JPH0360027A - Vapor deposition device - Google Patents

Abstract

PURPOSE:To eliminate irregularities in film formation speed on a substrate and to realize uniform film thickness all over the surface not only by revolving the substrate on the axis of a device through revolution of a susceptor but also by rotating it on its own axis. CONSTITUTION:A plurality of susceptors 12 are placed on a small substrate 4 and a coverage body 2 is put thereon to prepare a reaction container. Silicon raw gas such as SiH2Cl2 gas diluted by hydrogen is introduced inside a reaction container from an air inlet 7, made to flow through a flow space on the substrate 4, and exhausted from an exhaust port 8. After setting the reaction container as above, the susceptor 3 is revolved while heating the substrate 4 by a heating means such as an ultraviolet ray lamp. If the device is provided with a small susceptor which rotates on its own axis, the substrate revolves around inside the reaction container while rotating on its own axis.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a vapor phase growth apparatus for growing a thin film of an insulator, a semiconductor, etc. on a semiconductor substrate or the like by passing a reactive gas over the substrate.

(Prior Art) Vapor phase growth equipment is widely used as a means for forming thin films on substrates. For example, in the field of semiconductor device manufacturing, a vapor phase growth apparatus is used to deposit 5iH2 (:
It! , SiH,,0□, etc., to form Sis S10! It is used in the growth process to form films such as.

Vapor phase growth is performed so that a large number of elements with the same specifications are formed on the same substrate. In order for the operating characteristics of each element to be uniform, it is necessary that the film formation rate be uniform over the entire length of the substrate. The main factors that determine this growth rate include the concentration and flow rate of the reaction gas in the reaction system on the substrate, and it is necessary to make these uniform in order to make the growth rate uniform.

FIG. 1 is a longitudinal sectional view showing an example of a conventional vapor phase growth apparatus. The device is basically a reaction vessel covered with a base 1 made of stainless steel or the like and a cover 2 made of quartz or the like.
A plurality of normally circular substrates 4 are arranged symmetrically on a support stand 3 therein.

The support stand 3 is configured to be able to rotate around the center of the container by a mechanism such as a motor 5 and gears 6. The reaction gas is supplied into the container from an air supply lower at the center of the container, and the substrate 4 A film is formed in contact with the surface of the container, and exits from a plurality of exhaust ports 8 provided around the container.

A difficulty in performing vapor phase growth using the conventional apparatus as described above is the non-uniformity of the lithium film rate.

FIG. 2 shows the relationship between the distance (r) of the group Fi2 from the center of the apparatus and the film formation rate (G). In the conventional device shown in Figure 1, the reaction gas is supplied from the center of the device, so the flow rate increases as it gets closer to the center, and the concentration of the active ingredient in the gas also increases as it gets closer to the center. . Therefore, as shown in FIG. 2(a), the film formation rate is high near the center of the reaction vessel and decreases toward the periphery. Such a difference in film formation rate naturally causes non-uniformity in the thickness of the vapor-phase grown film on the substrate, leading to non-uniformity in device characteristics as described above.

In order to eliminate the above-mentioned drawbacks of conventional devices, the present inventors developed a device as shown in FIG. 3 and filed a patent for it (Japanese Patent Application No. 19937-1983).

The device (hereinafter referred to as the device of the prior invention) is characterized in that a plurality of air supply lowers are located at the periphery of the device, and the exhaust port 8 is located at the center of the device. In this apparatus, the concentration of the reactant gas is high at the outer periphery, while the gas flow rate is high at the center, so changes in concentration and flow rate cancel each other out, and the film formation rate on the substrate surface becomes uniform.

As mentioned above, the device of the prior invention greatly contributes to uniformity of the film formation rate, but in the process of putting this device into practical use, it was found that there is still room for improvement. That is, compared to the vapor phase growth in the conventional apparatus shown in FIG. 1, the film formation rate in the vapor phase growth in the apparatus shown in FIG. 3 is warm and uniform. However, when examined in detail, there is still non-uniformity in the deposition rate on one substrate.

FIG. 2(b) shows the film formation rate by the apparatus of the prior invention shown in FIG. 3 in relation to the distance from the center of the reaction vessel, as in (a). As shown in the figure, the growth rate decreases near the center.

Such non-uniformity (difference between minimum and maximum deposition rate)
increases as the size of the substrate increases.

