JPH0622980Y2 - Substrate support device in CVD device - Google Patents

Description

[Detailed description of the device] [Industrial applications]

The present invention relates to a supporting device that supports a substrate such as a semiconductor, and a CVD device that uses the supporting device to arrange substrates in parallel and form a predetermined thin film.

2. Description of the Related Art In recent years, the field of electronic components used in office automation equipment, televisions, computers, etc. has been rapidly developed and promoted. In the manufacturing process of semiconductor devices for these electronic parts, a CVD (vapor phase growth) apparatus is used to form a thin film of SiO ₂ , polysilicon or the like on a semiconductor substrate. The CVD apparatus includes a vertical CVD apparatus in which semiconductor substrates are vertically stacked and a horizontal CVD apparatus. These devices
It has the characteristic of batch processing that a large number of substrates can be processed at one time. A schematic vertical sectional view of a conventional vertical CVD apparatus is shown in FIG. 4, and a schematic sectional view of a horizontal CVD apparatus is shown in FIG. In FIG. 4, four supports 2 are inserted inside a bell jar type quartz tube 1 made of quartz. Notches are provided at equal intervals on each of the quartz rods that form the support 2, and a circular substrate 3 is directly fitted and placed in the notches. The apparatus shown in FIG. 5 is of a hot wall type, in which a plurality of substrates 3 are arranged in parallel by parallel grooves formed in the support 2.

[Problems to be solved by the device]

However, such a CVD apparatus has the following drawbacks.
That is, in order to form a uniform thin film on the substrate to be processed, it is necessary to widen the distance between the plurality of substrates fitted and mounted on the support. This is because the gas flow changes between the central part and the peripheral part of the substrate when the distance is narrowed, and therefore the thin film is not formed uniformly. On the other hand, in order to increase the productivity, it is necessary to increase the number of substrates to be processed at one time, but for that purpose, the distance between the substrates must be narrowed. Therefore, in the conventional apparatus in which a plurality of substrates are directly placed on the support, it is not possible to simultaneously satisfy the demand for thin film uniformity and the demand for productivity. In order to solve such a drawback, a method has been adopted in which a support plate larger than the substrate is provided on the support and the substrate is placed thereon. This method forms a thin film on the entire supporting plate on which the substrate is placed, and the part of the supporting plate that is not covered by the substrate (this part is around the supporting plate, so the thin film formed on it is uniform). The film has a poor uniformity) and is thrown away to use a substrate on which a thin film is formed almost uniformly. However, since the surface of the substrate is very flat and the supporting plate on which the substrate is placed is also very flat, they stick together. Therefore, it becomes very difficult to remove the substrate from the support plate after forming the thin film. Further, providing a large support plate between the supports requires, for example, a large diameter quartz tube 1 made of expensive quartz. This raises the manufacturing cost of the device and is inconvenient for the maintenance of the device. Therefore, an object of the present invention is to simultaneously process a plurality of substrates such as semiconductors in a CVD apparatus, improve the uniformity of a thin film formed on the substrates, and / or adjust the concentration of impurities introduced into the film appropriately. It is to provide a substrate supporting device for realizing the same. Another object of the present invention is to provide a substrate supporting device in which a substrate can be easily attached and detached.

[Means for Solving Problems]

In order to achieve the above-mentioned object, the supporting plate of the present invention is larger than the processing substrate, and has an opening at the center of the supporting plate that is almost the same size as the substrate and supports the substrate along the periphery of the opening. It has a plurality of clips for doing. Here, the substrate, the opening, and the support plate may be circular or polygonal. The processing substrate is not limited to the semiconductor, and may be a substrate such as a glass substrate or a ceramic substrate. The CVD apparatus of the present invention has a substrate supporting device in which the above supporting plates are arranged in parallel at a constant interval.

[Function of the device]

In the support plate of the present invention, the processing substrate is supported apart from the support so that it can be easily attached to and detached from the support plate. Further, in the CVD apparatus in which a plurality of support plates of the present invention are arranged in parallel at regular intervals, a large space is defined by the openings of the support plates facing the substrate. Therefore, the gas flows not only between the supporting plates but also between the supporting plates and the substrate supported by the supporting plates to the substrate, with the influence of the juxtaposition of the plurality of substrates being minimized.

