JP2000040685A - Cleaner for semiconductor substrate and its cleaning method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cleaner for a semiconductor substrate by which a clean substrate surface can be obtained without leaving a reactive product at etching on the surface of the semiconductor substrate while securing high etching rate, and its cleaning method. SOLUTION: An introduction tube 6 connected to a chamber 2 for cleaning treatment is supplied with carrier gas, and this carrier gas is introduced into the chamber 2, and also this heats a semiconductor substrate 20 placed within the chamber 2. Furthermore, the introduction tube 6 where carrier gas flows is supplied with hydrofluoric acid steam, and the hydrofluoric acid gas carried by this carrier gas is introduced into the chamber 2 after being heated before introduction into the chamber 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an apparatus and a method for cleaning a semiconductor substrate, and more particularly to an apparatus and a method for cleaning a semiconductor substrate used for removing an oxide film on a semiconductor substrate.

[0002]

2. Description of the Related Art Conventionally, for cleaning a semiconductor substrate with a vapor containing hydrofluoric acid, and in particular for substrate treatment such as removal of an oxide film, an aqueous fluoric acid solution having an azeotropic composition and a vapor of hydrofluoric acid evaporating therefrom are used. And a mixture of a mixture of anhydrous hydrofluoric acid gas and water vapor.

FIG. 9 is a view showing the configuration of a semiconductor substrate cleaning apparatus in the case of using the former azeotropic hydrofluoric acid aqueous solution. Using this cleaning apparatus, the oxide film is etched and cleaned by the following cleaning method.

[0004] A semiconductor substrate 104 is mounted on a hot plate 102 in a chamber 100 where a cleaning process is performed. A carrier gas, for example, nitrogen (N ₂ ) gas supplied from the supply port 106 into the introduction pipe 108 flows through the introduction pipe 108, and flows from the introduction port 110 into the chamber 100.
And then exhausted from the exhaust port 112.

A solution tank 114 provided between the supply port 106 and the introduction port 110 stores a hydrofluoric acid aqueous solution having an azeotropic composition that evaporates naturally at normal temperature. Therefore, the hydrofluoric acid aqueous solution naturally evaporates to form hydrofluoric acid vapor, and the solution tank 11
4 flows into the inlet tube 108 above.

Then, the above-mentioned hydrofluoric acid vapor is carried by the above-mentioned nitrogen gas supplied into the introduction pipe 108 and is introduced into the introduction port 1.
From 10 is introduced into the chamber 100. Chamber 10
In 0, the oxide film on the semiconductor substrate 104 reacts with the introduced hydrofluoric acid vapor to etch the oxide film.

In the case of performing etching cleaning using an aqueous fluoric acid solution having such an azeotropic composition, the etching rate of an oxide film on a semiconductor substrate can be changed by changing the substrate temperature of the semiconductor substrate. .

FIG. 10 is a diagram showing the structure of a semiconductor substrate cleaning apparatus when the latter is used by mixing anhydrous hydrofluoric acid gas and water vapor. Using this cleaning apparatus, the oxide film is etched and cleaned by the following cleaning method.

A semiconductor substrate 202 is placed in a chamber 200 where a cleaning process is performed. From one supply port 204, anhydrous hydrofluoric acid gas is supplied into the introduction pipe 206, and from the other supply port 208, steam is supplied into the introduction pipe 206. The introduced hydrofluoric acid gas and water vapor are mixed and flow toward the inlet 210, and are introduced into the chamber 200 from the inlet 210. In the chamber 200, the oxide film on the semiconductor substrate 202 reacts with the introduced hydrofluoric acid vapor to etch the oxide film.

When etching cleaning is performed by mixing such anhydrous hydrofluoric acid gas and water vapor, the mixing ratio of anhydrous hydrofluoric acid gas and water vapor is changed, that is, the partial pressure ratio between anhydrous hydrofluoric acid gas and water vapor is controlled. By doing so, for example, by lowering the partial pressure of water vapor, the etching rate of the oxide film can be changed.

[0011]

By the way, taking the former case of using a hydrofluoric acid solution having an azeotropic composition as an example, usually, the temperature of the semiconductor substrate is reduced to normal temperature with respect to hydrofluoric acid vapor at normal temperature (25 ° C.). When it is close, a high etching rate of about several μm / min becomes possible. However, almost the same reaction occurs in the hydrofluoric acid aqueous solution during etching, and the oxide film reacts with hydrofluoric acid to generate a reaction product on the surface of the semiconductor substrate. This reaction product can be removed by washing with water, but a watermark may be formed on the surface of the substrate.

