JPH0322520A - Vapor growth device - Google Patents

Abstract

PURPOSE:To improve the distribution of film thickness by uniformly evacuating in vertical direction by a method wherein an exhaust pipe, which evacuates in the downward direction, and another evacuation pipe, which evacuates in upward direction, are arranged in parallel with each other and they are used as a pair in evacuation. CONSTITUTION:Exhaust pipes 4A and 4B of the same shape are used, a pair or more of an exhaust pipe 4, which exhausts in downward direction, and another exhaust pipe 4B, which exhausts toward upward, are arranged. The gas pressure distribution can be made uniform by collectively connecting the exhaust valves 4A and 4B, and a uniform exhaust in vertical direction can be conducted.

Description

[Detailed description of the invention] [Summary] Vapor phase epitaxy (CVI) used for a shrimp layer or a certain film of various coatings
) Apparatus 6 can be used under a wide range of growth conditions, especially for epitaxial growth performed at or near normal pressure. In order to obtain an apparatus that does not impair the uniformity of film property distribution, a reaction chamber (1) and a plurality of susceptors (1) arranged in the reaction chamber and on which wafers to be grown are mounted are provided.
2) and a gas introduction pipe (
3), and an exhaust pipe (4) that is provided at a position opposite to the gas introduction pipe with the susceptor in between and has a plurality of openings in the axial direction and exhausts the reaction chamber, (1) the exhaust pipe The exhaust pipe (4A) exhausts air in a downward direction and at least one exhaust pipe (4B) adjacent thereto exhausts air in an upward direction, which are arranged in parallel.

(2) The exhaust pipe is divided into a plurality of chambers in the axial direction of the pipe so that exhaust can be discharged independently from each other.

[Industrial application field]

The present invention is directed to the use of gas-phase coatings (
(CVD) equipment.

The CVD apparatus of the present invention can be used to form a layer, a conductive layer, an insulating layer, etc. on a substrate in a wafer process for manufacturing semiconductor devices.

In recent years, CVD equipment (CVD equipment in a broad sense including epitaxial growth equipment) is desired to have large throughput, large diameter wafer processing, and uniformity of film property (film quality and film thickness) distribution.

Therefore, the equipment itself was made larger and the wafers to be processed were arranged densely within the equipment. Furthermore, there is a demand for an apparatus that can provide good uniformity.

[Conventional technology]

In conventional shrimp/CVO equipment, the wafer is rotated to make the film thickness distribution uniform. The reaction gas was supplied and exhausted as follows.

FIG. 4 is a schematic sectional view of a conventional shrimp/CVO device, and FIG. 5 is a plan view thereof.

In the figure, a large number of susceptors 2 are vertically arranged and held in a reaction chamber 1, and a reaction gas is introduced into the susceptor chamber through a gas introduction pipe 3 and exhausted through an exhaust pipe 4, controlling the gas flow rate and exhaust speed. Adjust to maintain a predetermined gas pressure in the reaction chamber.

The susceptor 2 has a structure that allows it to rotate around a rotating shaft 5 while maintaining an airtight seal.

The susceptor 2 is heated by induction from the outside of the reaction chamber 1 by an RF coil 7.

The gas introduction pipe 3 is. It is provided at a position facing the exhaust pipe 4 with the susceptor 2 in between.

However, in the conventional model, there is only one exhaust pipe. In addition, in such an exhaust pipe, the gas flow rate is determined by the pressure difference inside and outside the pipe, and the pressure distribution inside the pipe in the vertical direction is determined by the diameter of the pipe and the number, size, and arrangement of holes. So high. It becomes lower at the bottom. It was difficult to control the distribution of film properties in the vertical direction. Particularly when the pressure is at or near normal pressure, there is a drawback that the distribution of membrane properties is not uniform.

[Problem to be solved by the invention]

Therefore. A scintillary film can only be formed under limited growth conditions, and in some cases it is necessary to create a scab with a lower quality in order to improve the uniformity of the film thickness.

In other words, in conventional CVD equipment, in order to make the film thickness distribution uniform, the lengthening conditions (substrate temperature, pressure of the lengthening gas, flow rate, and shape of the internal jig) are changed to perform lengthening. , the optimal conditions were sought.