【Example】

Next, an embodiment of the present invention will be described with reference to the drawings. First
The drawing shows a perspective view of a substrate support plate of the present invention supporting a semiconductor substrate, and FIG. 2 shows a sectional view thereof. In this embodiment, the processing substrate is a semiconductor, but is not limited to this and may be a substrate such as a glass substrate or a ceramic substrate. Support plate 2
Reference numeral 1 is for supporting the substrate 22 to be processed, and is circular in the drawing, but is not limited to this and may be polygonal. However, if the substrate to be processed is circular, the support plate is preferably circular. An opening 23 is provided in the center of the support plate 21. This opening is circular according to the circular substrate. Although it is smaller than the size of the substrate of the illustrated opening, it may be larger. If the opening is smaller than the size of the substrate, the gap between the support plate and the substrate supported by the support plate becomes narrow, and the gas flow flowing therethrough becomes small. Conversely, if you make the opening larger,
The gas flow is high. Thus, by adjusting the size of the opening, the gas flow can also be adjusted. However, if the opening is made too small, as will be described below, when a plurality of support plates are juxtaposed in the CVD apparatus, the space defined on the substrate becomes small and a uniform thin film is not formed. It will be difficult. On the other hand, if the opening is too large,
This is the same as when there is no support plate, and there is no point in providing a support plate. Around the opening 23, a plurality of clips 24 for supporting the substrate 22 away from the support plate 21 are provided.
The clip 24 prevents the substrate from coming into close contact with the support plate. The number of clips 24 should be determined from the viewpoints of reliable gripping of the substrate and ease of attachment / detachment, and is preferably three. With this clip, the substrate 22 is supported right above the opening 23 of the support plate 21 as shown in FIG. As mentioned above, when making the opening larger than the size of the substrate, the clip must be slanted or inverted L-shaped. FIG. 3A shows a plurality of support plates 21 in a bell jar type CVD apparatus in which a substrate 22 is supported by clips 24 and arranged at regular intervals in the vertical direction. Each support plate 21 is held by a support body 25. As is clear from this figure, the opening 23 of the supporting plate is located directly above the supported semiconductor substrate 22, and therefore the space between the upper substrate and the lower substrate is smaller than the space when there is no opening. A wide space will be formed. Therefore, the gas contributing to the deposition of the thin film can flow as shown by the arrow in FIG. 3A. That is, conventionally, the gas flows from the side directly to the substrate, but according to the present invention, the gas further flows between the support plate on the substrate and the substrate supported by the support plate. Therefore, in combination with the wider space on the substrate, it becomes possible to form a relatively uniform thin film on the substrate. Here, the gas flow is specified by the difference between the diameter of the substrate and the diameter of the opening, ie A, the distance between the substrate and the supporting plate, ie B, and the difference between the diameter of the supporting plate and the diameter of the opening, ie C. (Fig. 3A). Therefore, the uniformity of the thin film deposited on the substrate can be determined by changing A, B, and C described above according to the size of the substrate, the shape of the substrate, the desired thickness of the thin film, the processing time, and the like. Can be improved. It is clear that the concentration of impurities introduced into the thin film can also be optimized by using the support plate of the present invention. FIG. 3B is another embodiment of the present invention, in which a substrate 22 is clipped by a clip 24 in a hot wall type CVD apparatus.
A plurality of supporting plates 21 are supported by and are arranged in the lateral direction at regular intervals.

[Effect of device]

As described above, according to the present invention, by providing an opening in a supporting plate, an appropriate space can be defined on the substrate, and a gas can flow between the supporting plate and the substrate supported by the supporting plate. Therefore, the thin film formed on the substrate can be made uniform. Similarly, the concentration of impurities introduced into the thin film can be optimized. Further, since the substrate is supported by the clip provided on the support plate, the substrate can be easily attached and detached.

[Brief description of drawings]

FIG. 1 is a perspective view of a support plate supporting a substrate according to the present invention. FIG. 2 is a sectional view of the support plate of FIG. FIG. 3A is a partial cross-sectional view of a plurality of support plates arranged in a bell jar type CVD apparatus at intervals in the vertical direction. FIG. 3B is a partial cross-sectional view of a plurality of support plates positioned laterally at intervals in a hot wall type CVD apparatus. FIG. 4 is a schematic sectional view of a bell jar type CVD apparatus that holds a plurality of substrates without using a supporting plate. FIG. 5 is a schematic cross-sectional view of a hot wall type CVD apparatus that holds a plurality of substrates because a supporting plate is not used.

[Explanation of main symbols]

 1 ... Quartz tube, 2 ... Support 3 ... Substrate, 21 ... Support plate 22 ... Substrate, 23 ... Opening 24 ... Clip, 25 ... Support

Claims (3)

[Scope of utility model registration request] 1. A support plate in which a plurality of substrates to be processed are arranged in parallel with each other at intervals, and an opening having a size substantially equal to that of the substrates is provided in the center, and the substrate is the support plate. And a plurality of substrate supporting clips for supporting on the opening along the circumference of the opening and held in parallel by holding means. 2. A method in which a plurality of substrates to be processed are arranged in parallel at intervals and a thin film is formed on these substrates by CVD.
In the VD device, an opening having a size substantially the same as that of the substrate is provided at the center, and the substrate is separated from the support plate, and a plurality of clips for supporting the substrate for supporting on the opening are provided in the opening. A CVD apparatus comprising: a plurality of support plates that are provided along the periphery and a holding unit that holds the plurality of support plates at regular intervals. 3. The CVD apparatus according to claim 2, wherein the property of the thin film on the substrate is the difference between the size of the opening and the size of the substrate, and the support plate immediately above the substrate. The CVD apparatus according to claim 1, wherein the CVD apparatus is adjusted by the distance to the distance and the difference between the size of the support plate and the size of the opening.