In other words, the support shaft (shower head) 62 of the shower head 54 is inserted through the inert gas supply port 18.

In addition, the inert gas supply port 18 is provided outside the shielding wall 14 and inside the inner wall 24c within the processing vessel 24, at the position of the upper end 14a of the shielding wall 14 or at a position higher than the upper end.

The inert gas is supplied from the inert gas supply port 18 between the upper surface of the shower head 54 and the ceiling surface 24e of the processing vessel 24, and is configured to reach the space between the shielding wall 14 and the inner wall 24c of the processing vessel 24.

The arrangement of the inert gas supply ports 18 is not limited to the examples shown in Figures 1 to 3. As shown in Figure 4, the inert gas supply ports 18 may be provided in a circumferential direction along the outer edge of the shower head 54 on the ceiling surface 24e of the processing vessel 24. This circumferential direction refers to the circumferential direction of the shower head 54. The multiple inert gas supply ports 18 may be provided evenly in the circumferential direction, or may be provided unevenly in the circumferential direction.

(Gas mixing section)
2 and 3, the gas mixing section 22 is a portion where the processing gas leaving the processing space 32 is mixed with the inert gas. The processing gas containing hydrogen gas is diluted by being mixed with the inert gas. Specifically, in the space between the shielding wall 14 and the inner wall 24c of the processing vessel 24, the inert gas supplied from the inert gas supply port 18 flows from above to below. The processing gas leaves the processing space 32 and passes through the processing gas flow path 56 between the shielding wall 14 and the substrate holding table 12, where it merges with the inert gas and is mixed with the inert gas. That is, the space inside the processing vessel 24 below the merger of the processing gas and the inert gas serves as the gas mixing section 22.

(Exhaust section)
The substrate processing apparatus 10 according to the present disclosure further includes an exhaust section (exhaust system). The exhaust section is provided in, for example, the lower vessel 24b. Specifically, an exhaust port 74 for exhausting the atmosphere of the processing vessel 24 is provided in the inner wall 24c of the lower vessel 24b. An upstream end of an exhaust pipe 76 is connected to the exhaust port 74 from the outside of the processing vessel 24. As an example, the exhaust pipe 76 is provided with an APC (Auto Pressure Controller) 78 as a pressure regulator (pressure adjustment section), a vent valve 80 as an opening/closing valve, and a vacuum pump 82 as a vacuum exhaust device, in this order from the upstream side. The exhaust port 74, the exhaust pipe 76, the APC 78, and the vent valve 80 constitute the exhaust section. The exhaust section may further include a vacuum pump 82.

By controlling the APC 78 of the exhaust unit and the MFC 58 of the processing gas supply unit, the pressure in the processing space 32 is adjusted to be atmospheric pressure or slightly reduced pressure relative to atmospheric pressure. The slightly reduced pressure range is, for example, "220 Torr or more, but less than atmospheric pressure". This is a range in which the pressure in the processing space 32 may exceed atmospheric pressure if the volume of hydrogen gas at the upper limit of combustion concentration (75%) suddenly expands due to combustion. In other words, in such a pressure range, the device configuration according to this embodiment is useful for ensuring safety. The slightly reduced pressure range may also be, for example, "300 Torr or more, but less than atmospheric pressure". This is a range in which practical effects can be obtained by hydrogen annealing treatment of metal films and metal wiring formed on a substrate. Note that the pressure in the processing space 32 may be greater than atmospheric pressure, if necessary.

(Control Unit)
The substrate processing apparatus 10 according to the present disclosure has a controller 44 as a control unit, as shown in Fig. 5. The controller 44 is configured to control the gate valve 34, the lifting mechanism 48, the APC 78, the vacuum pump 82, the first heater 41, the second heater 42, the process gas valve 60, the inert gas valve 70, and the vent valve 80 through signal lines (not shown). Although not shown in Fig. 5, the controller 44 is also configured to control the MFC 58, the process gas valve 60, the MFC 68, and the inert gas valve 70 shown in Fig. 1.

