JPS6265995A - Vapor phase synthesizing device - Google Patents

Abstract

PURPOSE:To permit the continuation of a vapor phase reaction for a long period of time and the synthesis of a compd. having uniform thickness distribution by disposing a nozzle for supplying a gaseous raw material which is slow in diffusion of a vapor phase synthesizing device on the down stream side of a nozzle for supplying a gaseous raw material which is fast in diffusion. CONSTITUTION:The gaseous raw materials A, B are respectively supplied from the nozzles 2, 2' for supplying the raw materials to the vapor phase synthesizing device having a heater 1 and a discharge pipe 5 to induce the vapor phase reaction in the reaction section and to deposit and AB compd. on a substrate 3. The nozzle 2' for supplying the gaseous raw material B which is slow in diffusion is disposed on the down stream side of the nozzle 2 for supplying the gaseous raw material A which is fast in diffusion in the above-mentioned gaseous raw material supply section. The distance L between the outlets of the above-mentioned two nozzles 2, 2' is preferably set at 0.5<L/D<10 where the inside diameter of the nozzles is d. The flow of the gaseous raw materials in the reaction section is thereby maintained normal without disturbance and the vapor phase reaction is stably continued for a long period of time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a gas phase synthesis apparatus for producing a compound by a gas phase reaction method with a thin layer or bulk crystal of a compound.

[Conventional technology]

A conventional gas phase synthesis apparatus for producing an AB compound from raw material gases A and B includes a heater 1, raw material supply nozzles 2, 2, a substrate 3, and an exhaust pipe 5, as shown in FIG.

Raw material gases A and B are supplied to raw material supply nozzles 2 and 2', respectively.
The ABB compound 4 is supplied to the reaction section and reacts, and the ABB compound 4 is deposited on the substrate 3.
is deposited.

[Disadvantages of the above conventional device]

In such a gas phase synthesis apparatus, raw material gases A and Bt
- Since the raw material gases A and B are mutually diffused at the outlet of the raw material supply nozzles 2, 2 to be supplied to the reaction section, the ABB compound 4 is deposited and deposited. At this time, a larger amount of AB is supplied to the raw material gas supply nozzle which has slower diffusion among raw material gases A and B.
The B compound will adhere and accumulate. For example, if the diffusion of B raw material gas is slower than that of A and B raw material gases, in the conventional device, a large amount of ABB compound 4 is deposited on the B raw gas supply nozzle as shown in Fig. 4. do. However, in this case, since the concentration of the A raw material gas is higher at the edge of the B raw gas supply nozzle closer to the A raw material gas supply nozzle, the deposition rate of the ABB compound 4 is faster, so it adheres to the B raw gas supply nozzle. The deposited ABB compound 4 grows curved in the direction away from the A raw material supply nozzle.

As a result, in the conventional gas phase synthesis apparatus, the flow of the raw material gas is disturbed, making it impossible to continue the normal reaction, and thus having the drawback that the reaction cannot be continued for a long time.

Furthermore, since the blowing direction of the raw material gas changes, it has the disadvantage that the thickness distribution of the ABS compound deposited on the substrate becomes non-uniform.

[Object of the present invention]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a vapor phase synthesis apparatus that eliminates all of the above-mentioned drawbacks of conventional apparatuses.

That is, the object of the present invention is to create a gas phase in which the flow of raw material gas in the reaction section is not disturbed and is maintained normally, gas phase reactions can be continued for a long time, and the thickness distribution of the compound to be synthesized is uniform. To provide synthesis equipment.

[Structure of the present invention] The present invention provides a first aspect of the invention as a means for achieving the above object.
As shown in the figure, the nozzle for supplying raw materials with slow diffusion is located longer downstream than the nozzle for supplying raw materials with faster diffusion. That is, in the raw material gas supply section of a vapor phase synthesis apparatus, the present invention arranges a fast-diffusing raw material supply nozzle on the upstream side and a slow-diffusing raw material supply nozzle on the downstream side, so that the fast-diffusing raw material gas is disposed in a slow-diffusing raw material gas supply nozzle. This is a gas phase synthesis apparatus characterized by being arranged so as not to adversely affect the supply of raw material gas.

