JPH01256118A - Vapor phase reaction equipment - Google Patents

Abstract

PURPOSE:To uniformize the substrate temperature, and enable the uniform film formation without generating slip, by forming a retaining stand in the manner in which the thickness of a part to mount a substrate becomes thin toward the center. CONSTITUTION:A retaining stand 44 is so formed that the opposite surface to the mounting surface to mount a circular substrate S decreases its thickness in two steps, from peripheral part toward the central part. The substrate S is mounted on a retaining stand 44, and reaction gas is supplied to the substrate S. When the retaining stand 44 is cooled while the substrate S is irradiated with infrared rays and heated, the substrate temperature is uniformized, because the central part of the substrate mounting part is formed thin. Thereby, the uniform film formation and surface treatment on the substrate are enabled without generating slip.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a susceptor (substrate support stand) which is a part of a gas phase reaction apparatus used for silicon epitaxial growth in the manufacture of semiconductor substrates, for example.

[Conventional technology]

When manufacturing a semiconductor thin film by epitaxially growing a silicon thin film on a silicon substrate by a gas phase reaction, for example, it is necessary to heat the substrate to about 1050'c using a heater such as an infrared lamp. In order to form a thin film of uniform thickness and good quality on a substrate, it is necessary to heat the substrate placed on the support stand so that the temperature of the substrate is uniform. FIG. 4 is a schematic cross-sectional view of a conventional device equipped with such a heater. The boss portion 5a of the support base 5 on which the substrate S is placed symmetrically with respect to the center is attached via the bearing means 4, and the reaction gas is introduced into the reaction vessel 1 through the through hole formed in the center of the support base 5. The supply pipe 7 is loosely fitted to drive the motor 8 to rotate the support stand 5, and at the same time, infrared rays are projected onto the substrate S and the support stand 5 from an infrared lamp 11 provided above the reaction vessel 1.
The reactant gas is passed through the nozzle 6 from the center to the periphery of the reaction chamber 10 to cause a gas phase reaction on the substrate S and to perform surface treatments such as thin film formation and etching on the substrate S. . In addition, 3a, . . . are a plurality of exhaust ports opened at the outer edge of the base 3, and 12 is a reflecting mirror for effectively projecting infrared rays emitted from the infrared lamp 11 onto the substrate S, and the solid line Arrows indicate the flow of reactant gas.

[Problem to be solved by the invention]

However, in the conventional device, the substrate is held at 1000°.
When heated to about C, the temperature difference between the center and the periphery of a 6 inch φ substrate will be about 60°C.
For this reason, there have been problems in that slips occur on the substrate, and the growth rate is non-uniform, resulting in only semiconductor thin films with non-uniform film thickness distribution being obtained.

The present invention has been made in view of the above circumstances, and includes reducing the thickness of the central portion of the mounting portion of the support base on which the substrate is mounted, and
It is an object of the present invention to provide a gas phase reaction apparatus that can uniformize the substrate temperature by partially increasing the cooling efficiency of a cooling gas, thereby forming a uniform film on the substrate without slipping.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a gas phase system configured to supply a reactive gas to a substrate placed on a support stand, heat the substrate with infrared rays, and perform film formation or surface treatment on the substrate. In the reaction apparatus, the supporting table is characterized in that the thickness of the portion on which the substrate is to be placed is thinner toward the center.

[Function] In the gas phase reaction apparatus according to the present invention, when the substrate is placed on the support, a reaction gas is supplied to the substrate, and the support is cooled while heating the substrate by irradiating infrared rays, the substrate is placed on the support. Since the central part of the part is thin, the substrate temperature is evened out.
Uniform film formation 3 surface treatment is performed on the substrate without causing slippage.

〔Example〕

Embodiments of the present invention will be described below based on the drawings. FIG. 1 is a schematic cross-sectional view of a gas phase reaction apparatus according to the present invention (hereinafter referred to as "the apparatus of the present invention"). As shown in the figure, 4
Reference numeral 0 denotes a reaction vessel, and a support stand 44 has a substrate S placed symmetrically through a bearing means 43 in the center hole of a disk-shaped base 42 that forms the outer shell of the reaction vessel 40 together with a dome-shaped Pelger 41. The boss portion 44a of the support base 44 is rotatably fitted into the reaction vessel 4, and the reaction gas is introduced into the through hole formed in the center of the support base 44.
A supply pipe 45 equipped with a nozzle 46 at the tip is loosely fitted in order to introduce the reaction gas into the reaction chamber 50 , and the motor 47 is driven to rotate the support base 44 .
The structure is such that a gas phase reaction is carried out on the substrate S by flowing from the center toward the periphery, thereby forming a thin film on the substrate S and subjecting the substrate S to surface treatment such as etching. In addition, 42a.