5, the controller 44, which is a control unit (control means), is configured as a computer equipped with a CPU (Central Processing Unit) 84a, a RAM (Random Access Memory) 84b, a storage device 84c, and an I/O port 84d. The RAM 84b, the storage device 84c, and the I/O port 84d are configured to be able to exchange data with the CPU 84a via an internal bus 84e. An input/output device 86 configured as, for example, a touch panel or a display is connected to the controller 44.

The storage device 84c is composed of, for example, a flash memory, a HDD (Hard Disk Drive), etc. A control program for controlling the operation of the substrate processing device, a program recipe in which the procedures and conditions of the substrate processing described later are described, etc. are stored in a readable manner in the storage device 84c. The process recipe is a combination of procedures in the substrate processing process described later that are executed by the controller 44 to obtain a predetermined result, and functions as a program. Hereinafter, the program recipe and the control program are collectively referred to as simply a program. In addition, when the word program is used in this specification, it may include only the program recipe, only the control program, or both. In addition, the RAM 84b is configured as a memory area (work area) in which the programs and data read by the CPU 84a are temporarily stored.

The I/O port 84d is connected to the above-mentioned gate valve 34, lifting mechanism 48, APC 78, vacuum pump 82, first heater 41, second heater 42, process gas valve 60, inert gas valve 70, vent valve 80, MFC 58, process gas valve 60, MFC 68 and inert gas valve 70, etc.

The CPU 84a is configured to read and execute a control program from the storage device 84c, and to read a process recipe from the storage device 84c in response to an input of an operation command from the input/output device 86. The CPU 84a is configured to control, through the I/O port 84d and a signal line (not shown), the opening and closing operation of the gate valve 34, the lifting and lowering operation of the lifting mechanism 48, the opening and closing operation of the APC 78, the start and stop of the vacuum pump 82, the supply power adjustment operation (temperature adjustment operation) to the first heater 41 and the second heater 42, the opening and closing operation of the process gas valve 60, the inert gas valve 70, the vent valve 80, and the process gas valve 60, the flow rate adjustment operation of the various gases of the MFC 58 and the MFC 68, and the like, in accordance with the contents of the read process recipe.

The controller 44 can be configured by installing the above-mentioned program stored in an external storage device (e.g., 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, an optical magnetic disk such as an MO, or a semiconductor memory such as a USB memory or a memory card) 88 into a computer. The storage device 84c and the external storage device 88 are configured as computer-readable recording media. Hereinafter, these are collectively referred to as recording media. In this specification, when the term recording media is used, it may include only the storage device 84c alone, only the external storage device 88 alone, or both. Note that the means for supplying the program to the computer is not limited to supplying the program via the external storage device 88. For example, the program may be supplied without going through the external storage device 88 by using a communication means such as a network 90 (Internet or a dedicated line).

(Substrate processing process)
Next, a substrate processing process using the substrate processing apparatus 10 and the semiconductor device manufacturing method according to this embodiment will be described mainly with reference to Fig. 6. Fig. 6 is a flow chart showing the substrate processing process according to this embodiment.

In this substrate processing process, the metal film and metal wiring formed on the substrate are subjected to an annealing process (hydrogen annealing process) in an atmosphere containing hydrogen gas.

The method for manufacturing a semiconductor device according to this embodiment includes a substrate loading step S110 in which a substrate 30 is loaded into the processing vessel 24 of the substrate processing apparatus 10, a processing step S200 (S120-S140) in which a hydrogen annealing process is performed on the substrate 30, and a substrate unloading step S150 in which the substrate 30 is unloaded from the processing vessel 24. This substrate processing step is performed by the above-mentioned substrate processing apparatus 10 as one step in the manufacturing process of a semiconductor device such as a flash memory. In the following description, the operation of each part constituting the substrate processing apparatus 10 is controlled by a controller 44 shown in FIG. 5.

(Substrate loading process S110)
First, a substrate 30, such as a wafer, is loaded into the processing chamber 24. Specifically, the lift mechanism 48 lowers the substrate holder 12 to a transfer position for the substrate 30, and the substrate holder 12 is inserted into the through hole 12a of the substrate holder 12. The lift pins 36 are penetrated. As a result, the lift pins 36 are in a state of protruding a predetermined height from the upper surface 38 (specifically, the outer upper surface 38b) of the substrate holding table 12.