The vapor phase synthesis apparatus to which the present invention is applied is applicable to compound semiconductors such as ZIS, ZlSe, CdTe, and GaAs.
, GaP, IMP, etc.) ABS compound thin layer or bulk crystal such as carbide, nitride, oxide, boride, etc. is manufactured by a gas phase reaction method. In particular, the present invention is effective for CVD apparatuses that require a high input concentration of raw material gas and a long synthesis time, such as a CVD apparatus that synthesizes ZnS Th using Zn vapor and H2S gas as all raw materials.

The present invention will be explained below based on the present invention and FIG. FIG. 2 is an enlarged sectional view of a raw material gas supply nozzle section according to an embodiment of the present invention. In FIG. 2, 2 is a fast-diffusing raw material gas supply nozzle, and 2' is a slow-diffusing raw material gas supply nozzle. If the relative distance between the raw material gas supply nozzles (distance between nozzle outlets) is '5L, and the inner diameter of each nozzle is d, then L/D
0.5 < L/D < 10 It is most appropriate to select the desired mechanism to be between 8 and 8.

[Experiment example]

All syntheses of ZoS compounds were carried out using the apparatus of the present invention and conventional apparatus. As a raw material gas, 2. A mixed gas of steam and carrier gas (Ar) and H2S gas were used.

The diffusion coefficient of each raw material gas is DI (8>DZn). Also, the conventional equipment used in this experimental example has two raw material supply pipes, one for H2S gas and one for Z and steam. The device of the present invention was made longer than the Zn vapor nozzle'!rH2s gas supply nozzle and arranged so that L/D=5.

In conventional equipment, as the synthesis reaction continues, ZnS is added to the Zn vapor supply nozzle, which is a raw material gas supply nozzle that diffuses more slowly.
The compound adheres and accumulates, and its growth rate is faster on the side closer to the H2S supply nozzle because the H2S gas concentration is higher on the edge closer to the H2S supply nozzle. As shown in the figure, the ZnS deposited on the Zn vapor supply nozzle bends and stretches in the direction away from the H2S supply nozzle. Disturbances occurred in the gas flow, making it impossible to continue normal gas phase reactions. Furthermore, the 7':ZnS crystal synthesized on the substrate had a nonuniform thickness distribution because the direction of the Zn vapor outlet changed.

On the other hand, in the device of the present invention, the Z vapor nozzle is equipped with Z.

Although S was adhered and deposited, it grew without bending, so there was no disturbance in the flow of the raw material gas, and the synthesis reaction could be continued for over 300 hours. -! : North Z on the board because the blowing direction of raw material gas did not change. The thickness of the S compound became uniform.

[Effects of the present invention]

As described in detail above, in the present invention, the supply nozzle for the slow-diffusing raw material gas is longer than the supply nozzle for the fast-diffusing raw material gas. Since the concentration of the raw material gas becomes almost uniform, the compound adheres to and grows on the raw material gas supply nozzle on the slow-diffusion side, but the growth rate is the same on either side of the nozzle, so there is no bending. Grow straight and straight. Because of this lick, even if a compound adheres to the nozzle part, the shape and direction of the outlet do not change, so the flow of raw material gas in the reaction part is not disturbed and is maintained normally, allowing the gas phase reaction to continue for a long time. This produces a moisturizing effect. Further, since there is no change in the blowing direction of the raw material gas, the thickness distribution of the compound to be synthesized becomes uniform.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a vapor phase synthesis apparatus of the present invention, and FIG. 2 is an enlarged sectional view of a raw material gas supply nozzle portion of the same apparatus. FIG. 3 is a sectional view of a conventional vapor phase synthesis apparatus, and FIG. 4 is an enlarged sectional view of a raw material gas supply nozzle portion of the same apparatus. 1... Heater 2... Fast-diffusing raw material supply nozzle 2'...
・・・・・・Slow diffusion raw material supply nozzle 3・・・・・・
...Substrate 1...AB compound 5...Exhaust pipe

Claims (1)

[Scope of Claims] (1) In the raw material gas supply section of the vapor phase synthesis apparatus, a raw material gas supply nozzle that diffuses slowly is arranged downstream of a raw material gas supply nozzle that diffuses quickly. Gas phase synthesis equipment. (2) The gas phase according to claim 1, wherein when the distance between the outlet of the raw material gas supply nozzle is expressed by L and the nozzle inner diameter is expressed by d, 0.5<L/d<10. Synthesizer.