JPH09148287A - Wafer storing method, wafer treating method and thin film forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To hold the clean surface of a wafer having at least a surface for a long time and particularly to effectively suppress the formation of a natural oxide film by dipping the part or entirety of the wafer in liquid metal, thereby holding the surface of the wafer dipped in the metal clean without oxidizing. SOLUTION: Liquid metal 12 made of gallium is stored in a bath 14. The bath may be manufactured by the material which is not reacted with or not eroded by the metal 12. A heater 16 is disposed around the bath 14, and the metal 12 is heated to the melting point to the boiling point by the heater 16. The entirety of the bath 10 made of a silicon semiconductor wafer is dipped in the metal 12. Thus, the surface of the wafer 10 is not brought into contact with the atmosphere, thereby making it possible to effectively suppress the formation of the oxide film on the surface of the wafer 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel substrate storage method, substrate processing method and thin film deposition method, and more particularly to a substrate storage method, substrate processing method and thin film deposition method suitable for manufacturing semiconductor devices.

[0002]

2. Description of the Related Art A surface treatment method for a semiconductor substrate and a surface treatment method for a thin film formed on the surface of a semiconductor substrate are extremely important technical matters in the manufacturing process of a semiconductor device, and various surface treatment methods have been developed. ing. For example, for cleaning the surface of a silicon semiconductor substrate, H ₂ O ₂ / NH ₄ OH is used.
A RCA cleaning method using a / H ₂ O solution has been developed, and a dilute HF cleaning method has been developed to remove a natural oxide film on the surface of a silicon semiconductor substrate.

These surface treatment methods are extremely effective for cleaning the surface of a silicon semiconductor substrate and are widely used. However, the surface of the silicon semiconductor substrate is extremely active, and after the surface treatment, a natural oxide film, which causes deterioration of electrical characteristics, is formed on the surface of the silicon semiconductor substrate again before the next semiconductor device manufacturing process is performed. There is a problem of being formed.

[0004]

In order to remove this natural oxide film, a method is employed in which the surface treatment of a silicon semiconductor substrate is carried out in an apparatus used in a semiconductor device manufacturing process immediately before the semiconductor device manufacturing process is executed. There is. For example, a method of heating a silicon semiconductor substrate to about 900 ° C. in a high vacuum to evaporate a natural oxide film formed on the surface of the silicon semiconductor substrate to form a clean surface again is adopted. However, this method
The silicon semiconductor substrate has to be heated to a high temperature of about 900 ° C., which has a drawback that it cannot be applied to a low-temperature process, and a material having low heat resistance such as glass cannot be used as a substrate. There is also.

As another method, a method of forming a clean surface by etching the surface of a silicon semiconductor substrate with hydrogen plasma has been adopted. This method is an excellent method in that the surface treatment can be performed at a low temperature, but has a drawback that it is difficult to remove a thick natural oxide film. Further, the hydrogen plasma treatment may damage the surface of the silicon semiconductor substrate.

Therefore, a first object of the present invention is to provide a substrate storage method capable of holding a clean substrate surface for a long time and effectively suppressing the formation of a natural oxide film. A second object of the present invention is to provide a method for treating a substrate, which can keep a clean substrate surface for a long time and particularly effectively suppress the formation of a natural oxide film. A third object of the present invention is to provide a method for forming a thin film on a substrate, including a method for treating a substrate, which can effectively suppress the formation of a natural oxide film.

[0007]

The method for storing a substrate of the present invention for achieving the above object is characterized in that a part or the whole of the substrate including at least the surface is immersed in a liquid metal.

In the substrate storing method of the present invention, or the substrate treating method or thin film forming method of the present invention described later, the liquid metal is selected from metallic materials having a low melting point and a high boiling point and not reacting with the substrate. Well, as a liquid metal,
Mention may be made of gallium or indium. Generally, the solid solution limit of a metal in a semiconductor material is low, but as the temperature rises, the mutual diffusivity between the metal and the semiconductor material increases. Therefore, the temperature of the liquid metal in the present invention is preferably 700 ° C. or lower, the melting point or higher, and the temperature as low as possible. In order to prevent the material constituting the substrate from dissolving into the liquid metal, it is sufficient to use a liquid metal in which the components of the material constituting the substrate have been dissolved in advance to near the saturation concentration or above the saturation concentration. . For example, when the substrate is a silicon semiconductor substrate, gallium or indium in which silicon is dissolved may be used as the liquid metal.

