JPH11323559A - Cvd apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the interlayer boundaries of multilayered films and to efficiently deposit these films. SOLUTION: The respective raw materials from inflow pipes 21a, 22a, 51a of a manifold valve 18a are respectively supplied to any of reaction furnaces 11a, 11b, 11c. The materials from inflow pipes 21b, 22b, 51b of a manifold valve 18b are respectively supplied to any of the reaction furnaces 11a, 11b, 11c. Deposition is executed by the pyrolytic reaction of the materials of a group III and a group V in the one reaction furnace. The material mixture supplied thus far to, for example, the reaction furnace 11a and the material mixture supplied thus far to the reaction furnace 11b are selectively supplied by switching of the manifold valves 18a, 18b. The gaseous pressures of these reaction furnaces 11a, 11b are kept at the same value, by which the fluctuation in the pressures based on the switching is eliminated and the wasteful discarding of the materials in their supply pipelines 13a, 13b is obviated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a CV which can be applied particularly to a case of forming a multilayer film having a different composition ratio, such as an apparatus for forming a film by a chemical vapor deposition method (CVD method).
D apparatus.

[0002]

2. Description of the Related Art FIG. 2 shows a conventional apparatus of this kind. The reaction furnace 11 is provided with a heating unit 12 such as a heated carbon susceptor, and a raw material gas, that is, a reaction gas is supplied from the outside into the reaction furnace 11 through a supply pipe 13. Exhaust gas from the reaction furnace 11 is discharged from an exhaust pipe 14 to an exhaust gas treatment device 17 by a rotary pump 16 through an automatic pressure regulator 15. Although not particularly shown, the automatic pressure regulator 15 includes a controller, a control valve, and the like that detect a gas pressure in the reaction furnace 11 and automatically control the set pressure based on the detected gas pressure. Manifold valves 18a and 18b are provided so that a plurality of types of gases can be selected and mixed and supplied to the reaction furnace 11. Manifold valve 1
At 8a, a plurality of inflow pipes 21a, 22a are provided, a plurality of discharge pipes 23a, 24a are provided, and further, valves 25a, 26a, 27a, 28a are provided. The raw material gas flowing from the inflow pipe 21a is supplied to the discharge pipe 23a through the valve 25a, or supplied to the discharge pipe 24a through the valve 26a, and the gas supplied to the inflow pipe 22a is supplied to the discharge pipe 23a through the valve 27a. Or it is configured to be supplied to the exhaust pipe 24a through the valve 28a. Similarly, the gas supplied from the inlet pipe 21b of the manifold valve 18b is supplied to the exhaust pipe 23b or 24b by one of the valves 25b and 26b.
Further, the gas from the inflow pipe 22b is configured to be supplied to the exhaust pipe 23b or 24b by the valve 27b or 28b.

The exhaust pipe 23a of the manifold valve 18a
Is connected to the supply pipe 13 through the connection pipe 31a, the exhaust pipe 23b of the manifold valve 18b is connected to the supply pipe 13 through the connection pipe 31b, and the exhaust pipe 24a of the manifold valve 18a and the exhaust pipe 24b of the manifold valve 18b are Each is connected to the rotary pump 16 through a pipe 33 through connection pipes 32a and 32b. Carrier gas from a carrier gas source 35 such as hydrogen supply means passes through flow controllers 36a and 37a, respectively, and discharge pipes 23a and 24a of the manifold valve 18a.
To the discharge pipes 23b, 2 of the manifold valve 18b through the flow controllers 36b, 37b, respectively.
4b.

Further, the manifold valve 18a has
In the case where a group II source gas is supplied, for example,
Trimethylindium TMI is supplied from the material tank 38a to the inflow pipe 21a. This supply amount depends on the carrier gas source 35.
The carrier gas is supplied to the material tank 28a through the flow controller 39a, and the amount of TMI supplied to the inflow pipe 21a is adjusted by the flow rate adjusted by the flow controller 39a. Although not shown, triethyl gallium TEG is similarly supplied from another material tank to the inflow pipe 21a, and the supply amount is adjusted by a flow controller.

In the case where the V-group material is supplied from the manifold valve 18b, arsine AsH ₃ is supplied to the inflow pipe 21b.
The material is supplied from a material cylinder 38b by 9b, and the supply amount is adjusted by a flow controller 39b. Although not shown, phosphine PH ₃ is similarly supplied to the inflow pipe 22b, and the supply amount is adjusted by a flow rate controller.

