JP2000290774A - Method for preventing adhesion of film forming material and vacuum treating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for preventing the adhesion of a film forming material capable of preventing the adhesion of a film forming material to the non-film forming region in an object to be film-formed without exerting influence on the film formed on the surface of the object to be film-formed. SOLUTION: At the time of forming a film on the object 3 to be film-formed by a CVD method in a vacuum, on the surface of the non-film forming region 3b in the object 3 to be film-formed, gas 9 for preventing deposition contg. inear components is adsorbed. At the time of the film formation, the gas 9 for preventing deposition is constantly fed to the surface of the non-film forming region 3b in the object 3 to be film-formed. As the gas 9 for preventing deposition, the one obtd. by adding inert gas with an organic compd. such as isopropyl alcohol is desirably used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for preventing a film from adhering to a part where a film is not originally supposed to be formed when a film forming process such as a chemical vapor deposition (CVD) method is performed.

[0002]

2. Description of the Related Art In general, when a film is formed by a CVD method, a film-forming object such as a wafer has a portion to which the film must not be attached. For example, when a film formation target is a wafer, the peripheral portion and the back surface of the wafer correspond to this. The reason is that when these parts come into contact with a transport cassette, a film forming apparatus, an inspection / measurement device, etc., the film is peeled off or the film adheres to these devices, and the surrounding atmosphere and the devices are reduced. This is because there is a risk of contamination.

Conventionally, a method for preventing the film from adhering to the periphery of a film-forming object such as a wafer includes the following methods. A method in which a plate-like member (referred to as a cover, a mask, or the like) is adhered to the above.

(2) A method of introducing an inert gas to the back or periphery of a film-forming target to prevent the film-forming gas from flowing around or around the wafer.

(3) A method in which an organic compound having active electrons that reacts with a metal halide is added to a source gas to a gas introduced to the back surface or the periphery of a film-forming target.

Have been proposed (for example, Japanese Patent No.
03909, JP-A-4-233221, and Japanese Patent No. 2748881).

[0007]

However, such a conventional technique has the following problems.
That is, in the case of a method in which a plate-like member is adhered to a portion where a film is not to be attached, as in the method (1), the film is continuously formed on the surface of the plate-like member and the film formation target. Therefore, for example, when the plate-shaped member is moved to carry out the film formation target from the chamber, the film is broken, and thereby, the necessary film on the surface of the film formation target is peeled off. And there is a disadvantage that dust is generated.

In the method (2), the inert gas is caused to flow in the opposite direction to the film-forming gas so that the gases collide with each other, so that the gas intrudes into the vicinity of the surface of the portion where film deposition is not originally desired. According to this method, the disadvantages as in the method (1) do not occur, but in order to appropriately control the collision between the gases, the inert gas is formed around the film formation target. It is necessary to precisely set the dimensions of the gas flow path, and in this method, the setting of conditions such as the pressure and flow rate of the inert gas is very delicate. As a result, there is a limit to industrially using the method (2).

The specific disadvantages of the above method (2) are as follows. In other words, in order to prevent the deposition gas from entering by the flow of the inert gas, it is necessary that the number of collisions between the gases is large. For this purpose, the gas flow path must be extremely narrow or the inert gas The pressure must be high.

However, such an apparatus is difficult to design and manufacture, and the pressure of the main process cannot be largely changed by the added inert gas, so that the applicable process pressure is limited. Become.

If the amount of the inert gas introduced is too large, the flow of the film forming gas is disturbed in the process space.
The thickness of the portion where the film is desired to be formed becomes thin.

On the other hand, in the case of a method in which an organic compound having an active electron which reacts with a metal halide is added to the raw material gas as in the method (3), halogen is removed from the metal halide by the active electron. Therefore, there is a problem in that the remaining metal is deposited on the surface of the film formation target in the vicinity of the portion where the film is not formed.

Further, in this method, since a large amount of an organic compound is introduced, the influence is also exerted on a portion where a film is to be formed, and the thickness of the film at the peripheral portion of the film-forming object is reduced. There are also problems.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and does not affect the film formed on the surface of the film formation object. It is an object of the present invention to provide a method for preventing deposition of a film-forming material and a vacuum processing apparatus capable of preventing the film-forming material from being adhered to a region where no film is formed.

