JPH02187018A - Chemical vapor phase deposition device - Google Patents

Abstract

PURPOSE:To form a uniform and satisfactory film on a wafer surface by providing a plurality of bottomed, box-shaped nozzles having an injection port for injecting reactive gas on a wafer surface in a gas tank freely to go in and out. CONSTITUTION:A wafer 4 is placed on a heating stage 3 of a reaction vessel 1. Nozzles 11-13 provided in a gas tank 5 are forced to go forward and backward to adjust a distance between each gas injection port 14-16 and the wafer 4. Hereby, the gas is injected on the water 4 surface to form a uniform and satisfactory film on the wafer 4 surface.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a chemical vapor deposition apparatus used in a semiconductor manufacturing process.

[Conventional technology]

Conventionally, this type of chemical vapor deposition apparatus has been constructed as shown in FIGS. 6A and 6B.This will be explained based on the figure. A reaction vessel has a gas introduction hole 2 for introducing an inert gas such as N2 gas, 3 is a heating stage provided in this reaction vessel 1 and holds a semiconductor wafer 4, and 5 is provided above this stage 3 and A gas tank is attached to the reaction vessel 1 and stores a reaction gas therein.A reference numeral 6 is provided in the gas tank 5 and is attached to the heating stage 3.
A gas ejection port 7 for ejecting a reaction gas onto the surface of the upper semiconductor wafer is provided in the reaction vessel 1 and connected to the heating stage 3.
An annular exhaust passage 81 extends around the gas tank 5 and is a gas supply port for supplying a reaction gas into the tank. Note that the arrow in the figure indicates the direction of gas flow.

In the chemical vapor deposition apparatus configured as described above, when the reactive gas in the gas tank 5 is ejected from the gas outlet 6 and reaches the surface of the semiconductor wafer 4, a part of the reactive gas is heated due to a thermochemical reaction. A produced film A is formed.

On the other hand, the remaining reaction gas (unreacted gas) passes through the exhaust passage 7 and is discharged to the outside. At this time, since the inert gas is introduced into the exhaust passage 7 from the gas inlet 2, it is possible to prevent the products from adhering to the wall surface inside the reaction vessel 1.

[Problem to be solved by the invention]

By the way, in this type of chemical vapor deposition apparatus, since the gas ejection surface of the gas tank 5 is configured to face the entire surface of the semiconductor wafer 4, the semiconductor wafer 4 is exposed from the gas inlet 2.
The reaction gas ejected towards the semiconductor wafer 4 has a flow in the radial direction of the wafer, and as shown in FIG. As the flow rate increased, the reaction at the periphery of the wafer surface was more active than at the center, as shown in FIG. 8(a). As a result, the thickness of the produced film A formed on the surface of the semiconductor wafer 4 is not uniform, resulting in a problem that good film formation cannot be achieved. in this case,
Depending on the distance between the gas tank 5 and the semiconductor wafer 4 or the amount of reaction gas ejected from the gas ejection port 6, the inert gas introduced into the reaction vessel 1 from the gas introduction port 2 may be affected. As shown in (b), the film thickness at the periphery of the wafer surface is thinner than the film thickness at the center.

The present invention has been made in view of the above circumstances, and is a chemical vaporizer that can uniformly set the thickness of the film formed on the surface of a semiconductor wafer, thereby achieving good film formation. A phase growth device is provided.

[Means to solve the problem]

A chemical vapor deposition apparatus according to the present invention includes a stage provided in a reaction container to hold a wafer, and a gas tank provided above the stage to store a reaction gas inside. A plurality of nozzles each having a gas outlet for ejecting a reactive gas onto the wafer surface are provided so as to be movable back and forth, and each of these nozzles is formed by a box with a bottom that operates independently.

Further, a chemical vapor deposition apparatus according to another aspect of the present invention includes a stage provided in a reaction container and holding a wafer, and a gas tank provided above the stage and storing a reaction gas therein, This gas tank is divided into a plurality of gas introduction chambers by a partition wall, and gas introduction ports for introducing reactive gases into each of these gas introduction chambers, and gas jetting ports for respectively spouting reactive gas onto the wafer surface on the stage are provided. It is installed in the gas tank.

[For production]

In the present invention, the distance between the gas outlet of the bottomed box and the semiconductor wafer on the stage can be changed during film formation.

In another aspect of the present invention, the amount of reaction gas ejected from each gas ejection port during film formation can be changed.

〔Example〕

EMBODIMENT OF THE INVENTION Hereinafter, the structure etc. of this invention will be explained in detail by the Example shown in the figure.

FIG. 1(a) and crest) are a cross-sectional view and a bottom view of essential parts of the chemical vapor deposition apparatus according to the present invention, and in the following figures, the same members as in FIGS. 6 to 8 are the same. Reference numerals are given and detailed explanations are omitted. In the figure, reference numerals 11-
Nozzles 13 each have a different outer diameter, and are provided in the gas tank 5 so as to be able to move forward and backward.
At the bottom facing the semiconductor wafer 4 on the heating stage 3, gas outlets 14 to 16 are provided, respectively, opening into the inside and outside of the box. These nozzles 11 to 13 each consist of a bottomed box that operates independently in the vertical direction, and among these, nozzle 11 is formed entirely in a cylindrical shape, and nozzle 12°1
3 is formed into a donut shape. And each nozzle 1
1 to 13 are positioned concentrically with each other.