Next, the gate valve 34 is opened, and the substrate 30 is loaded from the vacuum transfer chamber adjacent to the processing vessel 24 into the processing vessel 24 through the substrate loading/unloading port 24d using a wafer transfer mechanism (not shown). The loaded substrate 30 is supported in a horizontal position on the lift pins 36 protruding from the surface of the substrate holding table 12. After the substrate 30 is loaded into the processing vessel 24, the wafer transfer mechanism is retracted outside the processing vessel 24, and the gate valve 34 is closed to seal the processing vessel 24. Then, the lift mechanism 48 raises the substrate holding table 12, so that the substrate 30 is placed (supported) on the upper surface 38 (specifically, the placement surface 38a) of the substrate holding table 12. In addition, a processing space 32 is formed between the upper surface 38 of the substrate holding table 12 and the facing surface 52 of the shower head 54.

(Heating and evacuation process S120)
Next, the temperature of the substrate 30 carried into the processing vessel 24 is increased. The first heater 41 is preheated, and the substrate 30 is held on the substrate holding table 12 in which the first heater 41 is embedded, thereby heating the substrate 30 to a predetermined value within a range of, for example, 150 to 750° C. Here, the substrate 30 is heated to a temperature of 600° C. During the temperature increase of the substrate 30, the inside of the processing vessel 24 is evacuated by the vacuum pump 82 via the exhaust pipe 76, and the pressure inside the processing vessel 24 is set to a predetermined value. The vacuum pump 82 is operated at least until the substrate unloading step S150 described later is completed.

In this specification, a numerical range such as "150 to 750°C" means that the lower and upper limits are included in the range. Thus, for example, "150 to 750°C" means "150°C or higher and 750°C or lower." The same applies to other numerical ranges.

(Reaction gas supply process S130)
Next, the supply of the process gas containing hydrogen and the supply of the inert gas are started as the reactive gas. Specifically, the process gas valve 60 is opened, and the supply of the process gas from the process gas supply port 16 to the process space 32 is started while controlling the flow rate by the MFC 58, and the inert gas valve 70 is opened, and the supply of the inert gas from the inert gas supply port 18 to the process vessel 24 is started while controlling the flow rate by the MFC 68. The process gas is dispersed by the shower head 54 and supplied to the process space 32. At this time, the process gas is heated to a predetermined temperature by the second heater 42 provided on the shower head 54. The inert gas enters the process vessel 24 from the inert gas supply port 18, passes between the ceiling surface 24e of the process vessel 24 and the lid 66 of the shower head 54, reaches the outer edge of the shower head 54, passes between the shield wall 14 and the inner wall 24c of the process vessel 24, and flows to the gas mixing section 22.

At this time, a process gas with a hydrogen gas concentration of 100% may be supplied to the process space 32. The concentration of hydrogen gas in the process gas in the process space 32 is, for example, 4% or more. On the other hand, the flow rate of the inert gas supplied from the inert gas supply port 18 into the process vessel 24 is adjusted so that the concentration of hydrogen gas in the gas mixing section 22 is less than 4%. At this time, the opening degree of the MFC 58 and the APC 78 is adjusted to control the supply flow rate of the process gas to the process space 32 and the exhaust inside the process vessel 24, so that the pressure in the process space 32 is adjusted to, for example, atmospheric pressure or a slightly reduced pressure relative to atmospheric pressure (for example, 300 Torr or more, less than atmospheric pressure). In this way, the supply of the process gas and the inert gas is continued while the inside of the process vessel 24 is appropriately exhausted.

The upper surface of the substrate 30 faces the processing space 32, and the metal film on the substrate 30 is subjected to hydrogen annealing processing using a processing gas containing hydrogen gas. As shown in Figures 2 and 3, the processing space 32 and the outer periphery 12b of the substrate holding table 12 are surrounded by a shielding wall 14 integrally provided on the shower head 54. In addition, an inert gas is supplied between the shielding wall 14 and the inner wall 24c of the processing vessel 24. As shown in Figure 3, the processing gas coming out of the processing space 32 passes through the processing gas flow path 56 between the shielding wall 14 and the substrate holding table 12, and merges with the inert gas after passing through the processing gas flow path 56, where it is mixed with the inert gas and reaches the gas mixing section 22 below.

