JP2013161954A - Cvd device and cleaning method for cvd device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a convenient cleaning method for deposits in a reaction chamber of a CVD device.SOLUTION: There is provided a cleaning method for removing water-soluble depositions produced as a by-product in a CVD device 100, the cleaning method including gasifying and removing condensed water including dissolved water-soluble deposits outside a reaction chamber by supplying overheating steam into the reaction chamber 10, dissolving the water-soluble deposits in the condensed water condensed in the reaction chamber 10, and evacuating the reaction chamber 10.

Description

  The present invention relates to a CVD apparatus and a CVD apparatus cleaning method.

In a CVD (Chemical Vapor Deposition) system that activates a gas containing raw material material of the target thin film into plasma, etc., and forms a film on the substrate by chemical reaction, it adheres and deposits on the surfaces of chamber inner walls and electrodes The produced by-product causes particles that cause manufacturing defects due to peeling and dropping, and thus needs to be efficiently removed. In addition, the by-product often contains the same component as the source gas, which affects the accuracy of film thickness control during film formation. Therefore, a cleaning operation for removing by-products is often performed after the film forming operation.
Conventionally, for example, as described in Patent Document 1, a cleaning method has been known in which fluorine gas is converted into plasma, reacted with by-products, and gasified to be removed.

JP 2004-39740 A

  However, the cleaning method described in Patent Document 1 has a problem that the fluorine component remains in the chamber after cleaning, which may affect the subsequent film formation. Specifically, when the oxide film is deposited on the substrate, the remaining fluorine component is mixed into the oxide film, and the characteristics (for example, insulation) as the oxide film are deteriorated.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following application examples or forms.

  Application Example 1 A CVD apparatus according to this application example is a CVD apparatus that supplies a reaction gas from a film forming material supply chamber into a reaction chamber and forms a film on the surface of a product disposed in the reaction chamber, After water-soluble deposits are generated in the reaction chamber, superheated steam is supplied from the superheated steam supply chamber into the reaction chamber without placing the product in the reaction chamber, and the superheated steam is converted into the reaction chamber. The water-soluble deposit is dissolved in the condensed water condensed in the chamber, and the reaction chamber is evacuated by a vacuum exhaust pump to gasify the condensed water and remove the water-soluble deposit outside the chamber. It is characterized by doing.

  According to this application example, the water-soluble deposit is dissolved in the condensed water condensed in the superheated steam supplied into the reaction chamber, and the chamber is evacuated to gasify the dissolved water-soluble deposit to react. It can be removed out of the chamber. As a result, water-soluble deposits can be removed from the reaction chamber without using fluorine gas. Since no fluorine gas is used, the fluorine component does not remain in the reaction chamber after cleaning, and the problem that the remaining fluorine component affects subsequent film formation is eliminated.

  [Application Example 2] A cleaning method of a CVD apparatus according to this application example is a CVD apparatus for supplying a reaction gas into a reaction chamber and forming a thin film on a surface of a product arranged in the reaction chamber. A cleaning method for removing water-soluble deposits generated in the reaction chamber to the outside of the reaction chamber without being disposed in the reaction chamber, the first exhausting step for evacuating the reaction chamber; A steam supply step of supplying superheated steam into the evacuated reaction chamber, a deposit dissolving step of dissolving the water-soluble deposit in condensed water condensed in the reaction chamber, and evacuating the reaction chamber, And a second exhausting step of gasifying the condensed water to remove the water-soluble deposits out of the reaction chamber.

  According to this application example, the cleaning method includes a step of evacuating the reaction chamber, a step of supplying superheated steam to the evacuated reaction chamber, and dissolving water-soluble deposits in condensed water condensed in the reaction chamber. And evacuating the reaction chamber and gasifying the condensed water to remove water-soluble deposits outside the reaction chamber. The superheated steam can be efficiently introduced into the reaction chamber by evacuating the reaction chamber and then supplying the superheated steam. Thereby, the water-soluble deposit produced | generated as a by-product can be removed, without using fluorine gas. Since no fluorine gas is used, the fluorine component does not remain in the reaction chamber after cleaning, and the problem that the remaining fluorine component affects subsequent film formation is eliminated.

  Application Example 3 In the CVD apparatus cleaning method according to the application example, the pressure in the reaction chamber in the first exhaust process is 1 Pa or less, and the pressure of the superheated steam in the steam supply process is 30000 Pa or more. , 60000 Pa or less, the temperature in the reaction chamber in the deposit dissolution step is 40 ° C. or more and 100 ° C. or less, and the pressure in the reaction chamber in the deposit dissolution step is 5000 Pa or more and 15000 Pa or less. In the deposit dissolution step, the standing time is 5 minutes or more and 30 minutes or less, and the pressure in the reaction chamber in the second exhaust step is 1 Pa or less.