In the method for storing a substrate of the present invention, or the method for treating a substrate or the method for forming a thin film of the present invention described later, the substrate is a silicon semiconductor substrate, a gallium nitride substrate, a III-V group compound semiconductor substrate, II- V
Semiconductor substrates such as group I compound semiconductor substrates, group III-V compound semi-insulating substrates, group II-VI compound semi-insulating substrates,
Examples include a substrate having various thin films formed on these substrates, a metal plate, a plastic material having a magnetic thin film formed on the surface thereof, and a plastic material having a magneto-optical material thin film formed on the surface thereof.

A method of treating a substrate according to the present invention for achieving the above-mentioned object comprises (a) a step of cleaning the surface of the substrate,
(B) A step of immersing a part or the whole of the substrate including at least the surface of the substrate in the liquid metal. The substrate processing method of the present invention may further include (c) a step of evacuating the atmosphere in contact with the liquid metal after the step (b). Alternatively, the step (b)
After that, the method may further include the step of (c) making the atmosphere in contact with the liquid metal a reducing atmosphere.

The thin film forming method of the present invention for achieving the above object comprises (a) a step of cleaning the surface of a substrate, and (b)
A step of immersing a part or the whole of the substrate including at least the surface of the substrate in a liquid metal; (c) a step of removing the substrate from the liquid metal; and (d) a step of forming a thin film on the surface of the substrate. Characterize.

In the thin film forming method of the present invention, the thin film is made of a semiconductor thin film, and after the step (b), the method further comprises the step of evacuating the atmosphere in contact with the liquid metal to form a thin film. , Molecular beam epitaxy (MBE) method, chemical vapor deposition (CV) in a reduced pressure atmosphere
D) method, metal organic CVD (MOCVD) method, plasma C
It can be performed by the VD method, the sputtering method or the evaporation method. Alternatively, the thin film is composed of a metal thin film or a metal compound thin film, and further includes a step of evacuating the atmosphere in contact with the liquid metal after the step (b).
The thin film can be formed in a reduced pressure atmosphere. Furthermore, the thin film further comprises a step of evacuating the atmosphere in contact with the liquid metal after the step (b) after the step (b), in which the thin film is formed by chemical vaporization in a reduced pressure atmosphere. It can be performed by a phase growth (CVD) method, a plasma CVD method, a sputtering method or an evaporation method. Alternatively, the thin film comprises a semiconductor thin film, and after the step (b), the method further comprises the step of changing the atmosphere in contact with the liquid metal to a reducing atmosphere. In this case, the thin film is formed by atmospheric pressure chemical vapor deposition ( CV
D) method, atmospheric pressure metalorganic CVD (MOCVD) method or liquid phase growth method can be used. Furthermore, the thin film comprises a metal thin film or a metal compound thin film, and after the step (b), the method further includes a step of changing the atmosphere in contact with the liquid metal to a reducing atmosphere. In this case, the thin film is formed under a normal pressure atmosphere. Can be done in Alternatively, the thin film is made of an insulating film, and after the step (b), the method further includes the step of changing the atmosphere in contact with the liquid metal to a reducing atmosphere. In this case, the thin film is formed by atmospheric pressure chemical vapor deposition ( The CVD method, the vapor phase growth method or the thermal oxidation method can be used.

In the method of treating a substrate or the method of forming a thin film of the present invention, examples of methods for washing the surface of the substrate include washing of the substrate with water, RCA cleaning, and diluted HF cleaning.

In the present invention, a part or the whole of the substrate including at least the surface is immersed in the liquid metal, so that the surface of the substrate is kept clean without being oxidized. Therefore, it is not necessary to apply the conventional substrate surface treatment method to the substrate. If a liquid metal having appropriate properties is used, the surface of the substrate will not react with the liquid metal or be altered by the liquid metal.

In the method for treating a substrate or the method for forming a thin film of the present invention, after dipping a part or the whole of the substrate including at least the surface in a liquid metal, the atmosphere in contact with the liquid metal is evacuated, or the liquid metal is used. If the atmosphere in contact with is a reducing atmosphere such as hydrogen gas, after taking out the substrate from the liquid metal, various processes including a thin film forming step can be directly carried out on the substrate having a clean surface.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described based on embodiments with reference to the drawings.