On the other hand, when the temperature of the semiconductor substrate is sufficiently higher than the normal temperature, the above reaction product generated on the surface of the semiconductor substrate by the reaction between the oxide film and the hydrofluoric acid volatilizes. It is less likely to be generated. However, on the other hand, since the temperature difference between the semiconductor substrate and the hydrofluoric acid vapor at room temperature increases, the etching rate of the oxide film becomes as low as several angstroms / minute, which is not practically suitable for removing the oxide film. I will.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has been made in consideration of the above-described problems. In etching and cleaning an oxide film formed on a semiconductor substrate, a reaction product at the time of etching is removed while ensuring a high etching rate. An object of the present invention is to provide a semiconductor substrate cleaning apparatus and a cleaning method thereof that can obtain a clean substrate surface without leaving the surface.

[0014]

In order to achieve the above object, a semiconductor substrate cleaning apparatus according to the present invention cleans a semiconductor substrate by introducing a cleaning gas into a chamber where a cleaning process is performed. An apparatus for cleaning a semiconductor substrate, comprising: a substrate heating means for heating the semiconductor substrate placed in the chamber; and heating the cleaning gas before introducing the cleaning gas into the chamber. Gas heating means.

Further, a semiconductor substrate cleaning apparatus according to the present invention comprises a hydrofluoric acid vapor generating means for evaporating an aqueous hydrofluoric acid solution to generate hydrofluoric acid vapor, and heating the hydrofluoric acid vapor generated by the hydrofluoric acid vapor generating means. Vapor heating means for heating, a substrate heating means for heating a semiconductor substrate placed in a chamber in which a cleaning process is performed, and a hydrofluoric acid vapor heated by the hydrofluoric acid vapor heating means for introducing into the chamber. Introduction means.

Further, the apparatus for cleaning a semiconductor substrate according to the present invention provides a substrate heating means for heating a semiconductor substrate placed in a chamber where a cleaning process is performed, and generates a hydrofluoric acid vapor by evaporating a hydrofluoric acid aqueous solution. A hydrofluoric acid vapor generating means, an introducing means for introducing hydrofluoric acid vapor generated from the hydrofluoric acid vapor generating means into the chamber, and the introducing means provided between the hydrofluoric acid vapor generating means and the chamber. And hydrofluoric acid vapor heating means for heating hydrofluoric acid vapor generated from the hydrofluoric acid vapor generating means.

Further, a semiconductor substrate cleaning apparatus according to the present invention is a semiconductor substrate cleaning apparatus for cleaning a semiconductor substrate by introducing hydrofluoric acid vapor into a chamber where a cleaning process is performed. A substrate heating unit for heating the placed semiconductor substrate; and a hydrofluoric acid vapor heating unit for heating the hydrofluoric acid vapor before introducing the hydrofluoric acid vapor into the chamber.

Further, according to the present invention, there is provided an apparatus for cleaning a semiconductor substrate, comprising: a substrate heating means for heating a semiconductor substrate placed in a chamber where a cleaning process is performed; a water vapor generating means for generating water vapor; And an introduction means for introducing the steam into the chamber, and a hydrofluoric acid gas supply means for supplying anhydrous hydrofluoric gas into the introduction means between the steam generation means and the chamber.

Further, the apparatus for cleaning a semiconductor substrate according to the present invention comprises: a substrate heating means for heating a semiconductor substrate placed in a chamber where a cleaning process is performed; a water vapor generating means for generating water vapor; First introduction means for introducing into the chamber, hydrofluoric acid gas supply means for supplying anhydrous hydrofluoric acid gas, and second introduction for supplying the anhydrous hydrofluoric acid gas into the first introduction means And a hydrofluoric acid gas heating means provided in the second introducing means for heating the anhydrous hydrofluoric gas flowing through the second introducing means.

Further, a semiconductor substrate cleaning method according to the present invention is a semiconductor substrate cleaning method for cleaning a semiconductor substrate by introducing hydrofluoric acid vapor into a chamber where the cleaning process is performed. A substrate heating step of heating the placed semiconductor substrate; and a hydrofluoric acid vapor heating step of heating the hydrofluoric acid vapor before introducing the hydrofluoric acid vapor into the chamber.