(Problems to be Solved by the Invention) The purpose of the present invention is to eliminate the non-uniformity of the film formation rate on the substrate that still remains even with the apparatus of the prior invention, and to uniformly coat the entire surface of the substrate even when using a large substrate. It is an object of the present invention to provide an apparatus capable of performing vapor phase growth to a film thickness of a certain thickness.

(Means for solving the problem) As mentioned above, as shown in Fig. 3, a plurality of reaction gas supply ports were placed at the periphery of the reaction vessel, and a gas exhaust port was placed at the center of the reaction vessel. If you use the device invented in the first application, the second
The large non-uniformity of the film-forming rate as shown in FIG. 3(a) is eliminated.The present inventors based on the apparatus of this prior invention and further improved it to achieve the above-mentioned object.

The gist of the present invention is the following vapor phase growth apparatus.

■ Vapor phase growth is performed on the surface of multiple substrates by placing multiple substrates on a support stand installed in a reaction vessel that has multiple reactive gas supply ports at the periphery and a gas exhaust port at the center. A vapor phase growth apparatus characterized by having a mechanism for rotating a support stand about the center of a reaction vessel and a mechanism for rotating a substrate on the support stand about the center.

■ Vapor phase growth is performed on the surface of multiple substrates by placing multiple substrates on a support stand installed in a reaction vessel that has multiple reactive gas supply ports at the periphery and a gas exhaust port at the center. 1. A vapor phase growth apparatus, characterized in that a reactive gas flow path is minimal at the center of the substrate.

■ Vapor phase growth is performed on the surface of multiple substrates by placing multiple substrates on a support stand installed in a reaction vessel that has multiple reactive gas supply ports at the periphery and a gas exhaust port at the center. An apparatus comprising: a mechanism for rotating a support base around the center of a reaction container; and a mechanism for rotating a substrate on the support base about the center of the support base; A vapor phase growth apparatus characterized by being extremely small.

(Function) Hereinafter, the structure and function of the device of the present invention will be explained in detail with reference to FIG. 4, which shows a device corresponding to an embodiment of the present invention.

FIG. 4 is a longitudinal cross-sectional view showing an example of the device of the present invention described in (2) above. Note that the same components as in FIGS. 1 and 3 are indicated by the same symbols.

This device is the same as the conventional device shown in Fig. 1 in that it has a shield 2 on top of a base 1 and a reaction chamber inside. The device is similar to the device of the prior invention shown in FIG. 3 in that a plurality of air lowers are located on the periphery of the base and the exhaust port 8 is located in the center. It is also the same as the devices shown in FIGS. 1 and 3 in that it rotates (revolutions) around the center of the device. That is, the base 1 is provided with a through hole in its center, through which the boss portion 10 of the support base 3 is inserted through the bearing 9, allowing the support base 3 to rotate.
The teeth of a gear 6 attached to the tip of the output shaft 11 of the motor 5 mesh with the teeth formed on the lower circumferential side of the boss 10, and when the motor 5 is driven to rotate, The support stand 3 is adapted to be rotated. An exhaust pipe serving as an exhaust port 8 is loosely inserted through the center of the boss portion 10 of the support base 3 so that its end face faces onto the support base 3. Although not shown, a device for heating the substrate 4,
For example, an infrared lamp is provided above the cover 2. .

The feature of the device of the present invention shown in FIG. 4 is that the base Vi4 not only rotates (revolutions) around the center of the device due to the rotation of the support base, but also rotates (rotates) around the center of the substrate itself. That is, on the support stand 3 there is a small support stand 12 on which - pieces of the substrates 4 are placed, and this small support stand 12 is as follows.
It is rotatably attached to the support base 3 by a shaft 13 at its center. Teeth 14 are cut on the outer peripheral surface of the small support base 12, and the teeth 14 mesh with the teeth 15 on the opposing surface of the support base 3, so that the small support base 12 rotates as the support base 3 rotates (revolutions). It has a rotating mechanism. Therefore, the substrate 4 placed on the small support table is rotated around its own center while largely revolving within the reaction chamber, comes into contact with the reaction gas, and a film is formed on its surface. Incidentally, when this apparatus is used for vapor phase growth of a silicon thin film, the support stand 4 and the small support stand 12 are preferably made of graphite coated with silicon carbide.

fc) in FIG. 2 shows the effect of the rotation of the substrate as described above. In other words, each part of the substrate moves between a position close to the center of the apparatus and a position far from the center of the apparatus due to the rotation, and the non-uniformity of the film deposition rate as shown in FIG. 2(b) almost disappears. .

