JP2690613B2 - Method and apparatus for forming multilayer film - Google Patents

Description

TECHNICAL FIELD The present invention relates to a multilayer film forming method for continuously forming a multilayer film of a semiconductor device having a multilayer film structure in a plurality of film forming chambers, and an apparatus therefor. In particular, the present invention relates to a multilayer film forming method and an apparatus for forming a film using a plasma CVD method.

[Prior Art] The continuous film formation technology of a multilayer film by plasma CVD is an optical transmission type optical sensor using amorphous silicon (a-Si),
This is an important technology for manufacturing solar cells, TFTs, etc.

FIG. 5 is a diagram schematically showing a conventional multi-layer film forming apparatus. As shown in the figure, the apparatus is composed of independent processing chambers 41 to 45 which are shut off by a gate valve 46. There is.

In this apparatus, first, a glass substrate placed on a tray is introduced from the load chamber 41, and after evacuation, a multilayer film is sequentially formed in each of the film forming chambers 42, 43, and 44, and the unloading chamber 45 is opened to the atmosphere. Then, the semiconductor device having a multilayer film structure can be manufactured by taking out the semiconductor device again.

[Problems to be Solved by the Invention] However, in the conventional technique, when the processing time of a certain layer in the multilayer film is extremely long, the tact time is limited by this time, so that the entire processing time is shortened. It was difficult to do.

Also, in layers with large film thickness, layers with large internal stress of the film, layers with poor film adhesion, etc., the film adhered to the inner wall of the film formation, the electrode surface, etc. peels off as the film formation is repeated. However, there is a problem in that it adheres to the substrate as dust and reduces the yield of products.

Further, in order to reduce dust in the film forming chamber, it is necessary to frequently interrupt the film forming process to remove the film adhered to the inner wall of the film forming chamber and the electrodes, which is not efficient.

[Means and Actions for Solving the Problems] As a means for solving the above problems, the present invention continuously forms the multilayer film of a semiconductor device having a multilayer film structure in a plurality of film forming chambers. In the multi-layer film forming method, at least one layer of the multi-layer film is divided into two or more film forming chambers for continuous film formation, and the two or more film forming chambers are formed. Among the above-mentioned multi-layered films, the layers that are continuously divided and divided are layers excluding the layer having the shortest film formation time, and / or layers excluding the layer having the smallest internal stress, and / or the internal stress × A layer excluding a layer having the smallest film thickness, and / or a layer excluding a layer in which the least amount of dust is generated in the deposition chamber, wherein the multilayer film contains at least silicon nitride and amorphous silicon. To provide a method for forming a multilayer film characterized by

Furthermore, the present invention provides a multilayer film forming apparatus for continuously forming the multilayer film of a semiconductor device having a multilayer film structure in a plurality of film forming chambers, wherein at least one layer of the multilayer films is formed. The film forming chamber is configured by two or more continuous film forming chambers, and the two or more continuous film forming chambers are layers except the layer having the shortest film forming time in the multilayer film. , And / or a layer excluding a layer having the smallest internal stress, and / or a layer excluding a layer having an internal stress × a smallest film thickness, and / or a layer excluding a layer in which the least dust is generated in the deposition chamber, It is a film forming chamber, and the above-mentioned problem is solved by a multilayer film forming apparatus characterized in that the multilayer film contains at least silicon nitride and amorphous silicon.

According to the present invention, the tact time can be reduced and the throughput can be improved by providing two or more film forming chambers having a long processing time and dividing a single layer to form a film. .

Also, a film with a large film thickness, a film with a large internal stress of the film,
By providing two or more film-forming chambers for films that are easily adhered to the inner wall of the film-forming chamber, such as a film having poor adhesion, or which easily generate dust, and by dividing the film-forming process, It is possible to reduce the generation of dust due to the peeled film and improve the product yield.

[Examples] Hereinafter, examples of the present invention will be described with reference to the drawings.

(Example 1) Example 1 in the case of manufacturing an optical transmission sensor integrated with an amorphous silicon TFT will be described.

First, the typical film thickness of each layer of these semiconductor devices, the processing time, and the internal stress value of the film are shown in the following table.

In this example, the processing time of the i layer is as long as 3 hours, and the takt time is rate-controlled by this, which is 3 hours.

The value of [internal stress x film thickness] of the film is large in the insulating layer and i-layer. As the number of times of film formation increases, film peeling from the inner wall of the film formation chamber and electrodes increases, and this falls on the substrate. Due to
Product yield decreases. Therefore, at this point, the work of removing the film adhering to the film forming chamber is carried out, but conventionally the number of film formings during this period is about 20 to 40 times.

Therefore, in this embodiment, as shown in FIG. 1, two insulating layer deposition chambers (12 (a), 12 (b)) and two i layer deposition chambers are provided.
By setting the chambers (13 (a), 13 (b)), the film formation time for the i layer is 1.5 hours each, the tact time is 1.5 hours, and the number of film formations until film removal is about 2 times that of the conventional method. Double 40 ~
I was able to do it 80 times. As a result, it was possible to secure a larger production volume than the conventional type.

(Example 2) Example 2 in the case of manufacturing an amorphous silicon TFT
Will be described below.

The following table shows an example of the film thickness of each layer of these semiconductor devices, processing time, and internal stress of the film × film thickness value.