Further, in the method for cleaning a semiconductor substrate according to the present invention, a step of supplying a carrier gas to an introduction pipe connected to a chamber where a cleaning process is performed, and introducing the carrier gas into the chamber; A substrate heating step of heating a semiconductor substrate placed therein; a step of supplying hydrofluoric acid vapor into an introduction pipe through which the carrier gas flows; and introducing the hydrofluoric acid vapor carried by the carrier gas into the chamber. A heating step of heating with hydrofluoric acid.

Further, the method for cleaning a semiconductor substrate according to the present invention is a method for cleaning a semiconductor substrate by introducing water vapor and anhydrous hydrofluoric acid gas into a chamber where a cleaning process is performed. A substrate heating step of heating the semiconductor substrate placed in the chamber; and a step of mixing the water vapor with anhydrous hydrofluoric acid gas to generate a mixed gas of water vapor and anhydrous hydrofluoric acid gas.

Further, in the method of cleaning a semiconductor substrate according to the present invention, a step of supplying a carrier gas to an introduction pipe connected to a chamber where a cleaning process is performed, and introducing the carrier gas into the chamber; A substrate heating step of heating the semiconductor substrate placed therein, a step of supplying water vapor into the introduction pipe through which the carrier gas flows, and supplying anhydrous hydrofluoric acid gas to the water vapor carried by the carrier gas,
Mixing the water vapor and anhydrous hydrofluoric acid gas.

Further, the method of cleaning a semiconductor substrate according to the present invention is a method of cleaning a semiconductor substrate by introducing water vapor and anhydrous hydrofluoric acid gas into a chamber where a cleaning process is performed. A substrate heating step of heating the semiconductor substrate placed in the chamber, a hydrofluoric acid gas heating step of heating the anhydrous hydrofluoric acid gas, and mixing the heated anhydrous hydrofluoric acid gas with the water vapor; Generating a mixed gas of anhydrous hydrofluoric acid gas.

Further, in the method of cleaning a semiconductor substrate according to the present invention, a step of supplying a carrier gas to an introduction pipe connected to a chamber where a cleaning process is performed, and introducing the carrier gas into the chamber; A substrate heating step of heating the semiconductor substrate placed therein, a step of supplying water vapor into the introduction pipe through which the carrier gas flows, and a heating means provided in the supply pipe connected to the introduction pipe, to supply this supply pipe. A hydrofluoric acid gas heating step of heating the passing anhydrous hydrofluoric acid gas, and a step of supplying the heated anhydrous hydrofluoric acid gas to the water vapor carried by the carrier gas and mixing the water vapor and the anhydrous hydrofluoric acid gas And

[0026]

Embodiments of the present invention will be described below with reference to the drawings. First, a semiconductor substrate cleaning apparatus according to a first embodiment of the present invention will be described.
FIG. 1 is a diagram illustrating a configuration of a semiconductor substrate cleaning apparatus according to the first embodiment.

As shown in FIG. 1, a hot plate 4 for heating a semiconductor substrate to 100 ° C. or higher is provided in a chamber 2 in which cleaning is performed. The above chamber 2
Is connected to an introduction pipe 6 for introducing a gas for cleaning into the chamber 2.
Is provided. Further, a supply port 10 for supplying a carrier gas is provided on the gas supply side of the introduction pipe 6.

Further, between the supply port 10 and the introduction port 8, a solution tank 12 for storing a solution for generating a gas for cleaning, for example, an aqueous solution of hydrofluoric acid having an azeotropic composition is provided. Have been. Between the solution tank 12 and the inlet 8,
A steam heater 14 for heating the cleaning gas to 100 ° C. immediately before introducing the cleaning gas into the chamber 2.
Is provided. Further, an exhaust port 16 for exhausting gas used for cleaning is provided at a lower portion of the chamber 2.

Next, a description will be given of a cleaning method using the above-described semiconductor substrate cleaning apparatus. First, the semiconductor substrate 20 is placed on the hot plate 4 in the chamber 2. When performing cleaning, the semiconductor substrate 20 is heated to about 100 ° C. by the hot plate 4. Subsequently, a carrier gas, for example, a nitrogen (N ₂ ) gas for carrying the gas from the solution tank 12 into the chamber 2 is supplied from the supply port 10 into the introduction pipe 6.