In the chemical vapor deposition apparatus configured in this way, the distance between the gas ejection ports 14 to 16 of the nozzles 11 to 13 and the semiconductor wafer 4 on the heating stage 3 can be changed during film formation, so that the reaction gas Even if film formation conditions such as flow and temperature change, the thickness of the produced film A formed on the surface of the semiconductor wafer 4 can be set uniformly. That is,
Now, if the produced film A is formed thicker at the peripheral edge of the wafer surface than at the center, the nozzle 11 is moved forward toward the heating stage 3, and the distance between the gas outlet 14 and the semiconductor wafer 4 is reduced. This is because if the dimension is set to be smaller than the distance between the outlet 15 and the semiconductor wafer 4, the reaction gas can be blown more strongly to the center of the surface of the semiconductor wafer 4 than to the peripheral portion. Also, since the nozzle 13 is set back from the heating stage 3 compared to the nozzles 11.12, the distance between the gas outlet 16 and the semiconductor wafer 4 is smaller than that of the other gas outlet 1.
4.15 and the semiconductor wafer 4, a large amount of reaction gas flows into the exhaust passage 7, and the thermochemical reaction at the periphery of the wafer surface becomes weaker than at the center. .

Next, regarding another invention of the present invention, FIG. 2(a), Q)
). In the same figure, the gas tank designated by the reference numeral 21 has a plurality of gas introduction chambers 23 separated by a partition wall 22.
~25. And this gas tank 21
includes gas introduction ports 26 to 28 for introducing reactive gases into the gas introduction chambers 23 to 25, respectively, and gas ejection ports 29 to 31 for respectively spouting reactive gases onto the surface of the semiconductor wafer 4 on the heating stage 3. It is provided.

In the chemical vapor deposition apparatus configured in this manner, the amount of reaction gas ejected from each gas ejection port 29 to 31 to the semiconductor wafer 4 on the heating stage 3 during film formation can be changed. , the thickness of the produced film formed on the surface of the semiconductor wafer 4 can be set uniformly.

Although this embodiment shows an example in which the reaction gas exhaust passage 7 is formed around the heating stage 3, other inventions of the present invention are not limited to this (see Fig. 3). There is no problem even if the heating stage 30 is formed on both sides as shown in FIG.

In this case, the produced film A on the semiconductor wafer 4 is as shown in FIG.
) and (b), it is desirable to divide the gas ejection surface into a plurality of planar rectangular shapes as shown in FIG.

Further, in this example, the case where one type of reactive gas is used is explained, but another invention of the present invention is not limited to this, and even if multiple types of reactive gas are used, the same effect as in the example can be obtained. play. .

Furthermore, it goes without saying that the number of nozzles in the present invention and the number of gas introduction chambers in another aspect of the present invention are not limited to the embodiments described above.

〔Effect of the invention〕

As explained above, according to the present invention, the stage is provided in a reaction container and holds a wafer, and the gas tank is provided above the stage and stores a reaction gas therein. A plurality of nozzles each having a gas outlet for ejecting a reactive gas onto the surface of the wafer were installed so that they could move forward and backward, and each of these nozzles was formed by a box with a bottom that operated independently. and the distance between the semiconductor wafer on the stage can be changed. Another invention of the present invention is provided with a stage provided in a reaction container to hold a wafer, and a gas tank provided above the stage to store a reaction gas therein. The gas tank is provided with gas inlet ports that are defined in gas inlet chambers and that introduce reactive gases into these gas inlet chambers, and gas outlet ports that inject the reactant gases onto the wafer surface on the stage. At times, the amount of reaction gas ejected from each gas ejection port can be changed.

Therefore, the thickness of the produced film formed on the surface of the semiconductor wafer can be set uniformly, so that good film formation can be achieved.

[Brief explanation of the drawing]

FIGS. 1(a) and (b) are a sectional view and a bottom view of essential parts of a chemical vapor deposition apparatus according to the present invention, and FIGS. 2(a) and 2) are chemical vapor deposition apparatus according to another invention of the present invention. 3 is a cross-sectional view showing the Kiwasogun and a plan view of its main parts; FIG. 3 is a cross-sectional view showing the exhaust direction of the reaction gas in another embodiment; FIG.
) are a plan view and a sectional view showing the state of film formation in another example, FIG. 5 is a sectional view showing a gas ejection surface in another example, and FIG. A cross-sectional view showing the growth apparatus and a plan view of its essential parts, FIG. 7 is a cross-sectional view showing the direction of gas flow on the wafer surface, and FIGS. 8(a) and (
b) is a sectional view showing an example of defective film formation. 1... Reaction container, 3... Heating/heating stage, 4...
... Semiconductor wafer, 5... Gas tank, 11-1
3...Nozzle, 14-16...Gas outlet. Agent Daikimi Masuo Diagram Cb) ≦≧Mi=≦=To 4 Diagram Diagram Diagram Diagram

Claims (2)

[Claims] (1) A stage is provided in a reaction vessel to hold a wafer, and a gas tank is provided above the stage and stores a reaction gas therein, and the reaction gas is supplied to the surface of the wafer on the stage within the gas tank. 1. A chemical vapor deposition apparatus characterized in that a plurality of nozzles each having a gas ejection port are movable forward and backward, and each nozzle is formed by a box with a bottom that operates independently. (2) Equipped with a stage installed in a reaction container to hold a wafer, and a gas tank installed above the stage to store a reaction gas inside, and this gas tank is divided into multiple gas introduction chambers by partition walls. Chemical vapor deposition characterized in that the gas tank is provided with a gas inlet for introducing each of the reaction gases into these gas introduction chambers, and a gas ejection port for ejecting each of the reaction gases onto the surface of the wafer on the stage. Device.