JP3108939B2 - Vapor phase growth method and apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vapor phase growth method and apparatus using a solid or liquid raw material at room temperature and normal pressure.

[0002]

2. Description of the Related Art As is well known, in a vapor phase growth method, a raw material gas is supplied to a substrate heated to a desired temperature in a reaction tube and is thermally decomposed on the substrate. The product is deposited on the substrate to form a thin film.

In this case, when the raw material is solid at room temperature and normal pressure, the raw material is stored in a raw material container heated to a desired temperature, a high-temperature carrier gas is introduced into the container, and the carrier gas is introduced into the container. The thin film is formed by supplying the raw material vapor (raw material gas) onto the substrate in the reaction tube together with it.

At this time, the growth rate of the thin film on the substrate increases as the amount of the source gas supplied to the substrate increases.
In the vapor phase growth using the solid raw material, the raw material container or the carrier gas is heated to a high temperature to increase the vapor pressure of the raw material, thereby increasing the amount of the raw material gas supplied to the reaction tube. When the raw material is a liquid, the raw material vapor (raw gas) is supplied to the substrate in the same manner as described above by bubbling a carrier gas into the raw material.

[0005]

However, in the conventional method, the temperature of the raw material container or the carrier gas introduced into the container cannot be increased to a temperature higher than the decomposition temperature of the raw material. For this reason, the maximum amount of the source gas that can be supplied onto the substrate is limited by the decomposition temperature, and the growth rate of the thin film cannot be further increased.

When a thin film is manufactured on a substrate by using a plurality of raw materials, the plurality of raw materials are mixed in a state of a relatively high-temperature raw material gas and accompanied by a carrier gas. Sometimes. In this case, each raw material gas must be individually supplied into the reaction tube and mixed near the substrate, which has a disadvantage that the structure becomes complicated.

[0007]

Means for Solving the Problems The present inventors have made various studies to solve the above-mentioned inconveniences. As a result, instead of entraining the vapor of a solid or liquid raw material with a carrier gas, the raw material is converted into a liquid state in the reaction tube. It has been found that a thin film having the same quality as that of the related art can be obtained even when the atomized raw material obtained by the spraying is supplied onto the substrate, and the growth rate of the thin film can be much higher than that of the related art.

[0008] The present invention has been made based on the above-mentioned findings .
Atomized spray toward the substrate
Of hot inert gas from around the liquid material
The liquid material is heated and vaporized by spraying
And thermally decompose on the substrate .

Further, the vapor phase growth apparatus of the present invention has an internal base.
A reaction tube in which a plate is placed and a substrate for heating the substrate in the reaction tube.
Heating means, provided at one end of the reaction tube, facing the substrate;
Spray means for spraying the liquid raw material in mist and
It is installed, and a high temperature
And a gas supply ring for injecting inert gas.
Features .

[0010]

According to the present invention, the liquid raw material is sprayed into the reaction tube in the form of a mist, that is, a fine aerosol, and the sprayed mist of the liquid raw material is heated by a high-temperature inert gas to be gasified. By thermal decomposition, a reaction product is deposited on the substrate to form a thin film.

The liquid raw material to be sprayed into the reaction tube can be used as it is when the raw material itself is a liquid having low viscosity at room temperature and normal pressure, and when the raw material itself is solid at room temperature and normal pressure, Alternatively, in the case of a liquid having a high viscosity, it is desirable to dissolve it in an organic solvent before use. In particular, when a DPM (dipivaloylmethane) -based raw material is used as a raw material, when THF (tetrahydrofuran), trimethylamine, DPM, or the like is used as an organic solvent, polymerization is suppressed when the raw material is easily polymerized, and the raw material is decomposed. This is effective because it has the effect of suppressing decomposition when it is easy to perform, and does not adversely affect the formed thin film.

As described above, the liquid raw material is used in the method of the present invention, and the liquid raw material can be precisely adjusted to a desired concentration in advance.
Further, since the amount of spray can be precisely controlled, the quality of the thin film can be made equal to the conventional one.