The solution tank 12 stores a hydrofluoric acid aqueous solution having an azeotropic composition that evaporates naturally at normal temperature. Therefore, since the hydrofluoric acid aqueous solution is kept at room temperature, it evaporates spontaneously to become hydrofluoric acid vapor and rises in the introduction pipe 6 above the solution tank 12.

Then, the hydrofluoric acid vapor is pushed out by the nitrogen gas supplied into the introduction pipe 6 and is carried into the introduction pipe 6 in which the steam heater 14 is installed. The hydrofluoric acid vapor carried to the location where the steam heater 14 is installed is heated by the steam heater 14 to 100 ° C., which is the boiling point of water, and introduced into the chamber 2 through the inlet 8.

In the chamber 2, the oxide film on the semiconductor substrate 20 placed on the hot plate 4 reacts with the introduced hydrofluoric acid vapor to etch the oxide film. At this time, as described above, the semiconductor substrate 20 and the hydrofluoric acid vapor are both heated to about 100 ° C., and since there is no temperature difference between them, the oxide film on the semiconductor substrate 20 has a thickness of 1 μm as shown in FIG. Per minute at a high etching rate. FIG. 2 is a diagram showing a change in the oxide film etching rate due to the temperature difference between the semiconductor substrate and the hydrofluoric acid vapor when the hydrofluoric acid vapor is set to 100 ° C.

At the time of this etching, the oxide film reacts with hydrofluoric acid to produce reaction products such as SiF ₄ , H ₂ SiF ₆ , and H ₂ O. However, since the temperature of the semiconductor substrate 20 is high, the reaction product volatilizes, and the semiconductor substrate 2
The above reaction product does not remain on the surface of No. 0. The gas after the etching process including the reaction products and the like in the chamber 4 is exhausted from the exhaust port 16.

As described above, since the temperature of the semiconductor substrate 20 is 100 ° C. at this time, the water generated by the etching reaction volatilizes. Therefore, since the reaction product water does not remain as particles on the semiconductor substrate 20, there is no need to perform a washing step for removing the particles. Since the washing step can be omitted, it is possible to prevent the occurrence of a watermark due to the washing step. Note that even when the semiconductor substrate 20 is washed with water, a watermark is not generated because there is no residue of a reaction product on the semiconductor substrate 20.

As described above, according to the first embodiment, when etching an oxide film formed on a semiconductor substrate by etching, a reaction product at the time of etching is removed while maintaining a high etching rate. A clean substrate surface can be obtained without leaving it on the surface. Further, since a reaction product by a reaction at the time of the etching cleaning can be volatilized, a water washing step after the etching cleaning can be omitted, and generation of a watermark due to the water washing step can be prevented.

Although the temperature of the semiconductor substrate 20 is set to 100 ° C. in the first embodiment, the temperature is not limited to 100 ° C. and may be set to 100 ° C. or higher. In this case, since the temperature difference between the semiconductor substrate and the hydrofluoric acid vapor becomes large, the etching reaction of the oxide film does not proceed as shown in FIG. However, since the hydrofluoric acid vapor itself is heated, the etching rate is high regardless of the temperature difference, so that an etching rate of about 100 Å / min can be obtained.
Therefore, it is possible to remove not only the natural oxide film on the semiconductor substrate but also other oxide films.

Although the temperature of the hydrofluoric acid vapor is heated to 100 ° C. in the first embodiment, the temperature is not limited to 100 ° C. and may be set to 100 ° C. or less. In this case, even if the temperature of the hydrofluoric acid vapor is 100 ° C. or less, the temperature of the semiconductor substrate 20 is as high as 100 ° C., so that the reaction product at the time of etching cleaning is volatilized, and the above-mentioned reaction product is deposited on the surface of the semiconductor substrate 20. Does not remain. Note that the temperature difference between the semiconductor substrate and the hydrofluoric acid vapor increases, so that the etching reaction of the oxide film does not proceed. However, the etching rate may be used within a range not lower than a desired etching rate.

Next, a modification of the first embodiment will be described. FIGS. 3, 4, and 5 are views showing Modification 1, Modification 2, and Modification 3 of the first embodiment, respectively. Modification 1 shown in FIG. 3 is different from the first embodiment in that the steam heater 14 is omitted and the hydrofluoric acid stored in the solution tank 12 is moved by the solution heater 30 provided in the solution tank 12. The aqueous solution itself is heated to 100 ° C. At this time, an azeotropic hydrofluoric acid aqueous solution at 100 ° C. is used as the hydrofluoric acid aqueous solution. The effect of the first modification is the same as that of the first embodiment.