In this way, even if the concentration of hydrogen gas is 4% or more in the processing space 32 under atmospheric pressure or slight reduced pressure, the surroundings of the processing space 32 are purged with inert gas and oxygen does not enter the processing space 32, so that rapid combustion of hydrogen gas is suppressed. Similarly, in the gas mixing section 22, which is under atmospheric pressure or slight reduced pressure, the processing gas is diluted with inert gas and the concentration of hydrogen gas is less than 4%, so that rapid combustion of hydrogen gas is suppressed. In addition, since the hydrogen annealing process of the substrate is performed in the narrow processing space 32, the range of safety measures is small and it is easy to deal with. Therefore, while securing the substrate transport space (i.e., the transport space 26), hydrogen annealing process of the substrate can be performed under slight reduced pressure or atmospheric pressure with minimum safety measures.

(Vacuum exhaust step S140)
When the hydrogen annealing process is completed, the supply of the process gas and the inert gas is stopped, and the inside of the process vessel 24 is evacuated to a vacuum via the exhaust pipe 76. This allows the process gas, the inert gas, and exhaust gas generated by the reaction of the gases in the process vessel 24 to be exhausted to the outside of the process vessel 24. Thereafter, the opening of the APC 78 is adjusted to adjust the pressure in the process vessel 24 to the same pressure as that of the vacuum transfer chamber adjacent to the process vessel 24 (i.e., the transfer destination of the substrate 30, not shown), for example, 100 Pa.

(Substrate unloading process S150)
When the pressure inside the processing vessel 24 reaches a predetermined level, the substrate holder 12 is lowered to the transfer position for the substrate 30, and the substrate 30 is supported on the lift pins 36. Then, the gate valve 34 is opened, and the substrate 30 is transferred to the processing vessel 24 using the wafer transfer mechanism. The substrate 30 is then transferred out of the processing chamber 24 through the substrate transfer port 24d. This completes the substrate processing process according to this embodiment.

(program)
The program used in the above-mentioned substrate processing process causes the substrate processing apparatus 10 to execute, via a computer, the steps of loading the substrate 30 into the processing vessel 24 and placing it on the substrate holding table 12, performing a hydrogen annealing process on the substrate 30, and unloading the substrate 30 from the processing vessel 24.

According to this embodiment, by limiting the space in which hydrogen gas rapidly expands when hydrogen gas burns, it is possible to reduce the cost required for measures to make the entire device high-pressure resistant and explosion-proof without having to take measures to make the entire device high-pressure resistant and explosion-proof, and to improve the safety performance of the device while facilitating operation.

In addition, according to this embodiment, the volume of the processing space 32 in which a high concentration of hydrogen gas exists can be minimized by the shielding wall 12 and the rising and lowering substrate holding table 12.

Furthermore, according to this embodiment, the high concentration hydrogen gas discharged from the processing space 32 is quickly diluted in the gas mixing section 22 to a concentration below the lower limit of combustion (4%), thereby minimizing the area other than the processing space 32 where sudden combustion may occur.

Furthermore, according to this embodiment, by supplying an inert gas between the shielding wall 12 and the inner wall of the processing vessel 24, leakage of hydrogen gas from the processing space 32 to outside the processing vessel 24 can be reliably prevented.

Furthermore, according to this embodiment, by configuring the apparatus to purge the entire shower head 54 with an inert gas, even if hydrogen gas leaks from the shower head 54, it is possible to reliably prevent the hydrogen gas from leaking outside the processing vessel 24. In addition, the inflow of combustion-supporting gas into the processing space 32 can be suppressed.

In addition, according to this embodiment, by providing the inert gas supply port 18 at the position of the upper end 14a of the shielding wall 14 or at a position higher than the upper end, a cooling effect of the shielding wall 14 can be obtained by the inert gas flowing along the outer periphery of the shielding wall 14.