(Example 1) Example 1 relates to the substrate storage method of the present invention. As shown in the schematic view of FIG. 1, a liquid metal 12 made of, for example, gallium is stored in a container 14. The container may be made of a material that does not react with the liquid metal 12 or be corroded by the liquid metal 12. A heater 16 is arranged around the container 14, and the liquid metal 12 is heated by the heater 16 to a temperature above the melting point and below the boiling point. In this state, the entire substrate 10 made of, for example, a silicon semiconductor substrate is immersed in the liquid metal 12. As a result, the surface of the substrate 10 is prevented from coming into contact with the atmosphere, and the formation of an oxide film on the surface of the substrate 10 can be effectively suppressed. While the substrate 10 made of the silicon semiconductor substrate is stored in the liquid metal 12 made of gallium, the substrate 10 and the liquid metal 12 do not react with each other. Regarding the presence or absence of the reaction between the substrate 10 and the liquid metal 12 as described above, the document "First MOS Transistors on Ins"
ulator by Silicon Saturated Liquid Solution Epitax
y ", RP Zingg, et al, IEEE ELECTRON DEVICE LETTE
See RS, VOL 13, No. 5, May, 1992, pp 294-296.

(Example 2) Example 2 relates to a method for treating a substrate of the present invention. In the second embodiment, first, the surface of the base 10 made of, for example, a silicon semiconductor substrate is removed by RCA.
Cleaning is performed by a cleaning method or a diluted HF method. With proper washing, the surface of the substrate becomes a clean surface without a natural oxide film. However, if the substrate is left in the air after cleaning, the surface of the substrate is oxidized by oxygen in the air. In the method for treating a substrate of the present invention, after cleaning the substrate surface,
Immediately (ie, before the native oxide film is formed on the surface of the substrate), the substrate 10 is immersed in the liquid metal 12. This can effectively prevent the formation of a natural oxide film on the surface of the substrate 10. Since the liquid metal 12 is generally reducible, the substrate 10 held in the liquid metal 12 is
The surface is kept clean without being oxidized.

(Embodiment 3) Embodiment 3 relates to a substrate processing method and a thin film forming method of the present invention. In Example 3, a thin film made of a semiconductor thin film was formed by the molecular beam epitaxy (MBE) method in a reduced pressure atmosphere.
FIG. 2 shows an outline of an MBE apparatus suitable for carrying out the substrate processing method and thin film deposition method of Example 3. This MBE device itself is a known device, and is composed of a film forming chamber 20 and a loading / unloading chamber (load lock chamber) 30. Each of the film forming chamber 20 and the carry-in / out chamber 30 is equipped with an ultra-high vacuum pump (not shown) such as an ion pump or a turbo molecular pump, and the ultra-high vacuum pump is provided via the gas discharge parts 22 and 32. The interior of the film forming chamber 20 and the carry-in / out chamber 30 are evacuated by an ultra high vacuum of about 10 ⁻⁸ Pa (1.3 × 10 ⁻⁶ Pa) or less. A gate valve 34 is arranged between the film forming chamber 20 and the loading / unloading chamber 30. Further, a gate valve 36 for loading / unloading the substrate into / from the loading / unloading chamber 30 is arranged in the loading / unloading chamber 30.

In the film forming chamber 20, a substrate holding part 24 for placing the substrate 10 and holding it at a predetermined temperature is arranged. The film forming chamber 20 further includes a molecular beam source cell 26 including a Knudsen cell (K-cell) in which a molecular beam source is housed.
Is provided. This Knudsen cell is, for example, a PB
It consists of an N crucible and a heater placed around it. A molecular beam source is housed in the crucible, and the crucible is heated by a heater to generate a molecular beam. The generated molecular beam is emitted toward the substrate 10. By controlling the heater, the amount of generated molecular beam can be controlled. The temperature of the crucible is measured by a thermocouple. The crucible and heater are contained in a case. The flow of the molecular beam is controlled by opening and closing a shutter (not shown) for the molecular beam source.