In the second modification shown in FIG. 4, in addition to the structure of the first embodiment, a solution heater 30 provided in the solution tank 12 is used to increase the aqueous solution of hydrofluoric acid stored in the solution tank 12. It is heated to 100 ° C. and evaporated. At this time, an azeotropic hydrofluoric acid aqueous solution at 100 ° C. is used as the hydrofluoric acid aqueous solution. Regarding the effect of the second modification, in addition to the effect of the first embodiment, the vapor heater 14 provided in the introduction pipe 6 and the solution heater 30 provided in the solution tank 12 are used in combination. Thereby, the temperature of the hydrofluoric acid vapor can be more stabilized, and more stable cleaning can be performed.

In the third modification shown in FIG. 5, the semiconductor substrate 20 is heated by the infrared heater 31 provided in the chamber 2 instead of the hot plate 4 in the configuration of the first embodiment. Things. The effect of the third modification is the same as that of the first embodiment.

Next, a semiconductor substrate cleaning apparatus according to a second embodiment of the present invention will be described. FIG. 6 is a diagram illustrating a configuration of a semiconductor substrate cleaning apparatus according to the second embodiment.
As shown in FIG. 6, a hot plate 34 for heating a semiconductor substrate to 100 ° C. or higher is provided in a chamber 32 where cleaning is performed. An introduction pipe 36 for introducing a cleaning gas into the chamber 32 is connected to the chamber 32, and an introduction port 38 is provided at the connection portion. Further, a carrier gas supply port 40 for supplying a carrier gas is provided on the gas supply side of the introduction pipe 36.
Is provided.

Between the carrier gas supply port 40 and the inlet port 38, a solution tank 42 for storing a solution for generating a gas for cleaning, for example, pure water in this case, is provided. . The solution tank 42 is heated at 100 ° C.
And a solution heater 44 for heating the solution.

Further, a cleaning gas supply port 46 for supplying a cleaning gas is provided between the solution tank 42 and the inlet 38. An exhaust port 48 for exhausting gas used for cleaning is provided at a lower portion of the chamber 32.
Is provided.

Next, a description will be given of a cleaning method using the above-described semiconductor substrate cleaning apparatus. First, the semiconductor substrate 50 is placed on the hot plate 34 in the chamber 32. When cleaning is performed, the semiconductor substrate 50 is placed on the hot plate 3.
4 to about 100 ° C. Subsequently, a carrier gas, for example, a nitrogen (N ₂ ) gas for carrying the gas discharged from the solution tank 42 into the chamber 32 is supplied to the carrier gas supply port 4.
It is supplied into the introduction pipe 36 from 0.

The solution tank 42 stores pure water. The pure water is heated by the solution heater 44 and boiled, and turns into steam and flows out into the introduction pipe 36 above the solution tank 42. Then, the steam is pushed out by the nitrogen gas supplied into the introduction pipe 36 and flows out toward the introduction port 38.

An anhydrous hydrofluoric acid gas is supplied from the cleaning gas supply port 46 into the introduction pipe 36. This hydrofluoric anhydride gas is mixed with the above-mentioned steam and flows in the direction of the inlet 38.
The water is introduced into the chamber 32 together with the water vapor from the inlet 38. As a result, about 100
This means that hydrofluoric acid gas and water vapor heated to ° C. were introduced.

In the chamber 32, the semiconductor substrate 50
Is heated to about 100 ° C. by the hot plate 34, and the oxide film on the semiconductor device 50 reacts with the introduced hydrofluoric acid gas and water vapor to etch the oxide film. At this time, as described above, the semiconductor substrate 50
And the hydrofluoric acid gas and water vapor are both heated to about 100 ° C., and there is no temperature difference between them, so that the oxide film on the semiconductor substrate 50 is etched at a high etching rate.

As shown in FIG. 7, the etching rate of the oxide film can be arbitrarily selected by lowering the partial pressure of water vapor at a partial pressure ratio between hydrofluoric anhydride gas and water vapor.

During this etching, the oxide film reacts with hydrofluoric acid to produce reaction products such as SiF ₄ , H ₂ SiF ₆ and H ₂ O. However, since the temperature of the semiconductor substrate 50 is high as in the first embodiment, the reaction product volatilizes, and the reaction product does not remain on the surface of the semiconductor substrate 50. The gas after the etching process including the reaction product and the like in the chamber 32 is exhausted from the exhaust port 48.

