JPH046840A - Vapor growth apparatus - Google Patents

Abstract

PURPOSE:To obtain an apparatus in which a raw-material gas flows uniformly in a laminar- flow state on a substrate and by which crystals formed on the substrate by a vapor growth operation can be formed in a uniform thickness or at a uniform composition by a method wherein rotor blades are installed on the side face of a substrate-mounting stage and gas discharge tubes are formed at the upper part of a substrate for vapor-growth and on the side face of a reaction container. CONSTITUTION:This apparatus is composed of the following: a substrate-mounting stage 2 which is installed inside a reaction container 1, on which a substrate 3 for vapor-growth use is mounted and which can be turned; a gas supply tube 4 which is installed on the sub strate 3 for vapor-growth use and which supplies a raw-material gas for vapor-growth use; and gas discharge tubes 14 which discharge the gas after a vapor growth reaction. At the apparatus, rotor blades 11 are installed on the side face of the substrate-mounting stage 2, and the gas discharge tubes 14 are installed at the upper part of the substrate 3 for vapor- growth use and on the side face of the reaction container 1. For example, a plurality of sheetlike rotor blades 11 are installed on the side face of a substrate-mounting stage 2 at a prescribed pitch, and the rotor blades can be moved at a prescribed angle to the horizontal direction of the substrate-mounting stage 2. Gas discharge tubes 14 are installed on the side face of a reaction container 1 and in positions which are higher than the substrate-mounting stage 2 and which are adjacent to the substrate-mounting stage 2 so as to be extended in the horizontal direction.

Description

[Detailed Description of the Invention] [Summary] Regarding a vapor phase growth apparatus, an object of the present invention is to provide an apparatus that enables crystals to be formed on a substrate by vapor phase growth to have a uniform thickness or a uniform composition. a rotatable substrate installation stand installed in the reaction vessel on which a substrate for vapor phase growth is placed; and a gas supply pipe installed on the substrate for vapor phase growth and supplying raw material gas for vapor phase growth. and a gas exhaust pipe for exhausting gas after a vapor phase growth reaction, wherein a rotary blade is provided on a side surface of the substrate mounting table, and a rotary blade is provided above the vapor phase growth substrate and in the reaction vessel. It consists of a gas exhaust pipe installed on the side.

[Industrial application field]

The present invention relates to a vapor phase growth apparatus, and particularly to an apparatus in which epitaxial crystals, semiconductor films, etc. formed by vapor phase growth are formed with a uniform thickness.

2. Description of the Related Art Conventionally, semiconductor crystals such as silicon or semiconductor films such as silicon nitride films have been formed by vapor phase growth methods such as CVD.

[Conventional technology]

Such a conventional vapor phase growth apparatus will be explained using FIG. 4.

As shown in FIG. 4, a rotatable substrate installation stand 2 made of carbon or the like is installed in a reaction vessel 1 made of quartz glass or the like, and on this substrate installation stand 2 is placed a substrate installation stand 2 that is made of carbon or the like. A substrate 3 for vapor phase growth such as gallium arsenide (GaAs) is mounted.

Further, on the substrate installation stand 2, a gas supply pipe 4 for raw material gases such as diethyl tellurium and dimethyl cadmium for vapor phase growth is installed, and a container installation stand 5 on which the reaction vessel 1 is installed.
is provided with a gas exhaust pipe 6 for exhausting gas after vapor phase growth, and this gas exhaust pipe 6 is connected to an exhaust pump (not shown).

Then, a raw material gas is introduced into the reaction vessel, and the pressure inside the reaction vessel is reduced by an exhaust pump connected to the gas exhaust pipe,
A high-frequency induction coil 7 provided around the reaction vessel is energized to heat the substrate mounting table 2 to vapor-phase grow a semiconductor crystal on a substrate for vapor-phase growth.

[Problem to be solved by the invention]

However, in the conventional apparatus described above, the raw material gas supplied from the gas supply pipe 4 into the reaction vessel 1 is directed toward the gas exhaust pipe 6 along the side surface of the substrate installation table 2 as shown by arrow A. The gas flow becomes swirling and turbulent, especially on the side surface of the substrate mounting table 2, and a uniform laminar gas flow is not formed over the substrate in the periphery of the substrate mounting table.

Therefore, the supply amount of raw material gas is different between directly below the gas supply pipe 4 and around the substrate mounting table, and the substrate placed on the substrate mounting table with a wide area has a uniform thickness and crystals with a uniform composition. There are problems that are not formed.

An object of the present invention is to eliminate the above-mentioned problems and provide a vapor phase growth apparatus in which source gas flows uniformly over a substrate in a laminar flow state.

[Means to solve the problem]

The vapor phase growth apparatus of the present invention that achieves the above object comprises: a rotatable substrate mounting table installed in a reaction vessel on which a substrate for vapor phase growth is mounted; In an apparatus consisting of a gas supply pipe for supplying raw material gas and a gas exhaust pipe for exhausting gas after a vapor phase growth reaction, a rotary blade is provided on a side surface of the substrate installation table, and a rotary blade is provided on a side surface of the substrate mounting table, and A gas exhaust pipe is provided at the top of the reaction vessel and at the side of the reaction vessel. Further, the rotary blade is movable at a predetermined angle with respect to the horizontal direction of the substrate installation table.