[0015]

Means for Solving the Problems The inventors of the present invention have made intensive efforts to solve the above-mentioned problems, and as a result, a predetermined gas is adsorbed in a region where a film-forming object is not formed, thereby forming a film-forming object. The present inventors have found that it is possible to prevent deposition of a film-forming material on a region where a film-forming object is not formed without affecting a film formed on the surface of the object, and have completed the present invention.

The present invention has been made based on such findings.
As described in claim 1, when performing film formation on a film formation target in a vacuum, the surface of a non-film formation region of the film formation target has an anti-wear component containing an inert component. This is a method for preventing deposition of a film-forming material, which comprises adsorbing gas.

According to the first aspect of the present invention, when a film is formed on a film-forming object in a vacuum, a gas for preventing deposition is adsorbed on the surface of the non-film-forming region of the film-forming object. Since the surface is covered with the inert material, the reactive substance cannot be adsorbed in the non-film formation region, and the film formation in this region is hindered.

As described above, according to the present invention, since the gas is adsorbed on the surface of the object to be processed, a considerably small amount of gas is required as compared with the prior art in which the gases collide or react with each other in the film forming space. It is possible to reliably prevent the deposition material from adhering to the non-deposition region of the processing target.

According to the present invention, the film formed on the surface of the object to be film-formed is hardly affected by the inert adsorbed gas component, and a high-quality film can be formed.

In this case, as in the second aspect of the present invention,
In the first aspect of the present invention, it is also effective to constantly supply the anti-wear gas to the surface of the non-film formation region of the film formation target during the film formation.

The gas for prevention once adsorbed on the surface of the non-film-forming region of the film-forming object is separated from the surface of the film-forming object after a predetermined time elapses.
Since the gas for preventing deposition is constantly supplied to the surface of the non-film-forming region of the film-forming object, it is ensured that the film-forming material adheres to the non-film-forming region of the processing object during the film-forming. Can be prevented.

According to a third aspect of the present invention, in the invention of any one of the first and second aspects, the gas for preventing deposition has a molecular weight of 60 or more and its raw material is a liquid at room temperature. It is also effective to use a material containing an adsorbed gas component generated from the organic compound.

According to the third aspect of the present invention, it is possible to reliably prevent the deposition material from adhering to the surface of the non-deposition region of the deposition target with a smaller amount of gas, and to further reduce the amount of the adsorbed gas component. Since the raw material is a liquid, there is an advantage that handling is easy.

Further, as in the invention according to claim 4, C
When a film is formed on the surface of a film formation target by the VD method, it is also effective to adsorb a predetermined anti-wear gas to the surface of the non-film formation region of the film formation target.

According to the fourth aspect of the present invention, there is provided a CVD method in which the film-forming object does not adhere to the surface of the non-film-forming region of the film-forming object. In particular, in the thermal CVD method, the object to be processed becomes a high temperature of several hundred degrees Celsius or more during the film forming process, and the adsorbed gas component is easily separated from the surface of the object to be formed.
As in the second aspect of the present invention, it is preferable that an anti-wear gas is constantly supplied to the surface of the non-film-forming region of the film-forming target.

On the other hand, the invention according to claim 5 comprises a vacuum processing tank capable of accommodating a film-forming object to be processed, and a deposition-inhibiting gas introducing means for introducing a predetermined anti-wear gas into the vacuum processing tank. A deposition gas supply unit for supplying the deposition-inhibiting gas introduced by the gas introduction unit to the surface of the non-deposition region of the deposition target.

According to the fifth aspect of the present invention, the above-described methods of the first to fourth aspects can be easily and efficiently performed, and a vacuum processing apparatus having a simple configuration can be obtained.

In this case, as in the sixth aspect of the present invention,
In the invention according to claim 5, the anti-adhesion gas introducing means may include an anti-adhesion gas generating means for generating an anti-adhesion gas by generating bubbles in a raw material liquid of the anti-adhesion gas. It is effective.

