JP3326595B2 - Thin film vapor phase growth method and vapor phase growth 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 method and apparatus for growing a thin film by supplying a source gas onto the substrate and growing the thin film on the substrate by utilizing a chemical reaction in the gas phase.

[0002]

2. Description of the Related Art A vapor phase growth method of a thin film allows a variety of materials such as oxides, nitrides, carbides, silicides, borides, etc., as well as simple metals, semiconductors and alloys, to be firmly applied to a substrate. In particular, in the manufacture of semiconductor devices,
This is one of the important thin film forming techniques frequently used for forming a nitride film, a polycrystalline Si film, an oxide film and the like.

Conventionally, as a vapor phase growth apparatus for growing a thin film by this vapor phase growth method, for example, an apparatus as shown in FIG. 3 has been used.

FIG. 3 is a sectional view showing a schematic structure of a conventional vapor phase growth apparatus.

[0005] In the drawings, reference numeral 1 'denotes a vapor phase growth apparatus main body. The vapor phase epitaxy apparatus main body 1 ′ includes an upper heating chamber 2 and a lower reaction chamber 3.

[0006] The heating chamber 2 and the reaction chamber 3 are connected by infrared rays (heat rays).
For example, a quartz panel 4 as an infrared transmitting member that transmits light. Reference numeral 5 denotes an O-ring for improving airtightness between the heating chamber 2 and the quartz panel 4.

In the upper part of the heating chamber 2,
An infrared heater 6 is provided. In addition, a vacuum exhaust device 9 is provided on the side surface of the heating chamber 2 via an exhaust pipe 7 and an opening / closing valve 8 as a pressure reducing means.

In the reaction chamber 3, a substrate holder (susceptor) 10 is provided below the quartz panel 4, and a substrate 11 is provided.
Are locked in a so-called face-down state.

On the side surface of the reaction chamber 3, a source gas supply pipe 12 for supplying the source gas into the reaction chamber 3 and an exhaust pipe 13 for exhausting the remaining source gas are provided.

The above is the schematic configuration of the conventional vapor phase growth apparatus 1 '. Next, a process of forming a thin film on the substrate 11 by the vapor phase growth apparatus 1' will be briefly described.

First, the open / close valve 8 of the exhaust pipe 7 is opened, and the inside of the heating chamber 2 is evacuated to a vacuum state by the vacuum exhaust device 9. Then, after the pressure is reduced, the infrared heater 6 is turned on to start heating the heating chamber 2.

The infrared rays emitted from the infrared heater 6 and transmitted through the quartz panel 4 heat the substrate holding table 10 and the substrate 11 in the reaction chamber 3 to a predetermined temperature, and then from the raw material gas supply pipe 12 to a predetermined temperature. Source gas is supplied into the reaction chamber 3.

By holding this state for a predetermined time, a predetermined thin film is grown on the substrate 11 in a vapor phase. Next, the infrared heater 6 of the heating chamber 2 is turned off,
The substrate 11 in the reaction chamber 3 is cooled to complete a series of thin film forming steps.

When the temperature of the heating chamber 2 is raised by the infrared heater 6, the temperature of the heating chamber 2 is reduced to a vacuum state. It was possible to reduce the power consumption of the infrared heater 6 when forming a thin film on the substrate 11.

[0015]

However, in the above-mentioned conventional vapor phase growth apparatus, there is a problem that it takes a long time to cool the substrate because the temperature is lowered slowly. For this reason, there is a problem that the production efficiency of the substrate on which the thin film is formed does not increase.

The present invention has been devised to solve the above-described problems. The present invention makes it possible to cool a substrate after forming a thin film in a short time, thereby improving the production efficiency of the substrate. It is a main object of the present invention to provide a method and an apparatus for growing a thin film which can be improved.

[0017]

To achieve the above object, the present invention provides a method for growing a thin film on a substrate by utilizing a chemical reaction in the gas phase, comprising the steps of: Performing the temperature raising process of the reaction system and the thin film growth process in the reaction system under the first pressure condition, and performing the cooling process of the reaction system under the second pressure condition higher than the first pressure condition. It is like that.