[For production]

The apparatus of the present invention, as shown in FIGS. 1 and 2, cuts the flow of the raw material gas with a rotary blade 11 provided on the side surface of the substrate installation table 2, thereby reducing the flow of the raw material gas as in the conventional apparatus. This is to prevent the flow from rapidly increasing in speed on the side surface of the substrate mounting table 2 and forming a vortex, resulting in a turbulent state.

In addition, by providing a gas exhaust pipe 14 extending laterally on the side of the reaction vessel l and near the top of the substrate installation stand 2, the flow of the raw material gas passes over the substrate surface in a laminar flow state, with a uniform concentration. Because the raw material gas is supplied onto the substrate, uniform thickness,
And crystals with uniform composition can be formed by vapor phase growth.

〔Example〕

FIG. 1 is a schematic diagram of a vapor phase growth apparatus of the present invention, and FIG. 2 is a plan view of a main part of the vapor phase growth apparatus.

As shown in FIGS. 1 and 2, the apparatus of the present invention differs from conventional apparatuses in that a large number of plate-shaped rotary blades 11 are provided on the side surface of the substrate installation table 2.

The rotary blades are made of carbon, which is the material used to form the substrate mounting table, and are provided in plural at a predetermined pitch.

To explain in more detail, as shown in FIG. 3, a recess 12 is provided in the side surface 2A of the board installation stand, and the rotary blade 11 is fixed to this recess 12 using screws 13, etc. It can be adjusted to form a predetermined angle θ with respect to the horizontal direction, and the flow of raw material gas is cut off at an appropriate angle.

Further, as shown in FIGS. 1 and 2, a gas exhaust pipe 14 is provided on the side of the reaction vessel 1, above the substrate installation table 2, and in a position close to the substrate installation table so as to extend horizontally. .

In such an apparatus of the present invention, hydrogen gas is introduced as a carrier gas into an evaporator (not shown) containing raw material liquids of diethyl tellurium, dimethyl cadmium, and mercury. The partial pressure of the hydrogen gas supporting diethyl tellurium is 2.4 Xl0-' atm, the partial pressure of the hydrogen gas supporting dimethyl cadmium is 5.0 Xl0-' atm, and the partial pressure of the hydrogen gas supporting mercury is 2.4 Xl0-' atm. Introduced into the reaction vessel 1 at a partial pressure of 6 Xl0-3 atmospheres. Then, the inside of the reaction vessel 1 is depressurized to 100 torr using an exhaust pump (not shown) connected to the gas exhaust pipe 14, and the high-frequency induction coil 7 provided around the reaction vessel is energized to set the substrate mounting table. While maintaining the temperature of step 2 at 390° C., crystals of Hg+-Cd and Te are grown in a vapor phase on a substrate 3 for vapor phase growth of CdTe.

In this way, the raw material gas supplied from the gas supply pipe 4 is delivered to the rotary blade 11 provided on the side surface of the substrate installation table 2,
The gas is supplied onto the substrate in a laminar flow state through the gas exhaust pipe 14 installed on the side of the reaction vessel 1 near the substrate installation table, and the gas flow is stabilized so that there is no change in thickness or composition. Hg+-eC grown in vapor phase on a semiconductor substrate
d. Te crystals can be stably formed.

In addition, by changing the rotational speed of the substrate mounting table and the angle θ of the rotary blade with respect to the horizontal direction of the substrate mounting table depending on the type of raw material gas introduced into the reaction vessel, the flow of gas on the substrate can be changed. CdTe crystal on the substrate by
It is also possible to grow a superlattice structure in which HgTe crystals are stacked in a multilayer structure.

Further, the rotor blade may be formed to have a tapered structure in the thickness direction.

Furthermore, although this embodiment describes the case where a semiconductor crystal is grown in a vapor phase on a semiconductor substrate, the present invention can also be applied to the case where a semiconductor film such as a silicon nitride film is formed on a semiconductor substrate by the CVD method. equipment is applicable.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, raw material gas is stably supplied onto the substrate for vapor phase growth in a laminar flow state, so that semiconductor crystals and semiconductor films whose composition and thickness do not fluctuate can be grown. It has the effect of being formed by vapor phase growth.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram showing an embodiment of the present invention, Fig. 2 is a plan view of the main part of this embodiment, Fig. 3 is a side view of the main part of this embodiment, and Fig. 4 is a conventional vapor phase growth method. FIG. 2 is a schematic diagram of the device. In the figure, 1 is a reaction container, 2 is a substrate installation stand, 3 is a substrate for vapor phase growth,
4 is a gas supply pipe, 5 is a container installation stand, 6.14 heather ¥ and example -
Zero wholesale plane country Figure 2 7f;
】Figure 3: Flowers, energy, gas, speed, speed, speed, speed, speed, speed, flow

Claims (2)

[Claims] (1) A substrate for vapor phase growth (
3) and a rotatable substrate installation stand (2); a gas supply pipe (4) installed on the vapor phase growth substrate (3) and supplying a source gas for vapor phase growth; In an apparatus comprising a gas exhaust pipe (14) for exhausting gas after a vapor phase growth reaction, a rotary blade (11) is provided on the side surface of the substrate installation stand (2), and a rotary blade (11) is provided on the side surface of the substrate installation table (2), and 3) A vapor phase growth apparatus characterized in that a gas exhaust pipe (14) is provided above the reaction vessel (1) and on the side surface of the reaction vessel (1). (2) The vapor phase growth apparatus according to claim (1), wherein the rotary blade (11) is movable at a predetermined angle with respect to the horizontal direction of the substrate installation table (2).