According to the sixth aspect of the present invention, since the gas for preventing deposition is generated by generating bubbles in the raw material liquid of the gas for preventing deposition, the introduction amount of the gas for preventing deposition is reduced. Fine adjustment can be easily performed, and thereby film formation can be performed under optimal conditions.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a method for preventing deposition of a film-forming material and a vacuum processing apparatus according to the present invention will be described below in detail with reference to the drawings. FIG. 1A is a cross-sectional view illustrating a schematic configuration of a CVD apparatus which is an embodiment of a vacuum processing apparatus according to the present invention, and FIG. 1B is a portion indicated by a dashed line in FIG. It is an enlarged view of P.

As shown in FIGS. 1A and 1B, a CVD apparatus (vacuum processing apparatus) 1 of the present embodiment has a vacuum processing tank 2 connected to a vacuum pump (not shown). In the tank 2, for example, 2
It is configured to introduce different types of source gases A and B.

A susceptor 4 for supporting the film-forming target 3 is provided below the vacuum processing tank 2. The susceptor 4 includes a susceptor body 5 attached to the bottom surface of the vacuum processing tank 2 and a deposition prevention member 6 attached to the susceptor body 5. In the upper part of the susceptor body 5, a housing recess 50 having a shape capable of housing the electrostatic chuck 7 is provided.
Is provided.

FIG. 2A is an explanatory plan view showing a film-forming region and a non-film-forming region of a film-forming object used in the present embodiment, and FIG. FIG. 3 is an explanatory front view showing a film formation region and a non-film formation region.

In the case of the present invention, the film formation target 3 includes, for example, various things such as a silicon wafer, a glass substrate, and a metal substrate.

As shown in FIGS. 2A and 2B, in the present embodiment, a region 3a where a film is to be formed at the center of the surface of the film-forming target 3 (hereinafter, referred to as a "film-forming region"). It is assumed that the peripheral portion and the side surface of the film formation target 3 form a region 3b where no film is formed (hereinafter, referred to as a “non-film formation region”).

As shown exaggeratedly in FIG. 1B, the susceptor main body 5 of the present embodiment comprises a bottom surface 7a and a side surface 7b of the electrostatic chuck 7 housed in the housing recess 50 and a bottom surface 5a of the susceptor body 5. It is configured such that a predetermined gap is formed between the inner wall 5b and the inner wall surface 5b.

On the other hand, the attachment-preventing member 6 is formed in a ring shape having the same outer diameter as the upper end of the susceptor body 5.
An eave portion 6a having a reflection supply surface 60 parallel to the bottom surface 5a of the susceptor body 5 is formed to bulge at an edge on the center side of the ring.

As will be described later, the eaves portion 6a prevents the deposition material from adhering to the non-deposition region 3b on the surface of the deposition target 3 and also prevents the deposition material introduced into the vacuum processing tank 2. This is for guiding a wearing gas (hereinafter referred to as “deposition-preventing gas”) 9 to the non-film-forming region 3 b on the surface of the film-forming target 3.

A heater 8 for heating the film formation target 3 is provided inside the electrostatic chuck 7.
The heater 8 is connected to a power source (not shown) so that the heater 8 can be controlled to a predetermined temperature.

On the other hand, as shown in FIG. 1A, a deposition gas 9 for introducing a predetermined deposition gas 9 into the vacuum processing tank 2 outside the vacuum processing tank 2, for example, below the vacuum processing tank 2. An introduction means 10 is provided.

The deposition gas introducing means 10 is provided with a deposition gas 9
Is provided.
In the present embodiment, the deposition gas 9 generated by the deposition gas generating means 11 is evacuated through the deposition gas introduction pipe 12 and the deposition gas introduction hole 51 provided in the susceptor body 5. It is configured to be introduced into the processing tank 2.

FIG. 3 is a plan view showing a susceptor body according to the present embodiment. As shown in FIG. 3, in the present embodiment, a plurality of deposition gas introduction holes 51 are provided in the susceptor body 5. These deposition gas introduction holes 51
Are arranged at regular intervals on the periphery of the bottom surface 5a of the susceptor body 5.