In particular, in the method of the present invention, since the raw material is brought into a liquid state and introduced into the reaction tube, the concentration of the raw material can be significantly increased as compared with the conventional method in which the raw material gas is entrained in the carrier gas. Since the gas can be supplied onto the substrate, the growth rate of the thin film can be increased and the productivity can be improved.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described based on an embodiment shown in FIG.
This will be described in further detail .

First, in the figure, reference numeral 1 denotes a reaction tube constituting the present apparatus.
It is. The inside of the reaction tube 1 is for holding the substrate P.
A holding table 2 is provided, and a reaction at a position corresponding to the holding table 2 is performed.
An RF coil for heating the holding table 2 is provided on the outer circumference of the tube 1.
3 is provided. These holding table 2 and RF coil
3 is a heating means for the substrate P, and the substrate P is an RF coil 3
Desired temperature due to heat conduction accompanying induction heating of the holding table 2
Set to degree .

A spray nozzle is provided at one end of the reaction tube 1.
The other end is provided with an exhaust pipe 5,
The spray nozzle 4 stores the liquid raw material via the pipe 6
Communicates with the liquid phase of a container (not shown),
Is connected to a suitable pressurizing means via a pipe .

In the above configuration, the substrate P is
To a desired temperature and supply via a pipe 6.
The liquid material in the container to be supplied is sprayed onto the
Spray toward P.

A concentric double gas supply phosphorus is provided in the reaction tube 1.
Group 12 is installed. This gas supply ring 12
The atomized liquid raw material sprayed from the spray nozzle 4 is
To pass through the central hollow part of the ring 12
In addition, the entire inner peripheral surface 12a of the ring 12 is inactive at a high temperature.
The gas is injected toward the center of the reaction tube 1.
It is a thing .

According to the above configuration, from the spray nozzle 4
High temperature inert gas from around the atomized liquid raw material
Is sprayed toward the atomized liquid material, and the atomized liquid material
When passing through the central hollow portion of the ring 12,
Heated and vaporized by active gas, and inert at high temperature
A gaseous raw material wrapped in gas is attached to the inner surface of the reaction tube 1.
Is supplied to the substrate P without being reduced by
The area around the spray nozzle 4 can be kept clean.
It is. This also causes the liquid material to become a mist.
And supplied on the substrate P, gasified on the substrate P, and then
The thermal decomposition causes the reaction products to deposit on the substrate P to form a thin film.
It is .

[0020]

As described above, according to the present invention, the liquid source
Mist is supplied on the substrate in the form of a mist, and vapor phase growth is performed.
A much larger amount of source gas can be supplied onto the substrate
The productivity can be improved by increasing the growth rate of the film.

Further, a mist-like liquid source sprayed into the reaction tube is used.
The material is heated and vaporized by hot inert gas and
, Which is wrapped in high-temperature inert gas,
It is supplied to the substrate P without being reduced by adhering to the inner surface of the pipe.
Thus, the periphery of the spraying means can be kept clean.

[Brief description of the drawings]

FIG. 1 is a system diagram of a vapor phase growth apparatus showing one embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Reaction tube, 2 ... Holder, 3 ... RF coil, 4 ... Spray nozzle, 5 ... Exhaust pipe, 12 ... Gas supply ring, 12a
… Inner surface, P… Substrate

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-50-147879 (JP, A) JP-A-61-244025 (JP, A) JP-A-3-112894 (JP, A) JP-A-3-112894 8330 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 21/205 C23C 16/00

Claims (2)

(57) [Claims] 1. A liquid material is atomized toward a substrate in a reaction tube.
Around the sprayed mist liquid material
Inject high-temperature inert gas toward the atomized liquid raw material from
To heat and vaporize the liquid raw material and supply it to the substrate,
A vapor phase growth method characterized by thermal decomposition . 2. A reaction tube in which a substrate is placed, and said reaction tube
Heating means for heating the substrate in the tube, and one end of the reaction tube
And sprays the liquid material in the form of a mist toward the substrate.
Spraying means, installed in the reaction tube, and atomized from the inner peripheral surface
Gas supply for injecting high-temperature inert gas toward liquid raw materials
A vapor phase growth apparatus comprising a ring .