In carrying out the method for treating a substrate and the method for forming a thin film of the present invention, a liquid metal 1 made of, for example, gallium 1
2 is stored in the container 14. Then, a heater (not shown) is arranged around the container 14, and the liquid metal 12 is heated by the heater to a temperature above the melting point and below the boiling point.
Then, first, the surface of the substrate 10 made of a GaAs substrate is cleaned by the RCA cleaning method or the diluted HF method. Then, immediately (that is, before the natural oxide film is formed on the surface of the substrate), the substrate 10 is immersed in the liquid metal 12 (see FIG. 2A).

Thereafter, with the substrate 10 immersed in the liquid metal 12, the container 14 is passed through the gate valve 36 to pass the MB.
The device E is carried into the carry-in / carry-out chamber 30 (see FIG. 2B). In addition, the inside of the film forming chamber 20 is previously maintained in an ultrahigh vacuum, and the gate valve 34 is closed. Then, the gate valve 36 is closed and the atmosphere in contact with the liquid metal 12 (specifically, the inside of the carry-in / out chamber 30) is evacuated.
When the inside of the loading / unloading chamber 30 reaches a desired degree of vacuum, the gate valve 34 is opened, and the substrate 10 is taken out of the liquid metal 12 by a substrate transfer device (not shown).
The substrate 10 is placed on the substrate holding part 24. Next, after holding the substrate 10 and the molecular beam source cell 26 at a predetermined temperature,
By opening the shutter for the molecular beam source, a thin film 18 made of, for example, a III-V group compound semiconductor thin film is formed on the surface of the substrate 10 (see FIG. 3). When the film formation of the thin film 18 is completed, the shutter for the molecular beam source is closed, the substrate 10 is cooled, and then the substrate 10 is carried out from the film forming chamber 20 to the carry-in / out chamber 30 by using the substrate carrying device.

After that, the substrate 10 may be unloaded from the loading / unloading chamber 30 as it is, or the substrate 10 may be unloaded from the loading / unloading chamber 30 after the substrate 10 is immersed in the liquid metal 12 again.

According to the method of treating a substrate and the method of forming a thin film of Example 3, it is possible to prevent oxygen in the atmosphere from contacting the surface of the substrate after cleaning the surface of the substrate and prevent the formation of a natural oxide film. be able to. Therefore, it is not necessary to remove the oxide film by high temperature heating or the like in the MBE apparatus before the epitaxy growth which is conventionally performed.

The thin film forming method described in the third embodiment is not limited to the MBE method, but other methods such as a chemical vapor deposition (CVD) method and a metal organic chemical vapor deposition (MO) method in a reduced pressure atmosphere can be used.
It can be applied to a CVD method, a plasma CVD method, a sputtering method or an evaporation method.

(Embodiment 4) The substrate processing method or thin film forming method of the present invention can also be applied to the formation of an insulating film or a metal thin film or a metal compound thin film in a reduced pressure atmosphere. FIG. 4 shows a method of forming a thin film made of an insulating film on a base made of a silicon semiconductor substrate by the RF sputtering method.

The sputtering apparatus itself suitable for carrying out the substrate processing method and thin film deposition method of Example 4 shown in FIG. 4 is a known apparatus, and is composed of a deposition chamber 40 and a loading / unloading chamber 50. A vacuum pump (not shown) is provided in each of the film forming chamber 40 and the carry-in / out chamber 50, and the gas exhaust unit 4 is provided.
The inside of the film formation chamber 40 and the inside of the carry-in / out chamber 50 are evacuated by a vacuum pump through 2, 52. Film forming chamber 40
A gate valve 54 is disposed between the loading / unloading chamber 50 and the loading / unloading chamber 50. Further, a gate valve 56 for loading / unloading the substrate into / from the loading / unloading chamber 50 is arranged in the loading / unloading chamber 50.

In the film forming chamber 40, a substrate holding portion 44 for mounting the substrate 10 and holding it at a predetermined temperature is arranged. The film forming chamber 40 further includes a target 46 and a gas introducing unit 48 for supplying a process gas to the film forming chamber 40.
Is provided.

In the fourth embodiment, first, the surface of the substrate 10 made of a silicon semiconductor substrate is cleaned by the RCA cleaning method or the diluted HF method. Then, immediately (that is, before the native oxide film is formed on the surface of the substrate), the substrate 10 is immersed in the liquid metal 12.