A difference in gas pressure between the connection pipes 31a and 32a is detected by a differential pressure gauge 41a, and a flow rate controller 37a is controlled by a flow rate controller 42a to eliminate the differential pressure difference. Similarly, the difference between the gas pressures in the connection pipes 31b and 32b is detected by the differential pressure gauge 41b, and the flow controller 42b controls the flow controller 37b so as to eliminate the difference. For example, in the formation of a multilayer film, a group III TMI and a group V PH
₃ and is supplied to the reactor 11 respectively through the supply conduit 13, and the reaction they both gas mixture, with the reaction film is formed, the manifold valves 18a, by switching 18b, and TEG Group III The group V AsH ₃ is supplied to the supply line 13. This allows TEG
A mixed gas of AsH ₃ and AsH ₃ reacts, and a different film is formed on the film formed by the mixed reaction growth.

In order to minimize the fluctuation of the gas pressure when the supply of the raw material gas is switched, conventionally, as described above, for example, the TMI is supplied from the manifold valve 18a to the reactor 11 using a differential pressure system. In the state in which TEG is supplied to the rotary pump 16 through the vent pipe 33 from the discharge pipe, the TEG is supplied.
The output of the differential pressure gauge 41a, the flow controller 42a and the flow controller 32a are adjusted so that the gas pressure of the vent pipe 33 and the gas pressure of the vent pipe 33 are the same.
The pressure was adjusted so that there was no pressure difference between b and 32b. By switching the manifold valves 18a and 18b in this manner, films of layers of different components can be alternately formed to form a multilayer film. Generally, a heated carbon susceptor is used, and the temperature of the film forming substrate is about 7 ° C.
The reaction is performed by heating to about 50 ° C.

[0008]

As described above, conventionally, when the source gas is switched, the gas is not supplied to the reaction furnace so that the gas pressure supplied to the reaction furnace does not fluctuate.
Next, the gas to be supplied to the reaction furnace was directly discharged from the rotary pump 16 through the vent pipe at the same pressure as the supply pipe to the reaction furnace, and the raw material was wasted.

The gas supplied to the reaction furnace 11 has a high temperature inside the reaction furnace and the gas pressure has increased, while the gas supplied to the vent line 33 has a room temperature, Lower than the temperature of the gas pressure is also low,
That is, since the gas pressure in the supply line is increased and the gas pressure in the vent line 33 is decreased, the gas pressure is adjusted by a differential pressure gauge, a flow rate controller, and a flow rate regulator so that there is no difference between them.
As a material, the amount of gas supplied to the vent pipe 33 was larger than that supplied to the reaction furnace 11. Therefore, when the raw material is switched, the gas in the supply line expanded by the thermal decomposition is supplied to the vent line 33, and the temperature starts to flow at room temperature, and the pressure decreases.
On the other hand, the gas flowing in the vent line 33 is supplied to the reaction furnace 11 from the supply line 13 and reacts, and expands due to thermal decomposition to increase the pressure. In the vent line 33, the gas pressure increases on one side and the gas pressure decreases on the other side, and a large differential pressure is generated. For this reason, there is a problem that the smooth switching is not performed, the components of the film to be formed are not switched instantaneously, and the boundary of the multilayer film does not become a steep interface.

[0010]

According to the present invention, n reactors are provided, and each of them is supplied with a reactant by n supply pipes. On the other hand, a plurality of manifold valves are provided, and each of the manifold valves is provided with n inlet pipes and n outlet pipes, and the material flowing into one of the inlet pipes is supplied to any one of the n outlet pipes. The plurality of manifold valves are connected to n supply pipes through n connection pipes, that is, supplied to n reactors. In addition, a carrier gas is supplied to each discharge pipe from a carrier gas source, and the flow rate of the carrier gas is adjusted by a flow controller.

[0011]

FIG. 1 shows an embodiment of the present invention, and FIG.
The parts corresponding to are denoted by the same numbers, or the same numbers with suffixes of Roman characters. In this example, three reactors 11a, 11b, and 11c are provided as reaction furnaces. On the other hand, as a plurality of manifold valves, 18a,
18b are provided. In these manifold valves, the material from any one of the inlet pipes can be selectively supplied to any of the reactors. Reactors 11a, 11b,
Supply pipes 13a, 13b and 13c are connected to the inlet pipe 11c, respectively.
51a is provided in addition to 1a and 22a, and 52a is provided in addition to 23a and 24a for the discharge pipe so that material from any inflow pipe can be supplied to any one of the discharge pipes. Since the valves are provided, valves 25a, 26a and 27a, 28a for switching the material of the supply pipes 21a, 22a are provided in the discharge pipes 23a, 24a in the same manner as in the related art. 53
a and 54a are provided, and can be supplied to any of the discharge pipes 23a and 24a. Furthermore, the inflow pipes 21a, 22
Valves 55a, 57a, 58a are provided so that the material from a, 51a can be supplied to the discharge pipe 52a. The manifold valve 18b is similarly configured.