Further, the vapor phase growth apparatus according to the present invention comprises a reaction chamber for growing a thin film on a substrate by utilizing a chemical reaction of a vapor phase, and a heating chamber provided with a heating means for heating the substrate. A vapor-phase growth apparatus in which the reaction chamber and the heating chamber are separated by an infrared transmitting member, wherein the heating chamber has a decompression means for decompressing the chamber to generate a first pressure condition lower than atmospheric pressure. And a pressure increasing means for increasing a pressure in the room to generate a second pressure condition higher in pressure than the first pressure condition.

The pressure reducing means may be constituted by a vacuum exhaust device for evacuating the heating chamber, and the pressure increasing means may be constituted by a gas supply device for supplying an inert gas or the like into the heating chamber.

Further, under the first pressure condition, the heating means raises the temperature of the substrate in the reaction chamber through the infrared transmitting member to grow a thin film, and under the second pressure condition. Preferably, the heating means is cooled, and the temperature of the substrate in the reaction chamber is lowered via the infrared transmitting member.

According to the method and the apparatus for growing a thin film according to the present invention, the step of raising the temperature of the reaction system and the step of growing the thin film in the reaction system are performed under the first pressure condition lower than the atmospheric pressure. Since the thin film is grown by heating the heating means and raising the temperature of the substrate in the reaction chamber via the infrared transmitting member, the heating rate can be increased by the heat insulating effect, and the temperature during the growth of the thin film can be increased. At the time of holding, the power consumption of the heating means can be reduced.

Further, for example, an inert gas or the like is supplied from a gas supply device into the heating chamber as a pressure increasing means, and the reaction system is cooled under a second pressure condition higher than the first pressure condition. Alternatively, the cooling rate can be increased by cooling the heating means and lowering the temperature of the substrate in the reaction chamber through the infrared transmitting member, so that the production efficiency of the substrate on which the thin film is formed can be improved. .

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Here, an example of an embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a sectional view schematically showing a configuration example of a vapor phase growth apparatus according to this embodiment.

In the figure, reference numeral 1 indicates a vapor phase growth apparatus main body according to the present embodiment. The vapor phase growth apparatus main body 1 includes an upper heating chamber 2 and a lower reaction chamber 3.

The heating chamber 2 and the reaction chamber 3 are separated by, for example, a quartz panel 4 as an infrared transmitting member that transmits infrared rays, and the airtightness between the heating chamber 2 and the quartz panel 4 is enhanced. An O-ring 5 is interposed.

An infrared heater 6 is provided above the heating chamber 2 as a heating means, and a vacuum exhaust device 9 is provided on a side surface of the heating chamber 2 as a decompression means via an exhaust pipe 7 and an opening / closing valve 8. Have been.

Further, on the side of the heating chamber 2 opposite to the side where the above-described vacuum exhaust device 9 is provided, a gas supply device 1 as a pressure increasing means is provided via a gas supply pipe 14 and an opening / closing valve 15.
6 are provided.

In the reaction chamber 3, a substrate holding table (susceptor) 10 is provided below the quartz panel 4.
Are locked in a so-called face-down state.

The method of installing the substrate 11 is not limited to the face-down method described above, but may be a method of mounting the substrate 11 on a substrate holding table.

On the side surface of the reaction chamber 3, a source gas supply pipe 12 for feeding the source gas into the reaction chamber 3 and an exhaust pipe 13 for exhausting the remaining source gas are provided.

The above is an outline of a configuration example of the vapor phase growth apparatus according to the present embodiment. Next, a process of forming a thin film on the substrate 11 by the vapor phase growth apparatus 1 will be briefly described.

First, the open / close valve 8 of the exhaust pipe 7 is opened, and the inside of the heating chamber 2 is evacuated by the vacuum
After the pressure is reduced to a vacuum state (for example, 1 Torr or less), the opening and closing valve 8 is closed. Then, the infrared heater 6 is turned on under reduced pressure, and the heating of the heating chamber 2 is started.