  According to this application example, the water-soluble deposit produced as a by-product can be dissolved in water and gasified and removed efficiently within the range of these conditions. Water-soluble deposits produced as products can be removed. Therefore, the fluorine component does not remain in the reaction chamber after cleaning, and the problem that the remaining fluorine component affects subsequent film formation is eliminated.

Schematic of a CVD apparatus. The flowchart of the cleaning method. The schematic diagram which shows the mechanism of a by-product removal.

  DESCRIPTION OF EMBODIMENTS Embodiments embodying the present invention will be described below with reference to the drawings. The following is one embodiment of the present invention and does not limit the present invention. In the following drawings, the scale may be different from the actual scale for easy understanding.

(Embodiment 1)
First, a cleaning method for the CVD apparatus 100 according to the first embodiment will be described. Note that the cleaning method according to the present embodiment does not depend on a CVD method such as thermal CVD or plasma CVD, and therefore a description of a mechanism and a method related to film formation is omitted.
FIG. 1 is a schematic diagram of a CVD apparatus 100. The CVD apparatus 100 includes a film forming mechanism (not shown), a reaction chamber 10, a film forming material supply chamber 20, a superheated steam supply chamber 30, a vacuum exhaust pump (not shown), and the like.

The reaction chamber 10 is provided with a film formation mechanism inside, and constitutes a reaction space in which a deposited film is formed (hereinafter referred to as “film formation”) on the substrate surface disposed inside by the supplied reaction gas (film formation gas). ing. The reaction chamber 10 is sealed by a main valve Vm, an inert gas introduction valve Vg, a valve V1, a valve V3, and the like. Further, a heating / cooling mechanism (not shown) and a vacuum gauge 11 are provided. The vacuum gauge 11 is a diaphragm vacuum gauge and measures the internal pressure of the reaction chamber 10.
The vacuum pump is in communication with the reaction chamber 10 via the main valve Vm.

The film forming raw material supply chamber 20 communicates with the reaction chamber 10 via the valve V1 and the valve V2. The film forming material supply chamber 20 includes a heating / cooling mechanism (not shown), vaporizes the film forming material 2 accommodated therein, and supplies the film forming material 2 as a film forming gas to the reaction chamber 10. A vacuum gauge 21 is provided between the valve V1 and the valve V2. The vacuum gauge 21 is a diaphragm type vacuum gauge and measures the pressure of the film forming gas supplied to the reaction chamber 10.
The film-forming raw material 2 is a water-soluble film-forming raw material, and for example, a water-soluble organic material having a silane coupling group is used.

  The superheated steam supply chamber 30 communicates with the reaction chamber 10 via a valve V3. The superheated steam supply chamber 30 includes a heating / cooling mechanism (not shown), vaporizes the pure water 3 accommodated therein, and supplies it to the reaction chamber 10 as superheated steam. The superheated steam means steam obtained by further heating 100 ° C. steam (saturated steam) under atmospheric pressure.

  In the CVD apparatus 100 configured as described above, during the film forming process, the film forming raw material 2 and the reaction product adhere to and deposit on the inner wall of the reaction chamber 10 and the surface of the film forming mechanism as by-products. If the film forming process is repeated without removing this by-product, the deposition thickness of the by-product gradually increases and eventually peels off due to its own weight and stress, and falls and floats as foreign matter (particles) in the reaction chamber 10. It will be. This foreign matter causes a manufacturing defect and makes it impossible to produce a high-quality film, and it is necessary to remove and clean by-products as needed.

FIG. 2 shows a flowchart of the cleaning method.
FIG. 3 shows a schematic diagram of the mechanism of by-product removal.
The cleaning method in the present embodiment will be described with reference to FIGS. Note that the cleaning is performed after the film formation process is completed and the substrate is taken out from the CVD apparatus 100.

  First, as the first exhaust process, the inert gas introduction valve Vg, the valve V1 and the valve V3 are closed, the vacuum exhaust pump is operated, the main valve Vm is opened, and the residual gas in the reaction chamber 10 is exhausted, and the reaction chamber is exhausted. The internal pressure of 10 is set to 1 Pa or less (step S1). At this time, since the film forming process is completed, the film forming raw material 2 and its reaction product are formed as by-products on the inner wall of the reaction chamber 10 and the surface of the film forming mechanism as shown in FIG. Adhering and depositing.

  Next, as a steam charging process, the main valve Vm is closed, and the superheated steam supply chamber 30 is heated until the water vapor pressure of the pure water 3 reaches about 50000 Pa to generate superheated steam (step S2), and the valve V3 is gradually turned on. Open and superheated steam is introduced into the reaction chamber 10 (step S3). The water-soluble deposit produced as a by-product is exposed to superheated steam as shown in FIG.