However, the substrate temperature and Icho gas pressure. Changing the same flow rate would change the membrane quality itself, causing problems.

for example. When forming a high-concentration buried layer, first a high-concentration diffusion region is formed on the substrate surface, and when a shrimp layer is deposited on top of this, it depends on the growth conditions. The difference occurs in autodoping based on the migration of impurities in the gas phase.

That is, when epitaxial growth is performed at a pressure of Icho gas of 760 Torr, the amount of impurities taken into the layer from the high concentration diffusion region becomes large, and an impurity-introduced layer is formed over the entire interface with the substrate. On the other hand, if it is carried out at 60 Torr, the amount of impurities taken in will be reduced, and as a result, a lower pressure length will eliminate the need to form an extra impurity-introduced layer.

Among the growth conditions, changing the gas pressure causes a difference in autodoping as shown in this example, changing the temperature causes a difference in autodoping and crystallinity, and too high a flow rate worsens the crystallinity. When the growth conditions change in this way, the film quality changes.

As mentioned above, the conventional method is to improve the film thickness distribution. There was a limit to achieving both the same without changing the film quality.

The object of the present invention is to obtain a device that does not impair the uniformity of film property distribution under a wide range of conditions.

[Means to solve the problem]

The solution to the above problem consists of a reaction chamber (1) and a plurality of susceptors (2) arranged in the reaction chamber and on which wafers to be grown are placed.
and a gas introduction pipe (3) for introducing the reaction gas into the reaction chamber.
and an exhaust pipe (4) which is provided at a position opposite to the gas introduction pipe while sandwiching the susceptor, has a plurality of openings in the axial direction, and exhausts the reaction chamber. A vapor phase growth apparatus comprising at least one set of an exhaust pipe (4A) that exhausts air in the direction and at least one adjacent exhaust pipe (4B) that exhausts air in an upward direction arranged in parallel, or This is accomplished using a vapor phase growth apparatus that is divided into multiple chambers and configured to be able to exhaust air independently from each chamber.

[Effect]

The present invention provides exhaust gas using one or more pairs of an exhaust pipe that exhausts air in a downward direction and an exhaust pipe that exhausts air in an adjacent upward direction that are arranged in parallel. The pipe is divided into a plurality of chambers in the axial direction of the pipe, and the pumping speed is adjusted independently for each chamber to equalize the gas pressure distribution in the pipe in the vertical direction.

As a result, it is possible to uniformly exhaust the air in the vertical direction, thereby improving the film thickness distribution.

〔Example〕

FIGS. 1(1) and 1(2) are a structural diagram of an exhaust pipe and an exhaust system diagram according to an embodiment of the first invention.

Since the structural diagram of the entire device is the same as that of the conventional example, only the structural diagram of the exhaust pipe will be shown in the following embodiment.

In Figure 1 (1). By exhausting the air using 1m or more pairs of exhaust pipes 4A that exhaust air in a downward direction and an exhaust pipe 4B that exhausts air in an adjacent upward direction that are arranged in parallel. The gas pressure distribution inside the pipe in the vertical direction is averaged, making it possible to exhaust air evenly in the vertical direction.

Here, the exhaust pipes 4A and 4B are of the same shape. Also, should the exhaust pipe 4B for exhausting the air upward be attached to the upper part of the reaction chamber 1 in Fig. 4? Or fold it back and attach it to the bottom.

In FIG. 1(2), the exhaust pipe 4A is connected to the pump Pu through the valve VA, and the exhaust pipe 4B is connected to the pump Pu through the valve VB.

In particular, when the exhaust pipe 4B is folded back and attached to the lower part, the valve vA. Adjust VE to connect exhaust pipe 4A and exhaust pipe 4.
Make the pumping speed of B the same.

FIGS. 2(1) and 2(2) are a structural diagram of an exhaust pipe and an exhaust system diagram according to an embodiment of the second invention.

In FIG. 2(1), the exhaust pipe 4C is divided into upper and lower halves by a partition wall P, so that exhaust can be exhausted independently from each other.

The royal room is exhausted through exhaust pipe A.

In FIG. 2(2), the upper chamber of the exhaust pipe 4C is connected to the pump Pu through the valve vA, and the lower chamber of the exhaust pipe 4C is connected to the pump Pu through the valve VE.