Then, with the substrate 10 immersed in the liquid metal 12, the container 14 is loaded into the loading / unloading chamber 50 of the sputtering apparatus through the gate valve 56 (see FIG. 4A). In addition, the inside of the film forming chamber 40 is kept in vacuum in advance, and the gate valve 54 is closed. Then, the gate valve 56 is closed and the atmosphere in contact with the liquid metal 12 (specifically, the inside of the carry-in / out chamber 50) is evacuated. When the inside of the carry-in / out chamber 50 reaches a desired degree of vacuum, the gate valve 5
4 is opened, and the substrate 1 is transferred by a substrate transfer device (not shown).
0 is taken out from the liquid metal 12, and the substrate 10 is placed on the substrate holding portion 44 of the film forming chamber 40. Next, after the substrate 10 is maintained at a predetermined temperature, a voltage is applied to the target 46 while introducing a process gas into the film forming chamber 40 from the gas introducing unit 48, and a thin film made of an insulating film is formed on the surface of the substrate 10. 18
A is deposited (see FIG. 4B). When the film formation of the thin film 18A is completed, the application of the voltage to the target 46 is stopped, the substrate 10 is cooled, and then the substrate 10 is unloaded from the film deposition chamber 40 to the loading / unloading chamber 50 by using the substrate transporting device.

After that, the substrate 10 may be carried out from the carry-in / out chamber 50 as it is, or the substrate 10 may be carried out from the carry-in / out chamber 50 after the substrate 10 is immersed in the liquid metal 12 again.

According to the substrate processing method and the thin film forming method of Example 4, it is possible to prevent oxygen in the atmosphere from coming into contact with the surface of the substrate after cleaning the surface of the substrate, and to prevent the formation of a natural oxide film. be able to. Therefore, it is not necessary to remove the oxide film by hydrogen plasma or the like before sputtering which has been conventionally performed. Then, the insulating film can be formed under the condition that a natural oxide film having poor electrical characteristics does not exist, and a good insulating film / substrate interface can be formed.

Further, according to the substrate processing method and the thin film forming method of the fourth embodiment, a metal thin film (for example, a Ti film or a Pt film,
Au film) or metal compound thin film (eg TiN film or T
By forming the iON film), a metal thin film or a metal compound thin film can be formed under the condition that there is no natural oxide film, and for example, a metal / substrate interface having excellent ohmic characteristics can be formed.

The thin film forming method described in the fourth embodiment is not limited to the sputtering method, and other methods such as a chemical vapor deposition (CVD) method and a plasma CVD method in a reduced pressure atmosphere are also applicable.
Method or evaporation method.

(Embodiment 5) The substrate treating method or thin film forming method of the present invention can be applied to the case where a semiconductor thin film, an insulating film, or a metal thin film or a metal compound thin film is formed under normal pressure. it can. FIG. 5 shows a method of forming a thin film made of an insulating film on a substrate made of a silicon semiconductor substrate by the atmospheric pressure CVD method.

The atmospheric pressure CVD apparatus itself suitable for carrying out the substrate processing method and thin film forming method of Example 5 shown in FIG. 5 is a known apparatus, and is composed of a film forming chamber 60 and a loading / unloading chamber 70. . In each of the film forming chamber 60 and the carry-in / out chamber 70,
An exhaust pump (not shown) is provided, and the gas in the film forming chamber 60 and the carry-in / out chamber 70 is reduced to a reducing gas (for example, hydrogen gas) by being exhausted by the exhaust pump via the gas exhaust units 62 and 72. Will be replaced. Film forming chamber 60 and loading / unloading chamber 70
A gate valve 74 is provided between the and. Further, a gate valve 76 for loading / unloading the substrate to / from the loading / unloading chamber 70 is arranged in the loading / unloading chamber 71. Further, a gas introduction part 78 for introducing a reducing gas such as hydrogen gas into the loading / unloading chamber 70 is provided in the loading / unloading chamber 70 in order to make the loading / unloading chamber 70 have a reducing atmosphere.

In the film forming chamber 60, a substrate holding portion 64 for placing the substrate 10 and holding it at a predetermined temperature is arranged. The film forming chamber 60 is further provided with a gas introducing unit 66 for supplying a film forming gas to the film forming chamber 60.
A heater 68 for maintaining the entire film forming chamber 60 at a predetermined temperature is arranged outside the film forming chamber 60.