As described above, since the temperature of the semiconductor substrate 50 is 100 ° C. at this time, the water generated by the etching reaction volatilizes. Therefore, since the reaction product water does not remain as particles on the semiconductor substrate 50, there is no need to perform a water washing step for removing the particles. Since this washing step can be omitted, the occurrence of a watermark due to the washing step can be prevented. Note that even when the semiconductor substrate 50 is washed with water, no watermark is generated because there is no residue of a reaction product on the semiconductor substrate 50.

According to the second embodiment described above, when etching an oxide film formed on a semiconductor substrate by etching, a reaction product during the etching is removed while maintaining a high etching rate. A clean substrate surface can be obtained without leaving it on the surface. Further, since a reaction product by a reaction at the time of the etching cleaning can be volatilized, a water washing step after the etching cleaning can be omitted, and generation of a watermark due to the water washing step can be prevented.

Note that, as in the first embodiment, the temperature of the semiconductor substrate 50 is set to 1 in the second embodiment.
Although the temperature was set to 00 ° C., the temperature is not limited to this, and may be set to 100 ° C. or more. In this case, since the temperature difference between the semiconductor substrate and the hydrofluoric acid vapor becomes large, the etching reaction of the oxide film does not proceed as shown in FIG. However, since the hydrofluoric acid vapor itself is heated, the etching rate is high regardless of the temperature difference, so that an etching rate of about 100 Å / min can be obtained. Therefore, it is possible to remove not only the natural oxide film on the semiconductor substrate but also other oxide films.

In the second embodiment, the temperatures of the hydrofluoric acid gas and the steam are heated to 100 ° C., but the temperature is not limited to this and may be set to 100 ° C. or lower. In this case, since the temperature of the semiconductor substrate 50 is as high as 100 ° C. even when the temperature of the hydrofluoric acid gas and the water vapor is 100 ° C. or less, the reaction product at the time of etching and cleaning volatilizes, and the surface of the semiconductor substrate 50 has the above reaction. No product remains. Note that the temperature difference between the semiconductor substrate and the hydrofluoric acid gas and water vapor increases, so that the etching reaction of the oxide film does not proceed. However, the oxide film may be used in a range not too lower than a desired etching rate.

Next, a modified example of the second embodiment will be described. FIG. 8 is a diagram illustrating a modification of the second embodiment. In this modification, the cleaning gas supply port 46 provided between the solution tank 42 and the inlet 38 in the configuration of the second embodiment is replaced with the cleaning gas supply port 52 shown in FIG. Position, and the cleaning gas supply port 5
A gas heater 54 for heating the anhydrous hydrofluoric acid gas supplied from the inlet 38 is provided between the inlet 2 and the inlet 38.

Therefore, the anhydrous hydrofluoric acid gas supplied from the cleaning gas supply port 52 is heated to 100 ° C. by the gas heater 54, and the anhydrous hydrofluoric acid gas is mixed with water vapor, and is mixed with the water vapor through the inlet 38. It is introduced into the chamber 32. In the chamber 32, the semiconductor substrate 50 is heated to 100 ° C. by the hot plate 34. The oxide film on the semiconductor device 50 reacts with the introduced hydrofluoric acid gas and water vapor to etch the oxide film. Is performed.

The effect of this modification is similar to the effect of the second embodiment, except that the gas heater 54 provided in the introduction pipe 36 and the solution heater 44 provided in the solution tank 42 are used in combination. By doing so, the temperatures of hydrofluoric acid gas and water vapor can be stabilized, and more stable cleaning can be performed.

Further, in the configuration of the second embodiment, the semiconductor substrate 50 may be heated by an infrared heater provided in the chamber 32 instead of the hot plate 34.

[0058]

As described above, according to the present invention, when an oxide film formed on a semiconductor substrate is etched and cleaned,
It is possible to provide a semiconductor substrate cleaning apparatus and a cleaning method thereof that can obtain a clean substrate surface without leaving a reaction product at the time of etching on the semiconductor substrate surface while securing a high etching rate.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of a semiconductor substrate cleaning apparatus according to a first embodiment.

FIG. 2 is a diagram showing a change in an oxide film etching rate due to a temperature difference between a semiconductor substrate and hydrofluoric acid vapor when hydrofluoric acid vapor is set to 100 ° C.

FIG. 3 is a diagram illustrating a configuration of a cleaning apparatus according to a first modification of the first embodiment.