(Modification of the inert gas supply port)
7, the inert gas supply port 18 may be configured as a shower head 94 having a plurality of inert gas ejection holes 94a. In this configuration, the inert gas introduced from the inert gas supply port 18 is supplied to a buffer space 97 in the shower head 94, and is dispersed and supplied from the buffer space 97 into the processing vessel 24 through the plurality of inert gas ejection holes 94a.

[Second embodiment]
8 to 10, in the substrate processing apparatus 20 according to the present embodiment, the shielding wall 14 and the inert gas supply port 18 are provided on the ceiling surface 24e of the processing vessel 24. Specifically, a shower head 54 for processing gas is incorporated in the center of the ceiling surface 24e of the processing vessel 24. In addition, the shielding wall 14 is used on the radial outside of the shower head 54 on the ceiling surface 24e. The shielding wall 14 is formed, for example, in a cylindrical shape and is provided separately from the shower head 54. The inert gas supply port 18 is provided between the shielding wall 14 and the inner wall 24c of the processing vessel 24. The inert gas supply port 18 is, for example, a plurality of equally arranged in the circumferential direction, opens on the ceiling surface 24e of the processing vessel 24, and is configured to supply the inert gas along the shielding wall 14 from the upper end 14a of the shielding wall 14 to the lower end.

The processing vessel 24 is divided into an upper chamber 100 in which the substrate holder 12 is disposed, and a lower chamber 102 to which an exhaust section is connected. The upper chamber 100 and the lower chamber 102 are divided by a partition wall 104, and the partition wall 104 has a communication hole 104a that connects the upper chamber 100 and the lower chamber 102.

The substrate holder 12 is supported by, for example, a number of shafts 46. The shafts 46 and the substrate holder 12 are raised and lowered by the operation of a lifting mechanism 48. The configurations of the processing vessel 24 and the lifting mechanism 48 may be the same as those in the first embodiment.

8, in the substrate processing apparatus 20 according to this embodiment, the substrate 30 is loaded into the processing chamber 24 with the substrate holding table 12 lowered. The loaded substrate 30 is supported in a horizontal position on lift pins 36 protruding from the surface of the substrate holding table 12. As shown in FIG. 9, the lifting mechanism 48 raises the substrate holding table 12, so that the substrate 30 is supported on the upper surface 38 (specifically, the mounting surface 38a) of the substrate holding table 12. A processing space 32 is formed between the upper surface 38 of the substrate holding table 12 and the opposing surface 52 of the shower head 54. The processing space 32 and the outer periphery 12b of the substrate holding table 12 are surrounded by a shielding wall 14.

10, in the reactive gas supply step S130 (FIG. 6), the processing gas is dispersed by the shower head 54 provided on the ceiling surface 24e of the processing vessel 24 and supplied to the processing space 32. The inert gas enters the processing vessel 24 from the inert gas supply port 18, which is located at the upper end 14a of the shielding wall 14 or at a position higher than the upper end 14a, and is supplied along the shielding wall 14 from the upper end to the lower end of the shielding wall 14. The processing gas leaving the processing space 32 passes through the processing gas flow path 56 between the shielding wall 14 and the substrate holding table 12, and merges with the inert gas at the point where it leaves the processing gas flow path 56, is mixed with the inert gas, and reaches the gas mixing section 22 below.

As other parts are similar to those of the first embodiment, the same or corresponding parts are denoted by the same reference numerals in the drawings and the description thereof is omitted. In addition, the MFC and valves that control the supply of the processing gas from the processing gas supply port 16 and the supply of the inert gas from the inert gas supply port 18 are also not shown, but have the same structure as those of the first embodiment.

[Other embodiments]
An example of an embodiment of the present disclosure has been described above, but the embodiment of the present disclosure is not limited to the above, and it goes without saying that various modifications can be made without departing from the spirit and scope of the present disclosure.