In the fifth embodiment, first, the surface of the substrate 10 made of a silicon semiconductor substrate is washed by the RCA cleaning method or the diluted HF method. Then, immediately (that is, before the native oxide film is formed on the surface of the substrate), the substrate 10 is immersed in the liquid metal 12.

Thereafter, with the substrate 10 immersed in the liquid metal 12, the container 14 is loaded into the loading / unloading chamber 70 of the atmospheric pressure CVD apparatus through the gate valve 76 ((A) of FIG. 5).
reference). The film forming chamber 60 is evacuated in advance and replaced with a reducing gas such as hydrogen gas, and the gate valve 74 is kept closed. Then, the gate valve 76 is closed,
Atmosphere in contact with liquid metal 12 (specifically, loading / unloading chamber 7
0) is made a reducing atmosphere. Therefore, the carry-in / out room 7
A reducing gas such as hydrogen gas is introduced into the carry-in / out chamber 70 from the gas introducing unit 78 while evacuating 0. When the inside of the carry-in / out chamber 70 becomes a reducing atmosphere, the gate valve 74 is opened, the substrate 10 is taken out of the liquid metal 12 by a substrate transfer device (not shown), and the substrate holding portion 64 of the film forming chamber 60 is opened.
The substrate 10 is placed on. Next, after the substrate 10 is maintained at a predetermined temperature, a film forming gas is introduced into the film forming chamber 60 from the gas introduction unit 66 to form a thin film 18A made of an insulating film on the surface of the substrate 10 (FIG. 5 (B)). Thin film 18A
When the film formation of is completed, the supply of film forming gas is stopped,
After the substrate 10 is cooled, the substrate transport device is used to form the film forming chamber 6
The substrate 10 is carried out from 0 to the carry-in / out chamber 70.

After that, the substrate 10 may be unloaded from the loading / unloading chamber 70 as it is, or the substrate 10 may be unloaded from the loading / unloading chamber 70 after being immersed in the liquid metal 12 again.

According to the method of treating a substrate and the method of forming a thin film of Example 5, after cleaning the surface of the substrate, it is possible to prevent oxygen in the atmosphere from contacting the surface of the substrate and prevent the formation of a natural oxide film. be able to. Therefore, the conventional CVD
It is not necessary to remove the oxide film by the previous hydrogen plasma or the like. Then, the insulating film can be formed under the condition that a natural oxide film having poor electrical characteristics does not exist, and a good insulating film / substrate interface can be formed.

The method described in Example 5 is the atmospheric pressure CVD.
The present invention is not limited to this method, but can be applied to film formation using atmospheric pressure MOCVD or liquid phase epitaxy, for example. Furthermore,
It can also be applied to a method of forming an insulating film on the surface of a substrate made of a silicon semiconductor substrate in a normal pressure atmosphere by using a thermal oxidation method. Since there is no natural oxide film, a good insulating film / silicon semiconductor substrate interface can be formed.

The present invention has been described above based on the preferred embodiments, but the present invention is not limited to these embodiments. The structures of various devices described in the embodiments are examples, and can be changed as appropriate.

[0044]

According to the present invention, the surface of the substrate is covered with the liquid metal. Since the liquid metal is generally reducible, the surface of the substrate immersed in the liquid metal is kept clean without being oxidized. Therefore, for example, when forming a thin film on the surface of the substrate, it is not necessary to perform surface treatment of the substrate. Moreover, in the method for treating a substrate or the method for forming a thin film of the present invention, after immersing a part or the whole of the substrate including at least the surface in the liquid metal, the atmosphere in contact with the liquid metal is evacuated, or If a reducing atmosphere such as hydrogen gas is used as the atmosphere in contact with the substrate, after the substrate is taken out of the liquid metal, various processes including a thin film forming process can be directly performed on the substrate having a clean surface. The process can be simplified.

[Brief description of the drawings]

FIG. 1 is a schematic view of a substrate, a liquid metal, etc. for explaining a substrate storage method of the present invention.

FIG. 2 is a diagram schematically showing each step when the substrate processing method and thin film forming method of the present invention are applied to a thin film forming method by a molecular beam epitaxy method.