... are a plurality of exhaust ports opened at the outer edge of the base 42, and 48 and 49 are an infrared lamp and a reflecting mirror for heating the substrate S, respectively. In the above configuration, there is no particular difference from the conventional device, but in the present invention, the support base 4
Reference numeral 4 has a thinner wall at the center of the substrate mounting portion, and a cooling gas passage for cooling the support base is formed on the surface opposite to the substrate mounting surface. FIG. 2 is a partially enlarged sectional view of the support base 44 of the apparatus shown in FIG.

As shown in the figure, the support base 44 is formed so that the surface opposite to the mounting surface of the portion on which the circular substrate S is mounted has a wall thickness that decreases in two stages from the outer edge to the center. . Note that the dimensions (unit: mm) in the drawings are merely one example of the present invention. The boss portion 44 of the support base 44 is arranged so that the cooling gas can flow from the center of the support base in the radial direction of the cooling gas flow space formed between the support base 44 and the base base 42.
An introduction hole 44b is provided through the support base 44, and a flow path 51 is formed on the surface of the support base 44 opposite to the substrate mounting surface to allow cooling gas to flow therethrough. . Using such a gas phase reaction apparatus according to the present invention, Si substrates S,
...When forming a Si thin film on the surface, infrared lamp 48
At the same time, the substrate S is heated by irradiation with infrared rays, and H2 gas for cooling is passed through the flow path 51 to cool the substrate S while reacting gas 5itl□C! ! , 2 to supply pipe 45
It is supplied to the substrate S. In this case, since the support base 44 is formed thinner toward the center, the substrate S is heated to a high temperature.
The cooling efficiency by the cooling gas is better at the center of the Si substrate S, so that the substrate temperature is made uniform, and a uniform Sia film is formed on the surface of the Si substrate S without causing slip, which is a crystal defect.

FIG. 3 shows that S is deposited on a Si substrate using the apparatus of the present invention as described above.
This is a graph (indicated by a solid line in the figure) showing the deposition rate distribution on the surface of a 6-inch φ substrate S when an i-thin film is formed.The horizontal axis represents the position on the substrate, and the m-axis represents the deposition rate. It is expressed by taking V. In addition, the graph indicated by the broken line in the figure shows the film-forming rate distribution when the conventional apparatus is used. As is clear from the figure, according to the gas phase reaction apparatus according to the present invention, a Si thin film having a more uniform thickness can be formed on a Si substrate than in the conventional apparatus.

〔Effect of the invention〕

As explained above, in the gas phase reaction apparatus according to the present invention, the thickness of the center of the part of the support base on which the substrate is placed is made thin to increase the cooling efficiency of the cooling gas, thereby making the substrate temperature uniform. As a result, the present invention has an equivalent effect of being able to uniformly perform a film-forming 1 surface treatment on a substrate without causing slippage.

[Brief explanation of the drawing]

Fig. 1 is a schematic sectional view of the device of the present invention, Fig. 2 is a partially enlarged sectional view of Fig. 1, Fig. 3 is a detailed explanatory view of the invention, and Fig. 4 is a schematic sectional view of the conventional device. It is. 40... Reaction container, 41... Pelger, 42...
・Base, 42a...Exhaust port, 43...Bearing means, 4
4... Support stand, 44a... Boss portion, 46... Nozzle, 45... Supply pipe, 47... Motor, 50...
reaction chamber, 48...infrared lamp, 49...reflector,
51...Flow path, S...Shop plate patent Applicant: Sumitomo Metal Industries, Ltd. Agent Patent attorney: Noboru Kono
Husband 1 Figure 2 Location on the board Figure 3

Claims (1)

[Claims] 1. A gas phase reaction configured to supply a reactive gas to a substrate placed on a support stand, heat the substrate with infrared rays, and perform film formation or surface treatment on the substrate. A gas phase reaction apparatus, wherein the support table is formed so that the thickness of the portion on which the substrate is to be placed is thinner toward the center.