When the substrate holder 12 is raised to the processing position, the distance between the substrate 30 and the facing surface 52 is controlled to be, for example, 2 cm or less. By setting this distance to 2 cm or less, the volume of the processing space 32 can be limited to a level at which the above-mentioned effect can be practically obtained. In this state, the distance between the substrate 30 and the facing surface 52 is controlled to be, for example, 0.5 cm or more. By setting this distance to 0.5 cm or more, it is possible to suppress the bias in the temperature distribution on the underside of the shower head 54 from affecting the in-plane temperature distribution on the substrate 30. The volume of the processing space 32 is adjusted by controlling the lifting mechanism 48 in the range where the outer periphery 12b of the substrate holder 12 and the shielding wall 14 overlap.

Furthermore, when the substrate holder 12 is raised to the processing position, the vertical length from the outer upper surface 38b of the substrate holder 12 to the lower end of the shielding wall 14 is, for example, 5 cm or more. By making this length 5 cm or more, it is possible to prevent gases other than the processing gas from flowing into the processing space 32 through the processing gas flow path 56. In addition, in this state, the radial distance of the substrate holder 12 between the outer periphery 12b of the substrate holder 12 and the shielding wall 14 is, for example, 1 cm or less. This distance corresponds to the width of the processing gas flow path 56 in the radial cross section of the substrate holder 12. By making this distance 1 cm or less, it is possible to prevent gases other than the processing gas from flowing into the processing space 32 through the processing gas flow path 56. In addition, this distance is 0.1 cm or more. By making this distance 0.1 cm or more, it is possible to ensure a practical conductance of the processing gas flow path 56.

Although the above describes the substrate processing apparatuses 10 and 20 that process substrates 30 one by one, the present invention is not limited to this and may be a batch-type apparatus in which multiple substrates 30 are arranged horizontally in the processing vessel 24.

Furthermore, although the above describes the manufacturing process of a semiconductor device, the disclosed technology according to the embodiment can be applied to processes other than the manufacturing process of a semiconductor device. For example, there are substrate processes such as the manufacturing process of liquid crystal devices, the manufacturing process of solar cells, the manufacturing process of light-emitting devices, the processing process of glass substrates, the processing process of ceramic substrates, and the processing process of conductive substrates.

Claims (17)