As shown in FIGS. 1B and 2,
Each deposition gas introduction hole 51 is provided at a position radially outward from the inner edge 61 of the eave portion 6 a of the deposition prevention member 6. However, each deposition gas introduction hole 51 may be provided radially inward from the inner edge 61 of the eave portion 6 a of the deposition prevention member 6.

As shown in FIG. 1A, the deposition-preventing gas generating means 11 comprises a container body 13 capable of sealingly storing a raw material liquid 90 of an adsorption component (adsorption gas component) 9a contained in the deposition-inhibiting gas 9. And a bubble generating tube 14 for generating bubbles in the raw material liquid 90 stored in the container body 13.

The bubble generating tube 14 is connected to a gas source (not shown) filled with an inert gas 30 such as argon (Ar), nitrogen (N ₂ ), etc. The raw material liquid 90 in the container body 13 is immersed in the raw material liquid 90 so that a predetermined amount of the inert gas 30
To generate bubbles in the raw material liquid 90.

By the way, since film formation by CVD generally utilizes a chemical reaction on the surface of the film-forming target 3,
When the surface of the film formation target 3 is covered with an inert substance,
Reactive substances cannot be adsorbed and film formation is hindered. In this case, gas adsorption on the surface of the film formation target 3 is as follows.
The lower the temperature, and generally the higher the molecular weight of the gas, the greater the probability of adsorption and the longer the average time to desorption.

Therefore, the deposition-inhibiting gas 9 used in the present invention has a property that one end portion of the molecule excluding the inert gas contained in the gas has electric anisotropy. It is easily adsorbed on the surface of the film formation target 3 such as a silicon wafer, and the other end is inert and the source gas A,
It is preferable to use a material containing the adsorption component 9a that does not react with B.

The adsorbing component 9a of the deposition-inhibiting gas 9 has a moderately large molecular weight and its raw material from the viewpoint of ensuring film formation and easy handling in the film formation region 3a of the film formation target 3. It is preferable to use a liquid which is liquid at room temperature.

In the case of the present invention, the molecular weight of the adsorption component 9a of the deposition-preventing gas 9 is preferably 60 or more, more preferably 60 to 160.

When the molecular weight of the adsorption component 9a of the deposition gas 9 is 60
If it is smaller, a large amount of deposition gas 9 must be introduced in order to obtain the desired effect, and this causes the flow of the source gases A and B in the process space to be disturbed and the film to reach the original film formation region 3a. Is not formed.

On the other hand, a substance having an excessively large molecular weight is a solid at ordinary temperature, and therefore has a disadvantage that the structure of the means for introducing the substance into the vacuum processing tank 2 becomes complicated.

The substance having such a property is present in an organic substance having electrical anisotropy, and examples thereof include alcohols having a relatively large molecular weight.

In this case, examples of the alcohol which can be easily handled and have a sufficient effect include isopropyl alcohol (2-propanol: C ₃ H ₇ OH), butyl alcohol (C ₄ H ₉ OH), and triethylsilanol (Si (C
H ₃ ) ₃ OH), Si ₂ (CH ₃ ) ₅ OH and the like.

When performing the film forming process in the present embodiment, first, as shown in FIG. 1A, the film forming target 3 is set at a predetermined position, and the pressure in the vacuum processing tank 2 is reduced. (1
(× 10 ^-1 Pa to about 1000 Pa), and a predetermined amount of the inert gas 30 is introduced from the inert gas introduction pipe 14 into the raw material liquid 90 in the container body 13 of the deposition-preventing gas generating means 11.

As a result, bubbles of the inert gas 30 are generated in the raw material liquid 90 of the container body 13,
Is promoted, and the pressure in the container body 13 increases. When the introduction valve 15 of the deposition-inhibiting gas introduction pipe 12 is opened in this state, the above-described adsorbed component 9 is contained in the inert gas 30.
The deposition gas 9 containing a is sent out to the inside of the vacuum processing tank 2 through the deposition gas introduction pipe 12 and the deposition gas introduction hole 51 of the susceptor body 5.