In the apparatus of the present invention shown in FIG. 4, further measures are taken to minimize the flow path of the reaction gas at the center of the substrate. In this example, the cross-sectional shape of the covering body 2 is recessed at the center of the substrate 4 as shown in the figure, thereby narrowing the gas flow path at that portion. By such a means, the flow rate of the reaction gas increases at the center of the substrate, and the non-uniformity of the film forming rate as shown in FIG. 2(b) is eliminated.

As a means for adjusting this gas flow path, a control member 16 as shown in FIG. 5 and FIG. 6 (both are enlarged cross-sectional views of the right half of the device) can be used in addition to the configuration shown in FIG. 4. May be used.

The means for adjusting the reaction gas flow path as described above can be used in place of the aforementioned rotation of the substrate. That is, by either adjusting this gas flow path or rotating the substrate, the second
The effect of making the film formation rate uniform as shown in (C) of the figure is disappointing. However, by taking these two measures at the same time, the effect of equalizing the film formation rate will be even greater.For example, when the size of the substrate is large, the rotation of the substrate alone will not reach the level shown in Figure 2 (C). As shown, there may be a slight difference in the film formation speed between the center and the periphery. At this time, if a means is also taken to minimize the reactive gas flow path at the center of the substrate, the film forming rate can be made completely uniform as shown in FIG. 2(d).

Hereinafter, a vapor phase growth method for forming a silicon thin film on the surface of a silicon substrate using the apparatus of the present invention as shown in FIG. 4 will be explained.

First, a plurality of substrates 4 are placed on the small support stand 12, and the base 1
Prepare the reaction vessel by placing the cover 2 on top.

Next, as a silicon source gas, for example, 5iH2C1z gas diluted with hydrogen is introduced into the reaction vessel from the air supply lower, passed through the flow space above the group Fi4, and then discharged from the exhaust port 8. Here, after bringing the reaction vessel into such a state in which the amount of supply and exhaustion of the reaction gas are adjusted by adjusting means (not shown), the support stand 3 is heated while heating the substrate 4 with a heating means such as an infrared lamp. Rotate. At this time, if the apparatus is equipped with a small support base that rotates on its own axis as described above, the substrate 4 will revolve within the reaction container while rotating on its own axis. This alone has a great effect in making the film formation rate uniform on the substrate surface. Moreover, the same effect can be obtained by adopting means for adjusting the flow path of the reaction gas instead of the rotation. However, as described above, by adjusting the flow path of the reaction gas and rotating the substrate, the film formation rate can be made more uniform.

(Effects of the Invention) The apparatus of the present invention can be widely used in the technical field of vapor phase growth of thin films on substrates. Particularly, in fields such as manufacturing large-diameter epitaxial wafers for manufacturing charge-coupled devices (CCDs), where devices with uniform characteristics are required, the apparatus of the present invention, which allows uniform growth of a film, is of great utility.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view showing an example of a conventional vapor phase growth apparatus, FIG. The figure is a longitudinal cross-sectional view of a vapor phase growth apparatus previously proposed by the present applicant, FIG. 4 is a longitudinal cross-sectional view showing an example of the vapor phase growth apparatus of the present invention, and FIGS. FIG. 3 is a cross-sectional view showing an example of a reaction gas flow path control member in the invention device.

Claims (3)

[Claims] (1) Multiple substrates are placed on a support stand installed in a reaction vessel that has multiple reaction gas supply ports at the periphery and a gas exhaust port at the center, and vapor phase growth is performed on the substrate surfaces. What is claimed is: 1. A vapor phase growth apparatus comprising: a mechanism for rotating a support table about the center of a reaction vessel; and a mechanism for rotating a substrate on the support table about the center. (2) Multiple substrates are placed on a support stand installed in a reaction vessel that has multiple reactive gas supply ports at the periphery and a gas exhaust port at the center, and vapor phase growth is performed on the substrate surfaces. A vapor phase growth apparatus characterized in that a reactant gas flow path is minimal at the center of the substrate. (3) Multiple substrates are placed on a support stand provided in a reaction vessel that has multiple reactive gas supply ports at the periphery and a gas exhaust port at the center, and vapor phase growth is performed on the substrate surfaces. This apparatus includes a mechanism for rotating a support platform around the center of the reaction vessel, and a mechanism for rotating a substrate on the support platform around the center of the support platform, and a reaction gas flow path is connected to the substrate. A vapor phase growth apparatus characterized by being extremely small in the center.