FIG. 4 is a diagram illustrating a configuration of a cleaning apparatus according to a modification 2 of the first embodiment.

FIG. 5 is a diagram illustrating a configuration of a cleaning apparatus according to Modification 3 of the first embodiment.

FIG. 6 is a diagram illustrating a configuration of a semiconductor substrate cleaning apparatus according to a second embodiment.

FIG. 7 is a diagram showing a change in an oxide film etching rate depending on a partial pressure ratio between hydrofluoric acid gas and water vapor when a semiconductor substrate is set at 100 ° C.

FIG. 8 is a diagram illustrating a configuration of a cleaning apparatus according to a modification of the second embodiment.

FIG. 9 is a view showing the configuration of a conventional cleaning apparatus in the case of using a hydrofluoric acid aqueous solution having an azeotropic composition.

FIG. 10 is a diagram showing a configuration of a conventional cleaning apparatus when a mixture of anhydrous hydrofluoric acid gas and water vapor is used.

[Explanation of symbols]

 2, 32: Chamber 4, 34: Hot plate 6, 36: Inlet tube 8, 38: Inlet 10: Supply port 12, 42: Solution tank 14: Steam heater 16, 48: Exhaust port 20, 50: Semiconductor substrate 30, 44: Solution heater 31: Infrared heater 40: Carrier gas supply port 46: Cleaning gas supply port 52: Cleaning gas supply port 54: Gas heater

Claims (20)