Here, the amount of the adsorbing component 9a added to the inert gas 30 is 1/10000 of the amount of the inert gas 30.
The amount of the adsorbing component 9a is preferably 1/100, more preferably 1/1000 to 1/100 of the amount of the inert gas 30.
/ 100.

If the amount of the adsorbed component 9a with respect to the inert gas 30 is less than 1/1000 of the amount of the inert gas 30, the effect of preventing deposition of the film-forming material according to the present invention cannot be sufficiently obtained. If the amount of the adsorbed component 9a with respect to the active gas 30 is more than 1/100 of the amount of the inert gas 30, there is a disadvantage that the film-forming material does not easily adhere to the original film-forming region 3a and the film is hardly formed.

Further, in the case of the present invention, since the inert gas 30 does not play the role of preventing the raw material gases A and B from entering, the amount of the inert gas 30 introduced into the vacuum processing tank 2 is , Very little. Specifically, the amount of the inert gas 30 introduced into the vacuum processing tank 2 is preferably 1/200 to 1/5 of the amount of the raw material gases A and B, and more preferably the amount of the inert gas 30 Is 1 / the amount of the source gases A and B
It is 100 to 1/10.

Inert gas 30 introduced into vacuum processing tank 2
Is less than 1/200 of the amount of the source gases A and B,
There is a disadvantage that the effect of preventing deposition of the film-forming material cannot be sufficiently achieved.
/ 5, the raw material gas A in the vacuum processing tank 2
There is a disadvantage that the flow of B is disturbed and the film thickness of the film formation region 3a of the film formation target 3 becomes thin.

As shown in FIGS. 1 (a) and 1 (b), the deposition gas 9 sent to the vacuum processing tank 2 is
The susceptor body 5 is introduced into the recess 50 of the susceptor body 5 through the deposition gas introduction hole 51 of the susceptor body 5. The introduced deposition gas 9 collides with the reflection supply surface 60 of the eaves portion 6 a of the deposition member 6 and is deflected, and is deflected.
It flows toward b.

As a result, the adsorbed component 9 a of the deposition-inhibiting gas 9 is adsorbed on the surface of the non-film-forming region 3 b of the film-forming target 3, while the remaining component flows toward the inside of the vacuum processing tank 2. .

Next, two kinds of source gases A and B are introduced into the vacuum processing tank 2 through the source gas introduction pipes 20 and 21, and the film formation target 3 is heated by the heater 8 while being subjected to thermal CVD.
A predetermined film 50 is formed in the film formation region 3a of the film formation target 3 by the method.
To form In this case, the deposition-inhibiting gas 9 is continuously supplied to the non-film-forming region 3b of the film-forming target 3 until the film-forming process is completed.

As described above, in the present embodiment, when a film is formed on the film-forming target 3 in a vacuum, the deposition gas 9 is supplied to the non-film-forming region 3 b of the film-forming target 3. As a result, the surface is covered with the inert adsorption component 9a, so that the source gases A and B cannot be adsorbed in the non-film formation region 3b, and the film formation in the non-film formation region 3b is hindered. Can be

As described above, in the method of the present embodiment, since the gaseous adsorbed component 9a is adsorbed on the surface of the film formation target 3, the gas is caused to collide or react in the film formation space. Compared with the related art, it is possible to reliably prevent the deposition material from adhering to the non-deposition region 3b of the deposition target 3 with a considerably small amount of gas.

Moreover, according to the present embodiment, the film 50 formed on the surface of the film formation target 3 is hardly affected by the inert gas 30, and a high-quality film 50 can be formed.

On the other hand, the adsorbed component 9a once adsorbed on the surface of the non-film formation region 3b of the film formation target 3 is separated from the surface of the film formation target 3 after a predetermined time has elapsed. Since the deposition gas 9 is constantly supplied to the surface of the non-film-forming region 3b of the film-forming target 3, the deposition material is not supplied to the non-film-forming region 3b of the film-forming target 3 during film formation. Adhesion can be reliably prevented.