The substrate holder 10 and the substrate 11 in the reaction chamber 3 are heated at a predetermined temperature (for example, 780) by infrared rays emitted from the infrared heater 6 and transmitted through the quartz panel 4.
° C), and then a predetermined source gas (for example, SiH ₄ , SiCl ₄ and H ₂ , SiH ₄ and O _2, etc.) is fed into the reaction chamber 3 from the source gas feed pipe 12. At this time, the pressure in the reaction chamber 3 is kept at, for example, 50 Torr.

In this state, a predetermined time (for example, 30
), A predetermined thin film is vapor-phase grown on the substrate 11.

After the formation of the thin film is completed, the infrared heater 6 of the heating chamber 2 is turned off, the opening / closing valve 15 of the gas supply pipe 14 is opened, and hydrogen or an inert gas is supplied from the gas supply device 16 (for example, 4 l / min). At a flow rate of
The pressure in the heating chamber 2 is increased to, for example, 760 Torr as a second pressure condition higher than the first pressure condition.

Then, under the second pressure condition, the substrate 11 in the reaction chamber 3 is cooled to, for example, 100.degree.

According to the vapor phase growth apparatus 1, when the temperature of the heating chamber 2 is raised by the infrared heater 6, the inside of the heating chamber 2 is set to a first pressure condition and a state lower than the atmospheric pressure (in this embodiment, a vacuum state). Since the pressure is reduced, the temperature rise time can be shortened by the effect of vacuum insulation, and the power consumption of the infrared heater 6 when forming a thin film on the substrate 11 can be reduced.

Moreover, the vapor phase growth apparatus 1 according to this embodiment
Since cooling is performed under the second pressure condition higher than the first pressure condition by supplying hydrogen or an inert gas, the infrared heater 6 and the quartz panel 4 are forcibly cooled. As a result, the temperature drop rate can be increased, and the production efficiency of the substrate on which the thin film is formed can be increased.

FIG. 2 is a graph showing the relationship between the temperature and the required time when conducting a thin film growth experiment on the vapor phase growth apparatus according to this embodiment and the conventional vapor phase growth apparatus.

In FIG. 2, (A) shows the case where the steps of temperature rise, thin film growth and cooling are performed in a vacuum state in the conventional vapor phase growth apparatus, and (B) shows the state in the conventional vapor phase growth apparatus.
(C) In the vapor phase growth apparatus according to the present embodiment, when the steps of temperature increase, thin film growth, and cooling are performed in a heating chamber with hydrogen flowing at 4 L / min, (C) shows the steps of temperature increase and thin film growth. Shows the case where the heating chamber is evacuated and the cooling step is carried out in a state where hydrogen flows into the heating chamber at 4 L / min.

In each of the experiments (A) to (C),
The growth conditions of the thin film were as follows: the temperature was 780 ° C., the growth time was 30 minutes, the reaction chamber was 50 Torr, hydrogen was flowed at 30 liter / min, and the cooling was performed to 100 ° C.

Comparing the results of these experiments, (C) according to the present embodiment shows that all the steps of raising the temperature, growing the thin film and cooling are performed by about 4 times.
Since it can be completed in 3 minutes, it can be shortened by about 27 minutes from the total of about 70 minutes of the conventional (A), and can be reduced by about 5 minutes as compared with the conventional (B). I understand.

Further, regarding the power consumption of the infrared heater,
According to the calculation of the inventor, (C) according to the present embodiment is:
All the steps can be performed with 55% of the power compared to the conventional (B), and it has been confirmed that the vapor phase growth apparatus and the vapor phase growth method according to the present embodiment have an excellent energy saving effect.

As described above, according to the vapor phase growth apparatus and the vapor phase growth method according to the present embodiment, it is possible to reduce the time required for all steps of temperature increase, thin film growth and cooling in forming a thin film on a substrate. In addition, power consumption required for heating can be suppressed, so that the efficiency of substrate manufacturing can be improved.

It should be noted that the above embodiment is merely an example of the present invention, and the present invention is of course not subject to any restrictions.