In this example, the value of [internal stress × film thickness] of the insulating layer is large, and film peeling in the insulating layer film forming chamber increases with an increase in the number of times of film formation, causing a reduction in product yield. Normally, at this point, work to remove the film adhering to the deposition chamber is performed.
Conventionally, the number of film formations during this period is about 30 times.

Therefore, in the present embodiment, as shown in FIG. 2, the film formation chamber for the insulating layer is set to two chambers 22 (a) and 22 (b) for film formation. As a result, the number of times of film formation until the film was removed was doubled to about 60 times. As a result, the apparatus down time due to the film removing work is relatively shorter than that of the conventional type, and a large amount of production can be secured.

(Example 3) Example 3 in the case of producing an amorphous silicon TFT integrated optical transmission sensor will be described below.

The following table shows an example of the film thickness of each layer of such a semiconductor device, the processing time, and the internal stress × film thickness processing time.

In this example, the processing time for the i layer is as long as 2 hours, and the takt time is 2 hours, which is conventionally limited by this.

In view of this, in this embodiment, as shown in FIG. 3, the i-layer film forming chamber was set to two chambers 33 (a) and 33 (b), and film formation was performed for 1 hour in each chamber. By doing so, the tact time was reduced to 1 hour, the overall processing time was shortened, and a large amount of production could be secured as compared with the conventional method and apparatus.

(Example 4) Example 4 of the present invention for improving film peeling of each layer at the time of manufacturing an optical transmission sensor integrated with an amorphous silicon TFT
Will be described below.

The table below shows an example of the defective rate due to film peeling of the 20th batch of P-CVD.

Also, FIG. 6 is a graph showing the relationship between the number of batches and the defect rate in the conventional method. As shown in FIG. 6, when 20 batches are exceeded, film peeling in the i-layer deposition chamber is performed. Defects due to this increase rapidly.

Therefore, in this embodiment, as shown in FIG. 4, the i-layer deposition chamber is set to three chambers of 53 (a) 53 (b) 53 (c), and the film thickness of each layer is equal (in this embodiment, 2000 Å each). ) Was used to form a film.

As a result, the defective rate due to film peeling in the film forming chamber of the i-th layer of the 20th batch was 3% as shown in the graph of FIG. The yield was improved.

As described above, according to this embodiment, it is possible to perform the production with a larger number of batches and a higher yield than the conventional one.

[Effects of the Invention] As described above, according to the present invention, in a semiconductor device having a multilayer film structure, a layer having a long film formation time and a layer having a large amount of dust in the film formation chamber can be formed in a plurality of film formation chambers. By dividing the film formation, the tact time can be shortened, peeling of the film adhered in the film formation chamber is reduced, dust adhering to the substrate is reduced, and product yield is improved. It is possible to increase the number of times of film formation until the cleaning of the jig such as, and to increase the input amount of the processing machine number.

[Brief description of the drawings]

1 to 4 are schematic views showing the apparatus and method of Examples 1 to 4 of the present invention, respectively. FIG. 5 is a schematic diagram showing a conventional apparatus and method. FIG. 6 is a diagram showing the relationship between the number of batches in conventional P-CVD and the defect rate due to film peeling. FIG. 7 is a diagram showing the relationship between the number of batches in P-CVD and the defect rate due to film peeling in Example 4 of the present invention. 11,21,31,41,51 …… Sample loading chamber 12 (a), 12 (b), 22 (a), 22 (b), 32,42,52 …… Insulating layer deposition chamber 13 (a ), 13 (b), 23,33 (a), 33 (b), 43,53
(A), 53 (b), 53 (c) …… i layer deposition chamber 14,24,34,44,54 …… n ⁺ layer deposition chamber 15,25,35,45,55 …… Unload chamber 16,26,36,46,56 …… Gate valve

Claims (6)

(57) [Claims] 1. A multilayer film forming method for continuously forming the multilayer film of a semiconductor device having a multilayer film structure in a plurality of film forming chambers, wherein at least one layer of the multilayer film is 2 A method for forming a multilayer film, characterized in that the film formation is performed continuously by dividing in one or more film forming chambers. 2. A layer formed by continuously dividing the film in two or more film forming chambers is a layer of the multilayer film except a layer having the shortest film forming time, and / or an internal stress A layer excluding the smallest layer, and / or a layer excluding the layer having the smallest internal stress × thickness, and / or a layer excluding the layer in which the least amount of dust is generated in the deposition chamber. Item 2. The method for forming a multilayer film according to Item 1. 3. The method for forming a multilayer film according to claim 1, wherein the multilayer film contains at least silicon nitride and amorphous silicon. 4. A multilayer film forming apparatus for continuously forming the multilayer film of a semiconductor device having a multilayer film structure in a plurality of film forming chambers, wherein at least one layer of the multilayer film is formed. The membrane chamber
A multi-layer film forming apparatus characterized by comprising two or more continuous chambers. 5. The two or more continuous film forming chambers are layers except the layer having the shortest film forming time in the multilayer film, and / or the layer excluding the layer having the smallest internal stress, and / or Or a layer excluding a layer having a minimum internal stress x a film thickness, and / or a layer excluding a layer in which the least amount of dust is generated in the film formation chamber. Multilayer film forming apparatus. 6. The multilayer film forming apparatus according to claim 4, wherein the multilayer film contains at least silicon nitride and amorphous silicon.