FIG. 3 is a diagram schematically showing the process of applying the substrate processing method and the thin film forming method of the present invention to the thin film forming method by the molecular beam epitaxy method subsequent to FIG. 2;

FIG. 4 is a diagram schematically showing each step when the substrate processing method and thin film forming method of the present invention are applied to a thin film forming method by a sputtering method.

FIG. 5 is a diagram schematically showing each step when the substrate processing method and thin film forming method of the present invention are applied to a thin film forming method by an atmospheric pressure CVD method.

[Explanation of symbols]

 10 substrate 12 liquid metal 14 container 16 heater 18, 18A thin film 20, 40, 60 film forming chamber 22, 32, 42, 52, 62, 72 gas discharge part 24, 44, 64 substrate holding part 26 molecular beam source cell 30, 50,70 Carry-in / out chamber 34,36,54,56,74,76 Gate valve 46 Target 48,66,78 Gas introduction part

Claims (14)

[Claims] 1. A method for storing a substrate, characterized in that a part or the whole of the substrate including at least the surface is immersed in a liquid metal. 2. The method of storing a substrate according to claim 1, wherein the substrate is a semiconductor substrate and the liquid metal is gallium or indium. 3. A method for treating a substrate, comprising: (a) a step of cleaning the surface of the substrate; and (b) a step of immersing a part or the whole of the substrate including at least the surface of the substrate in a liquid metal. 4. The method for treating a substrate according to claim 3, wherein the substrate is a semiconductor substrate and the liquid metal is gallium or indium. 5. The method for treating a substrate according to claim 3, further comprising the step of: (c) after the step (b), evacuation of the atmosphere in contact with the liquid metal. 6. The method for treating a substrate according to claim 3, further comprising the step of: (c) after the step (b), the step of making the atmosphere in contact with the liquid metal a reducing atmosphere. 7. (a) a step of cleaning the surface of the substrate; (b) a step of immersing a part or the whole of the substrate including at least the surface of the substrate in a liquid metal; and (c) a step of removing the substrate from the liquid metal. And (d) a step of forming a thin film on the surface of the base body. 8. The method of forming a thin film according to claim 8, wherein the base body is a semiconductor substrate, and the liquid metal is gallium or indium. 9. The thin film comprises a semiconductor thin film, and after the step (b), the method further comprises the step of evacuating the atmosphere in contact with the liquid metal, wherein the thin film is formed by molecular beam epitaxy in a reduced pressure atmosphere. The thin film forming method according to claim 7, which is carried out by an MBE) method, a chemical vapor deposition (CVD) method, a metal organic CVD (MOCVD) method, a plasma CVD method, a sputtering method or an evaporation method. 10. The thin film comprises a metal thin film or a metal compound thin film, and after the step (b), the method further comprises a step of evacuating the atmosphere in contact with the liquid metal, wherein the thin film is formed in a reduced pressure atmosphere. The thin film forming method according to claim 7, wherein 11. The thin film comprises an insulating film, and the step (b)
After that, the method further includes a step of evacuating the atmosphere in contact with the liquid metal, and the thin film is formed by a chemical vapor deposition (CVD) method, a plasma CVD method, a sputtering method or an evaporation method in a reduced pressure atmosphere. 7. The method according to claim 7, wherein
The method of forming a thin film according to. 12. The thin film comprises a semiconductor thin film, and after the step (b), the method further comprises the step of changing the atmosphere in contact with the liquid metal to a reducing atmosphere, wherein the thin film is formed by atmospheric pressure chemical vapor deposition (CVD). Method, atmospheric pressure metalorganic CVD (MOCVD) method, or liquid phase growth method. 13. The thin film comprises a metal thin film or a metal compound thin film, and after the step (b), the method further comprises the step of changing the atmosphere in contact with the liquid metal to a reducing atmosphere. The thin film forming method according to claim 7, which is performed. 14. The thin film comprises an insulating film, and the step (b)
After that, the method further includes the step of changing the atmosphere in contact with the liquid metal to a reducing atmosphere, and the thin film is formed by atmospheric pressure chemical vapor deposition (CV).
The thin film forming method according to claim 7, wherein the thin film forming method is performed by the D) method, the vapor phase growth method, or the thermal oxidation method.