  Next, the vapor pressure in the reaction chamber 10 is kept at about 10,000 Pa at about 100 ° C., the valve V3 is closed, and the mixture is left for about 10 minutes (step S4). At this time, as shown in FIG. 3 (c), it is generated as a by-product in the superheated steam (water) that is adsorbed and condensed on the inner wall of the reaction chamber 10 or the surface of the film forming mechanism during the period from the introduction of the superheated steam. The formed water-soluble deposit dissolves (deposit dissolution step).

  Next, the vacuum exhaust pump is operated, the main valve Vm is opened, and water in which the superheated steam and water-soluble deposits in the reaction chamber 10 are dissolved is gasified and exhausted (step S5, second exhaust process). Evacuation is continued until the internal pressure of the reaction chamber 10 becomes 1 Pa or less to complete the cleaning. As shown in FIG. 3D, the dissolved water-soluble deposit is gasified and exhausted. Even if the deposit is difficult to gasify (sublimate) if it remains solid, it can be easily gasified (evaporated) if dissolved as a liquid. Since the amount of condensed water is large compared to the amount of deposits, the evaporated water can be efficiently discharged out of the chamber as a carrier gas. In addition, superheated steam is supplied into the chamber, so that the deposits are efficient. Can be dissolved well.

As described above, according to the CVD apparatus cleaning method of the present embodiment, the following effects can be obtained.
The water-soluble deposit generated as a by-product is dissolved in the superheated vapor adsorbed and condensed in the chamber, and the chamber is evacuated to gasify and remove the dissolved water-soluble deposit. Thereby, the water-soluble deposit produced | generated as a by-product can be removed, without using fluorine gas. Since no fluorine gas is used in the cleaning process, the fluorine component does not remain in the chamber after cleaning, and the problem that the remaining fluorine component affects the subsequent film formation is eliminated.

Moreover, since an expensive incidental facility for using fluorine gas or the like is not required, the cleaning process can be configured at a lower cost.
As a result, a cheaper and simpler film forming apparatus and film forming process can be realized.

(program)
A CVD apparatus that forms a deposited film on a substrate surface using a water-soluble film forming raw material is not limited to the CVD apparatus 100, and may include a program that causes the cleaning apparatus described above to function when cleaning the CVD apparatus. it can. Specifically, it is a program that senses the temperature and pressure of each chamber and controls each heating and cooling mechanism and each valve. By performing cleaning using this program, water-soluble deposits generated as by-products can be removed without using fluorine gas. Therefore, the fluorine component does not remain in the chamber after cleaning, and a CVD apparatus free from the problem that the remaining fluorine component affects subsequent film formation can be provided.

  DESCRIPTION OF SYMBOLS 2 ... Film-forming raw material, 3 ... Pure water, 10 ... Reaction chamber, 11, 21 ... Vacuum gauge, 20 ... Film-forming raw material supply chamber, 30 ... Superheated steam supply chamber, 100 ... CVD apparatus, V1-V3, Vg, Vm …valve.

Claims (3)

A CVD apparatus for supplying a reaction gas from a film forming raw material supply chamber into a reaction chamber and forming a film on the surface of a product disposed in the reaction chamber,
After water-soluble deposits are generated in the reaction chamber,
In a state where the product is not disposed in the reaction chamber, superheated steam is supplied into the reaction chamber from a superheated steam supply chamber,
Dissolving the water-soluble deposits in condensed water in which the superheated vapor has condensed in the reaction chamber;
A CVD apparatus, wherein the reaction chamber is evacuated by a vacuum evacuation pump to gasify the condensed water and remove the water-soluble deposits outside the chamber. In a CVD apparatus that supplies a reaction gas into a reaction chamber and deposits a thin film on the surface of the product placed in the reaction chamber, the product is generated in the reaction chamber without placing the product in the reaction chamber. A cleaning method for removing the water-soluble deposits out of the reaction chamber,
A first evacuation step for evacuating the reaction chamber;
A steam supply step of supplying superheated steam into the evacuated reaction chamber;
A deposit dissolving step of dissolving the water-soluble deposit in condensed water condensed in the reaction chamber;
A CVD apparatus cleaning method comprising: a second evacuation step of evacuating the reaction chamber and gasifying the condensed water to remove the water-soluble deposits outside the reaction chamber. The pressure in the reaction chamber by the first exhaust process is 1 Pa or less,
The pressure of the superheated steam in the steam supply step is 30000 Pa or more and 60000 Pa or less,
The temperature in the reaction chamber in the deposit dissolution step is 40 ° C. or more and 100 ° C. or less,
The pressure in the reaction chamber in the deposit dissolving step is 5000 Pa or more and 15000 Pa or less,
The standing time in the deposit dissolving step is 5 minutes or more and 30 minutes or less,
3. The CVD apparatus cleaning method according to claim 2, wherein the pressure in the reaction chamber in the second evacuation step is 1 Pa or less. 4.

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