a substrate holding stage that holds a substrate and is movable up and down within the processing vessel;
a shielding wall that does not come into contact with the substrate holding table in a raised state and the substrate, and that surrounds a processing space between an upper surface of the substrate holding table and an opposing surface to the upper surface, and an outer periphery of the substrate holding table in a raised state;
a processing gas supply port for supplying a processing gas containing hydrogen gas to the processing space;
an inert gas supply port provided outside the processing space and outside the shielding wall, the inert gas supply port supplying an inert gas to a space between the shielding wall and an inner wall of the processing vessel;
a gas mixing section in which the processing gas discharged from the processing space is mixed with the inert gas inside the processing vessel;
a processing gas flow path formed between an outer circumferential surface of the substrate holding table in a raised state and an inner circumferential surface of the shielding wall, the processing gas being configured to flow from the processing space toward the gas mixing section;
having
a space between the shielding wall and an inner wall of the processing vessel, the space being configured to communicate the inert gas supply port and the gas mixing unit outside the processing space . The substrate processing apparatus according to claim 1, wherein the processing gas supply port is composed of one or more processing gas outlet holes provided on the facing surface. the processing gas supply port is configured by a shower head having the plurality of processing gas ejection holes provided on the facing surface,
3. The substrate processing apparatus according to claim 2, wherein the shower head is provided in the processing vessel away from a ceiling surface of the processing vessel. The substrate processing apparatus according to claim 3, wherein the inert gas is supplied from the inert gas supply port between the upper surface of the shower head and the ceiling surface of the processing vessel, and reaches the space between the shielding wall and the inner wall of the processing vessel. The substrate processing apparatus according to claim 4, wherein the inert gas supply port is provided at least toward the center of the ceiling surface of the processing vessel relative to the outer edge of the shower head. The substrate processing apparatus according to claim 3, wherein the inert gas supply ports are provided in a circumferential direction along the outer edge of the shower head on the ceiling surface of the processing vessel. The substrate processing apparatus according to claim 3, wherein the shielding wall is provided on the shower head. The substrate processing apparatus according to claim 1 , wherein the inert gas supply port is provided inside the inner wall at a position equal to or higher than an upper end of the shielding wall. The substrate processing apparatus according to claim 8, wherein the shielding wall and the inert gas supply port are provided on the ceiling surface of the processing vessel. a flow rate control device for controlling a flow rate of the processing gas supplied to the processing gas supply port;
an exhaust unit configured to exhaust an atmosphere in the processing vessel;
a control unit configured to control the flow rate control device and the exhaust unit to adjust the pressure in the processing space to atmospheric pressure or a slightly reduced pressure relative to atmospheric pressure;
The substrate processing apparatus of claim 1 , further comprising: The substrate processing apparatus according to claim 10, wherein the concentration of hydrogen gas in the processing gas is 4% or more. The substrate processing apparatus according to claim 11, wherein the flow rate of the inert gas supplied from the inert gas supply port into the processing vessel is adjusted so that the concentration of hydrogen gas in the gas mixing section is less than 4%. The substrate processing apparatus according to claim 11, wherein the concentration of hydrogen gas in the processing gas is 100%. a flow rate control device for controlling a flow rate of the inert gas supplied to the inert gas supply port;
a control unit configured to control the flow rate control device to adjust the flow rate of the inert gas supplied from the inert gas supply port to be 24 times or more the flow rate of the processing gas supplied from the processing gas supply port;
The substrate processing apparatus of claim 1 , further comprising: The substrate processing apparatus according to claim 1, wherein the lower end position of the substrate holder in the raised state is lower than the lower end position of the shielding wall. a substrate holding stage that holds a substrate and is movable up and down within the processing vessel;
a shielding wall that does not come into contact with the substrate holding table in a raised state and the substrate, and that surrounds a processing space between an upper surface of the substrate holding table and an opposing surface to the upper surface, and an outer periphery of the substrate holding table in a raised state;
a processing gas supply port for supplying a processing gas containing hydrogen gas to the processing space;
an inert gas supply port provided outside the processing space and outside the shielding wall, the inert gas supply port supplying an inert gas to a space between the shielding wall and an inner wall of the processing vessel;
a substrate loading step of placing the substrate on the substrate holding table of a substrate processing apparatus having a gas mixing section in which the processing gas discharged from the processing space is mixed with the inert gas inside the processing vessel, and a processing gas flow path formed between an outer circumferential surface of the substrate holding table in a raised state and an inner circumferential surface of the shielding wall, the processing gas flow path being configured so that the processing gas flows from the processing space toward the gas mixing section, the space between the shielding wall and the inner wall of the processing vessel being configured so that the inert gas supply port and the gas mixing section are communicated outside the processing space;
a processing step of performing a process on the substrate using the processing gas;
a substrate unloading step of unloading the substrate from the processing chamber;
A method for manufacturing a semiconductor device having the above structure. a substrate holding stage that holds a substrate and is movable up and down within the processing vessel;
a shielding wall that does not come into contact with the substrate holding table in a raised state and the substrate, and that surrounds a processing space between an upper surface of the substrate holding table and an opposing surface to the upper surface, and an outer periphery of the substrate holding table in a raised state;
a processing gas supply port for supplying a processing gas containing hydrogen gas to the processing space;
an inert gas supply port provided outside the processing space and outside the shielding wall, the inert gas supply port supplying an inert gas to a space between the shielding wall and an inner wall of the processing vessel;
a gas mixing section in which the process gas discharged from the process space is mixed with the inert gas inside the process vessel, and a process gas flow path formed between an outer circumferential surface of the substrate holding table in a raised state and an inner circumferential surface of the shielding wall, the process gas flowing from the process space toward the gas mixing section , wherein a space between the shielding wall and an inner wall of the process vessel is configured to connect the inert gas supply port and the gas mixing section outside the process space ,
placing the substrate on the substrate holder;
performing a process on the substrate using the process gas;
unloading the substrate from the processing chamber;
A program for causing a computer to execute the above-mentioned substrate processing apparatus.