Valve VA, V. Adjust. By adjusting the exhaust volume from the upper and lower chambers, the film thickness distribution of the upper and lower wafers can be controlled.

In this example, the exhaust pipe 4C is divided into two, but it may be divided into a larger number of chambers.

FIGS. 3(1) and 3(2) are a structural diagram of an exhaust pipe and an exhaust system diagram according to another embodiment of the second invention.

In Figure 3 (1). The exhaust pipe 4D is divided into upper and lower halves by the partition P, and is configured to be able to exhaust air independently from each other, but the difference from Fig. 2 is that the exhaust pipe A in the upper chamber is led out from the partition P through the inside of the lower chamber. The lower chamber of the exhaust pipe 4D is a double pipe, and the inside and outside of the double pipe are independently exhausted.

The feature of this structure is that since the external shape of the exhaust pipe 4D is the same as the conventional one, it is easy to attach to the reaction chamber and occupies less space.

In Figure 3 (2). The upper chamber of the exhaust pipe 4D is connected to the pump Pu through the valve V, and the lower chamber of the exhaust pipe 4D is connected to the pump Pu through the valve VB.

The film thickness distribution between the upper and lower wafers can be controlled by adjusting the amount of exhaust air from the upper and lower chambers by adjusting the valves VA and VE.

Next, we will explain examples of precepts using these devices.

Growth conditions Wafer: 8 inch φ Si wafer Number of wafers processed: 10 Film material: Si epi layer Growth gas: SiJ6+H2 Growth gas pressure: 4.5 Torr Growth gas flow rate: SiJ6300 SCCM, Hz
75SI! ．． M Substrate temperature = 900°C Growth rate: 0.1 μm/separate growth conditions Wafer: 8 inch φ Si wafer Processing 6 Number of wafers: 10 Film material: Si shrimp layer Growth gas: Si2}16+82 Growth gas Pressure: 100 Torr Gas flow rate: Si2H6100 SCCMH2751M. Substrate temperature: 900° C. Growth rate: 20.2 μm/min In all of the above examples, a film thickness distribution within 1±5% was obtained.

[Effects of the Invention] As explained above, according to the present invention, it was possible to obtain a shrimp/CvD apparatus that does not impair the uniformity of film property distribution under a wide range of growth conditions.

It is particularly effective for shrimp growth performed under normal pressure or pressure close to it.

[Brief explanation of drawings]

Figure 1 (1). (2) is a structural diagram of an exhaust pipe and an exhaust system diagram according to an embodiment of the first invention, and FIGS. 2 (1) and (2) are a structural diagram and an exhaust system diagram of an exhaust pipe according to an embodiment of the second invention. System diagram, Figures 3 (1) and (2) are a structural diagram of an exhaust pipe and an exhaust system diagram according to another embodiment of the second invention, and Figure 4 is a schematic cross-sectional view of a shrimp/CVD apparatus according to a conventional example. 5 is a plan view thereof. In the figure, 11 and 12 (i) are reaction chamber 2, susceptor 3 is gas introduction pipe, 4.4A to 4D are exhaust pipes, 5 is rotating shaft (1) structural diagram (2!) - T non-gas system diagram 1st plane Figure 30 of the actual color of the sun and moon 1st implementation of the second invention Figure 3 of the Jie series of Yi Bao

Claims (2)

[Claims] (1) A reaction chamber (1), a plurality of susceptors (2) arranged in the reaction chamber and on which wafers to be grown are placed, a gas introduction pipe (3) for introducing a reaction gas into the reaction chamber, and the susceptor. An exhaust pipe (4) is provided at a position opposite to the gas introduction pipe, has a plurality of openings in the axial direction, and exhausts the reaction chamber; ) and at least one set of exhaust pipes (4B) adjacent to the exhaust pipes (4B) for discharging air in an upward direction are arranged in parallel. (2) A plurality of susceptors (2) arranged in the reaction chamber and on which wafers to be grown are placed; a gas introduction pipe (3) for introducing a reaction gas into the reaction chamber; It has exhaust pipes (4) which are provided at opposite positions and have a plurality of openings in the axial direction to exhaust the reaction chamber, and the exhaust pipe is divided into a plurality of chambers in the pipe axial direction, and each can be independently evacuated. A vapor phase growth apparatus characterized by being configured as follows.