JP3072158B2 - Thin film formation method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for forming a thin film on a substrate by a CVD method.

[0002]

2. Description of the Related Art As a method of forming a thin film of this type, conventionally,
Photo-CVD to form a film by giving light energy to source gas
There is an ECR plasma CVD method in which a plasma is generated using electron cyclotron resonance caused by the interaction between a microwave and a magnetic field to form a film.

[0003]

According to the above-mentioned photo-CVD method, there is an advantage that a dense, high-quality thin film having a smooth surface can be formed, and the thin film has good adhesion to a substrate. On the other hand, according to the ECR plasma CVD method,
The speed of forming a thin film is faster than the photo-CVD method,
There is an advantage that a thin film can be formed quickly.

[0004] However, each of the thin film forming methods has the following advantages, as well as the following disadvantages, and it is an object of the present invention to eliminate these disadvantages.

[0005] First, the photo-CVD method has a drawback that it takes a long time to form a predetermined thin film and is inefficient because the speed of forming the thin film is low.
The method D has the disadvantage that the composition of the thin film is heterogeneous and easily contains impurities, so that the film quality is poor and the stoichiometric composition cannot be controlled.

Accordingly, an object of the present invention is to provide a thin film forming method capable of forming a thin film having a smooth surface and good adhesion in a short time while solving the above-mentioned disadvantages of the respective thin film forming methods and making use of the respective advantages. There.

[0007]

A feature of the present invention to achieve this object is to carry out a first step of forming a thin film only by a photo-CVD method for applying light energy for forming a thin film to a raw material gas, Thereafter, at least one of the photo-CVD method and the ECR plasma CVD method is used.
A second step of forming a thin film by the method is performed, and thereafter, a third step for finishing the film surface only by the photo CVD method is performed.

[0008]

According to the characteristic means of the present invention, the first step is:
A portion of the thin film that is in contact with the substrate is formed. A nucleus for forming the film is formed on the substrate, and the crystal is subsequently grown. In other words, it can be said that this is the step of forming the base of the film. That is, by performing the first step by the photo-CVD method, as described above, it is possible to form the basis of a film having a smooth surface, dense and good quality, and having good adhesion to the substrate. Can be.

Next, in the second step, the base of the film formed in the first step is further grown to form the core of the entire thin film. Therefore, if this step is performed quickly, it is effective in shortening the formation time of the entire thin film.
The process is a combination of light CVD and ECR plasma CVD,
Alternatively, by performing the ECR plasma CVD method, which can form a film more quickly, of both methods,
The core portion of the thin film can be formed quickly, and the entire time of forming the thin film can be reduced.

In the third step, the surface of the film formed in the first and second steps is finished. In this step, the performance of the entire thin film is improved by forming a high quality thin film surface. Can be. In the present invention, since the third step is performed by the photo-CVD method in the same manner as the first step, even if the surface of the film is somewhat uneven, it is filled, and the thin film having a smooth, dense and high quality film is formed. Can be finished.

As described above, the thin film formed by repeating the first, second, and third steps has good adhesion to the substrate, despite the fact that the core of the film is formed by the ECR plasma CVD method. A thin film having a smooth surface can be obtained.

[0012]

As described above, according to the method of forming a thin film of the present invention, a thin film having good adhesion to a substrate and having a smooth surface and good quality can be formed in a short time, and the production efficiency of the thin film is improved. , And improved economics.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a conceptual diagram showing an example of a CVD apparatus used to carry out the thin film forming method of the present invention.

Reference numeral 1 denotes a laser light source which is an example of a light source for performing the photo CVD method. (This light source may use an Hg lamp in some cases.) The laser light 2 from the laser light source 1 is irradiated through the light irradiation window 6 in parallel to the substrate 5 installed on the substrate holding table 4 in the film forming chamber 3. Is done. Further, a light checking window 7 for monitoring whether the film forming chamber 3 is irradiated with the laser beam 2 is provided at a position facing the light irradiation window 6 in the film forming chamber 3. A plasma generation chamber 8 is provided above the film formation chamber 3, and the plasma generated in the plasma generation chamber 8 is drawn into the film formation chamber 3 through a plasma extraction window 9. The upper part of the plasma generation chamber 8 is provided with a waveguide window 12 for guiding the microwave 11 from the rectangular waveguide 10.
A magnetic coil 16 for applying a magnetic field to generate a plasma in the plasma generation chamber is provided. Also, the plasma generation chamber 8
Is also provided with a source gas supply path 14 for supplying the source gas 13. On the other hand, a discharge path 15 for discharging the consumed source gas 13 to the source gas supply path 14.
Is attached to the film forming chamber 3.

In order to carry out the thin film forming method of the present invention by this apparatus, first, the substrate 5 is set on the substrate holding table 4 and the first gas is supplied into the film forming chamber 3 while the first gas is supplied. The process involves the implementation of a photo-CVD method. The first step is
This is performed by irradiating the laser beam 2 from the light irradiation window 6 along the substrate 5 substantially in parallel. In this first step, the base of the thin film is formed on the surface of the substrate 5. Next, as a second step, a film is grown by ECR plasma CVD, and the process moves to the formation of the core of the thin film. However, this second step needs to be performed at least by the ECR plasma CVD method, but may be performed by using the optical CVD method together. Next, the third
The process is performed only by the photo-CVD method to finish the surface of the thin film.

In the claims, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the configuration shown in the attached drawings.

[Brief description of the drawings]

FIG. 1 shows a CVD apparatus according to an embodiment.

[Explanation of symbols]

 5 Substrate 13 Source gas

──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Shigeru Morikawa 17 Nakadoji Minamicho, Shimogyo-ku, Kyoto, Kyoto Prefecture Inside the Kansai New Technology Research Institute (72) Inventor Takashi Kobayashi 17 Nakadoji Minamicho, Shimogyo-ku, Kyoto, Kyoto (56) References JP-A-2-200782 (JP, A) JP-A-2-163378 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C23C 16 / 00-16/56 H01L 21/205 H01L 21/31 INSPEC (DIALOG) JICST file (JOIS)

Claims (1)

(57) [Claims] 1. A thin film forming method for forming a thin film on a substrate (5) by a CVD method, wherein a first method of forming a thin film only by a photo CVD method for applying light energy for forming a thin film to a source gas (13). And then the light C
At least EC of VD method and ECR plasma CVD method
A thin film forming method in which a second step of forming a thin film by the R plasma CVD method is performed, and thereafter, a third step for film surface finishing is performed only by the optical CVD method.