In the case of the present embodiment, the deposition gas 9
Since the raw material liquid 90 of a relatively organic compound such as isopropyl alcohol is used as a raw material of the adsorption component 9a, there is an advantage that handling is easy.

On the other hand, according to the CVD apparatus 1 of the present embodiment, the above-described method of the present invention can be efficiently performed, and the apparatus configuration can be simplified.

Furthermore, in the case of the present embodiment, since the deposition gas 9 is generated by generating bubbles in the raw material liquid 90 of the adsorption component 9a of the deposition gas 9, the deposition gas 9 is generated. Fine adjustment of the introduction amount of 9 can be easily performed, whereby film formation can be performed under optimal conditions.

In the above embodiment, the CV
Although the method D has been described as an example, the present invention is not limited to this, and can be applied to other film forming methods.

[0071]

As described above, according to the present invention, it is possible to reliably prevent the deposition material from adhering to the non-deposition region of the deposition target over the entire region of the deposition process with a small amount of gas. Can be. Further, according to the present invention, a film formed in a film formation region of a film formation target is hardly affected by an inert gas, and a high-quality film can be formed. Further, the vacuum processing apparatus of the present invention can efficiently perform a film forming process under optimum conditions while having a simple apparatus configuration.

[Brief description of the drawings]

FIG. 1A is a cross-sectional view illustrating a schematic configuration of a CVD apparatus as an embodiment of a vacuum processing apparatus according to the present invention. FIG. 1B is an enlarged view of a portion indicated by a dashed line in FIG.

FIG. 2A is a plan explanatory view showing a film formation region and a non-film formation region of a film formation target used in the present embodiment; FIG. Front explanatory view showing a film formation region

FIG. 3 is a plan view showing a susceptor body in the embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... CVD apparatus (vacuum processing apparatus) 2 ... Vacuum processing tank 3 ... Film formation object 3a ... Film formation area 3b ... Non-film formation area 4 ... Susceptor 5 ... Susceptor body 6 ... Member 6a eaves part 9 gas for prevention 9a adsorption component 10 gas-introducing means 11 gas-generating means 12 gas-introduction pipe 51 gas-introduction gas introduction hole
60 Reflection supply surface

[Procedure amendment]

[Submission date] April 12, 1999 (1999.4.1
2)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0057

[Correction method] Change

[Correction contents]

If the amount of the adsorbed component 9a with respect to the inert gas 30 is less than 1/10000 of the amount of the inert gas 30,
The effect of preventing the deposition of the film-forming material according to the present invention cannot be sufficiently obtained.
When the amount is more than 1/100 of the amount of the inert gas 30, there is an inconvenience that the film forming material hardly adheres to the original film forming region 3a and the film is hardly formed.

Claims (6)

[Claims] When a film is formed on a film-forming object in a vacuum, the surface of a non-film-forming region of the film-forming object is caused to adsorb an anti-wear gas containing an inert component. Characteristic method of preventing deposition of film forming material. 2. The method according to claim 1, wherein a gas for preventing deposition is continuously supplied to a non-film-forming region of the film-forming object during the film-forming. 3. The anti-wear gas has a molecular weight of 60 or more, and its raw material contains an adsorbed gas component generated from an organic compound which is liquid at room temperature.
The method for preventing adhesion of a film forming material according to any one of the above items. 4. When a film is formed on a surface of a film-forming object by a CVD method, a predetermined gas for preventing deposition is adsorbed on a surface of a non-film-forming region of the film-forming object. Item 1
4. The method for preventing a film-forming material according to any one of claims 3 to 3. 5. A vacuum processing tank capable of accommodating a film-forming object to be processed, a deposition-inhibiting gas introducing means for introducing a predetermined deposition-resistant gas into the vacuum processing tank, and a gas-introducing gas introduced by the gas introducing means. A deposition gas supply means for supplying deposition gas to the surface of the non-deposition region of the film formation target. 6. The deposition gas introducing means has deposition gas generating means for generating a deposition gas by generating bubbles in a raw material liquid of the deposition gas. The vacuum processing apparatus according to claim 5.