[0047]

The method of growing a thin film according to the present invention is a method of growing a thin film on a substrate by utilizing a chemical reaction in a gas phase. A process of raising the temperature of the reaction system and a process of growing a thin film in the reaction system under a pressure condition, and performing a cooling process of the reaction system under a second pressure condition higher than the first pressure condition. The vapor phase growth apparatus according to the present invention includes a reaction chamber for growing a thin film on a substrate by utilizing a chemical reaction in a gas phase, and a heating chamber provided with heating means for heating the substrate. A vapor-phase growth apparatus in which the reaction chamber and the heating chamber are separated by an infrared transmitting member, wherein the heating chamber has a decompression means for decompressing the chamber to generate a first pressure condition lower than atmospheric pressure. , The pressure in the room is increased to increase the pressure from the first pressure condition. And a pressure raising means for generating a second pressure condition, so that the temperature rise process of the reaction system and the thin film growth process in the reaction system are performed under the first pressure condition lower than the atmospheric pressure, or Since the heating means is heated and the thin film is grown by raising the temperature of the substrate in the reaction chamber via the infrared transmitting member, the temperature rising rate can be increased by the heat insulating effect. There is an effect that the power consumption of the heating means can be reduced.

Further, for example, an inert gas or the like is supplied into the heating chamber from a gas supply device as a pressure increasing means, and the reaction system is cooled under a second pressure condition higher than the first pressure condition. Alternatively, the cooling rate can be increased by cooling the heating means and lowering the temperature of the substrate in the reaction chamber through the infrared transmitting member, so that the production efficiency of the substrate on which the thin film is formed can be improved. This has the effect.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically illustrating a configuration example of a vapor phase growth apparatus according to an embodiment.

FIG. 2 is a graph showing a relationship between a temperature and a required time when a thin film growth experiment is performed on the vapor phase growth apparatus according to the embodiment and a conventional vapor phase growth apparatus.

FIG. 3 is a sectional view showing a schematic configuration of a conventional vapor phase growth apparatus.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 vapor deposition apparatus main body 2 heating chamber 3 reaction chamber 4 quartz panel (infrared transmitting member) 5 O-ring 6 infrared heater (heating means) 7 exhaust pipe 8 open / close valve 9 vacuum exhaust device (decompression means) 10 substrate holding table 11 Substrate 12 Source gas supply pipe 13 Exhaust hole 14 Gas supply pipe 15 Opening / closing valve 16 Gas supply device (step-up means)

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C23C 16/00-16/56 H01L 21/205

Claims (2)

(57) [Claims] 1. A reaction chamber for growing a thin film on a substrate by utilizing a chemical reaction in a gas phase, and a heating chamber provided with heating means for heating the substrate, wherein the reaction chamber and the heating chamber are A vapor deposition apparatus partitioned by an infrared transmitting member, wherein the heating chamber is provided with a pressure reducing means for reducing the pressure in the chamber to generate a first pressure condition lower than the atmospheric pressure, and increasing the pressure in the chamber. Pressurizing means for generating a second pressure condition higher in pressure than the first pressure condition; heating the heating means under the first pressure condition, and reacting the reaction chamber through the infrared transmitting member. Raising the temperature of the substrate to grow a thin film, cooling the heating means under the second pressure condition, and lowering the temperature of the substrate in the reaction chamber via the infrared transmitting member. Vapor growth equipment. 2. A heating chamber having a means for introducing a source gas and for growing a thin film on a substrate by utilizing a chemical reaction in a gas phase, and a heating chamber having a heating means. Is a method of growing a thin film on a substrate in the reaction chamber using a vapor deposition apparatus partitioned by an infrared transmitting member, wherein the step of disposing the substrate in the reaction chamber; Heating the heating chamber by reducing the pressure to a first pressure condition lower than the atmospheric pressure, heating the substrate in the reaction chamber via the infrared transmitting member, and introducing a raw material gas into the reaction chamber. A step of growing a thin film on the surface of the substrate;
A cooling step of raising the pressure to the pressure condition described above, cooling the heating means, and lowering the temperature of the substrate in the reaction chamber via the infrared transmitting member.