[Claims] 1. A semiconductor substrate cleaning apparatus for cleaning a semiconductor substrate by introducing a cleaning gas into a chamber where a cleaning process is performed, wherein the substrate heating means heats the semiconductor substrate placed in the chamber. And a gas heating means for heating the cleaning gas before introducing the cleaning gas into the chamber. 2. A hydrofluoric acid vapor generating means for evaporating a hydrofluoric acid aqueous solution to generate hydrofluoric acid vapor, a hydrofluoric acid vapor heating means for heating hydrofluoric acid vapor generated by the hydrofluoric acid vapor generating means, and a cleaning process. Substrate heating means for heating a semiconductor substrate placed in a chamber to be performed, and introduction means for introducing the hydrofluoric acid vapor heated by the hydrofluoric acid vapor heating means into the chamber. Cleaning equipment for semiconductor devices. 3. A substrate heating means for heating a semiconductor substrate placed in a chamber where a cleaning process is performed; a hydrofluoric acid vapor generating means for evaporating a hydrofluoric acid aqueous solution to generate hydrofluoric acid vapor; Introducing means for introducing the hydrofluoric acid vapor generated from the generating means into the chamber; and providing the hydrofluoric acid vapor generated from the hydrofluoric acid vapor generating means provided in the introducing means between the hydrofluoric acid vapor generating means and the chamber. A cleaning device for a semiconductor device, comprising: hydrofluoric acid vapor heating means for heating an acid vapor. 4. A semiconductor substrate cleaning apparatus for cleaning a semiconductor substrate by introducing a hydrofluoric acid vapor into a chamber in which a cleaning process is performed, wherein: a substrate heating means for heating the semiconductor substrate placed in the chamber; And a hydrofluoric acid vapor heating means for heating the hydrofluoric acid vapor before introducing the hydrofluoric acid vapor into the chamber. 5. A substrate heating means for heating a semiconductor substrate placed in a chamber where a cleaning process is performed; a water vapor generating means for generating water vapor; and connected to the chamber to introduce the water vapor into the chamber. And a hydrofluoric acid gas supply means for supplying anhydrous hydrofluoric gas into the introduction means between the water vapor generation means and the chamber. 6. A substrate heating unit for heating a semiconductor substrate placed in a chamber where a cleaning process is performed, a steam generation unit for generating steam, and a first introduction for introducing the steam into the chamber. Means, hydrofluoric acid gas supply means for supplying anhydrous hydrofluoric acid gas, second introducing means for supplying the anhydrous hydrofluoric acid gas into the first introducing means, and provided in the second introducing means. And a hydrofluoric acid gas heating means for heating the anhydrous hydrofluoric acid gas flowing through the second introduction means. 7. The apparatus according to claim 2, wherein said substrate heating means heats said semiconductor substrate to about 100 ° C. or higher, and said hydrofluoric acid vapor heating means heats said hydrofluoric acid vapor to about 100 ° C. The apparatus for cleaning a semiconductor substrate according to any one of items 3 and 4. 8. The cleaning of a semiconductor substrate according to claim 2, wherein the hydrofluoric acid vapor is hydrofluoric acid vapor evaporated from an aqueous fluoric acid solution having an azeotropic composition. apparatus. 9. The semiconductor device according to claim 5, wherein said substrate heating means heats said semiconductor substrate to approximately 100 ° C. or higher.
3. The cleaning apparatus for a semiconductor substrate according to claim 1. 10. The method according to claim 6, wherein said substrate heating means heats said semiconductor substrate to about 100 ° C. or more, and said hydrofluoric acid gas heating means heats said anhydrous hydrofluoric acid gas to about 100 ° C. A cleaning device for a semiconductor substrate according to the above. 11. A semiconductor substrate cleaning method for cleaning a semiconductor substrate by introducing hydrofluoric acid vapor into a chamber in which a cleaning process is performed, wherein the semiconductor substrate placed in the chamber is heated; A step of heating the hydrofluoric acid vapor before introducing the hydrofluoric acid vapor into the chamber. 12. A step of supplying a carrier gas to an introduction pipe connected to a chamber where a cleaning process is performed, introducing the carrier gas into the chamber, and heating a semiconductor substrate placed in the chamber. Supplying a hydrofluoric acid vapor into an introduction pipe through which the carrier gas flows; and heating the hydrofluoric acid vapor carried by the carrier gas before introducing the hydrofluoric acid vapor into the chamber. For cleaning semiconductor substrates. 13. The step of heating the semiconductor substrate comprises heating the semiconductor substrate to about 100 ° C. or higher, and the step of heating the hydrofluoric acid vapor comprises heating the hydrofluoric acid vapor to about 100 ° C. The method for cleaning a semiconductor substrate according to claim 11. 14. The method for cleaning a semiconductor substrate according to claim 11, wherein the hydrofluoric acid vapor is hydrofluoric acid vapor evaporated from a hydrofluoric acid aqueous solution having an azeotropic composition. 15. A semiconductor substrate cleaning method for cleaning a semiconductor substrate by introducing water vapor and anhydrous hydrofluoric acid gas into a chamber where a cleaning process is performed, wherein the semiconductor substrate placed in the chamber is heated. And a step of mixing the water vapor with anhydrous hydrofluoric acid gas to generate a mixed gas of water vapor and anhydrous hydrofluoric acid gas. 16. A step of supplying a carrier gas to an introduction pipe connected to a chamber in which a cleaning process is performed, introducing the carrier gas into the chamber, and heating a semiconductor substrate placed in the chamber. Supplying water vapor into the introduction pipe through which the carrier gas flows, and supplying an anhydrous hydrofluoric acid gas to the water vapor carried by the carrier gas, and mixing the water vapor and the anhydrous hydrofluoric acid gas. A method for cleaning a semiconductor substrate, comprising: 17. A method for cleaning a semiconductor substrate by introducing water vapor and anhydrous hydrofluoric acid gas into a chamber where a cleaning process is performed, wherein the semiconductor substrate placed in the chamber is heated. Heating the anhydrous hydrofluoric acid gas; and mixing the heated anhydrous hydrofluoric acid gas with the steam.
Producing a mixed gas of water vapor and anhydrous hydrofluoric acid gas. 18. A step of supplying a carrier gas to an introduction pipe connected to a chamber where a cleaning process is performed, introducing the carrier gas into the chamber, and heating a semiconductor substrate placed in the chamber. A heating step, a step of supplying water vapor into the introduction pipe through which the carrier gas flows, and a step of heating the anhydrous hydrofluoric acid gas passing through the supply pipe by heating means provided on the supply pipe connected to the introduction pipe. Supplying the heated anhydrous hydrofluoric acid gas to the water vapor carried by the carrier gas, and mixing the water vapor and the anhydrous hydrofluoric acid gas. 19. The method for cleaning a semiconductor substrate according to claim 15, wherein the step of heating the semiconductor substrate heats the semiconductor substrate to approximately 100 ° C. or higher. 20. The method according to claim 20, wherein the step of heating the semiconductor substrate heats the semiconductor substrate to about 100 ° C. or higher, and the step of heating the hydrofluoric acid gas heats the anhydrous hydrofluoric acid gas to about 100 ° C. 19. The method for cleaning a semiconductor substrate according to claim 17, wherein