The discharge pipes 23a, 24a, 52a are connected to the supply pipes 13a, 1a through connection pipes 31a, 58a, 59a.
3b, 13c and discharge pipes 23b, 24b, 52
b is the supply pipe 1 through the connecting pipes 31b, 58b, 59b.
3a, 13b, and 13c. The carrier gas from the carrier gas source 35 is supplied to a flow controller 36a.
Are supplied to the discharge pipes 23a, 24a, 52a through the flow control device 36b.
2b. The exhaust gas in each of the reactors 11a, 11b, 11c is supplied to the rotary pump 16 through the automatic pressure regulators 15a, 15b, 15c, respectively.

With such a configuration, for example,
The material TMI is supplied to the reaction furnace 11a through the supply line 13a, and the material PH ₃ is supplied to the reaction furnace 11a through the supply line 13a, and a thermal decomposition reaction is performed to grow a film. I have. On the other hand, the group III TEG is supplied to the reaction furnace 11b through the supply line 13b, and the group V AsH ₃ is supplied to the reaction furnace 11b through the supply line 13b. Is being done.

In this state, by switching the material, the conventional III
The group TMI is switched from the reaction path 11a to the reactor 11b, and the group V PH ₃ is switched from the reactors 11a to 11b. Instead, the group III TEG and the group V AsH ₃ are supplied from the reactor 11b. 11a, the pressures of the reaction furnaces 11a and 11b become automatic pressure regulators 15a and 15b respectively.
b, the pressure is adjusted to the same value, and regardless of the material switching, the gas pressure in the reactors 11a and 11b does not fluctuate, the switching is performed smoothly, and the boundary of the formed film is clear. Becomes

The control of the film thickness and the mixing ratio of the material components are controlled by the flow controllers 36a and 36b and the flow controllers 39a and 39 for supplying the raw materials supplied from the respective inlet pipes.
9b and the inlet pipe 22 (not shown).
The supply amounts of the materials to be supplied to a, 22b, 51a, and 51b are also controlled by the flow rate adjusters. By changing the supply amounts of these materials, film formation with different mixing ratios is performed. , that is, in this example, the inflow pipe 22a, the 51a, both supplies TEG, and supplies the flow rate are different from each other, likewise, the inflow tube 22b, and supplies the PH ₃ together to 51b However, the supply flow rate has been changed.

In the above description, the supply to the reaction furnace 11c is not described. However, it is needless to say that a desired component material is supplied to the reaction furnace 11c and the reaction is performed. In any case, the gas pressures of the reactors 11a, 11b, and 11c are set to the same value by the automatic pressure regulators 15a, 15b, and 15c. Even if the gases are switched and supplied to each other, that is, the gas in the six inflow pipes in this example, there is no change in the gas pressure based on the switching, and the switching is performed quickly, that is, the composition of the target film is formed. Is quickly switched, and the boundary of the film becomes clear. Although three reactors are shown in the figure,
In general, more or more, such as five or six, are used, and accordingly, the number of input pipes and the number of discharge pipes of the manifold valve are respectively five or six.

[0017]

As described above, according to the present invention, a plurality of reactors are provided, and the materials sent to the pipelines are adjusted so that the temperature and pressure in each reactor are the same. Since the adjustment is performed and the materials supplied between the reaction furnaces are switched with each other, the pressure does not fluctuate in the switching of the multilayer film. In addition, all the raw materials can be used effectively without wasting through the conventional rotary pump to the waste gas treatment unit,
Multiple films can be grown at the same time.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing a conventional CVD apparatus.

Claims (1)

[Claims] 1. n having a heating section (n is an integer of 2 or more)
Reactors, n supply pipes for supplying reaction materials to the n reactors, n inlet pipes, n outlet pipes, and a plurality of switching valves,
A plurality of manifold valves that can switch and supply the material that has flowed into each one of the inflow pipes to any one of the n discharge pipes; and each of the n discharge pipes of the plurality of manifold valves,
A plurality of connection pipes respectively connected to the n corresponding supply pipes; a carrier gas source for supplying a carrier gas to each of the discharge pipes; and a flow controller for controlling a flow rate of the carrier gas supplied to the discharge pipes. A CVD apparatus comprising: