JPS6355192A - Normal-pressure vapor growth apparatus - Google Patents

Abstract

PURPOSE:To prevent contamination of a wafer in the normal pressure vapor growth, by using an upwardly directing reaction gas blasting port of a dispersion head, placing a susceptor just above the blasting port and placing a wafer on the susceptor. CONSTITUTION:A reaction gas blasting port 13a of a dispersion head 13 is directed upward and a susceptor 12 is placed just above the head 13 in a manner movable along horizontal direction 17. The susceptor 12 has a through-hole 12a and a hollow part 12b at the circumference of the through-hole 12a. A wafer 11 is attached to the susceptor 12 exposing the element-forming face 11a of the wafer 11 downward. Since the reaction gas is blasted from the bottom to the to against the wafer 11, the contamination of the surface of the wafer with a reaction product can be prevented even if the reaction product is attached to the circumference of the dispersion head 13.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to semiconductor manufacturing equipment, and particularly to a semiconductor manufacturing equipment designed to prevent particle adhesion and contamination to wafers during normal pressure vapor phase growth.

[Prior Art] Chemical vapor deposition (CVD) processes are used for various purposes in the manufacturing process of semiconductor devices. Among them, the atmospheric pressure vapor deposition method is used for forming the surface protective film of the interlayer insulating film 2, etc., because it allows film formation at a relatively low temperature, has a fast growth rate, and provides a high throughput.

As shown in FIG. 3, a conventional atmospheric vapor phase growth apparatus uses a susceptor 22 made of silicon carbide (S i C) or Inconel.
Place the wafer 21 directly on top of the susceptor 2, and place the susceptor 2 directly under the reaction gas outlet 23a of the dispersion head 23.
2 passes through the wafer 21, and an oxide film (SiO2), a phosphosilicate glass film (PSG), etc. are formed on the wafer. At this time, the wafer 21 is a susceptor.
It is heated by a heater 26 at the bottom of 22.

[Problems to be Solved by the Invention] In the above-mentioned conventional atmospheric pressure vapor phase growth apparatus, the element formation surface (surface) of the wafer 21 faces upward, so reaction products adhering to the periphery of the dispersion head during film formation occur. Particles were sometimes attached to the element formation surface (surface) of the wafer due to the falling of the wafer. In addition, reaction products are deposited thickly on the susceptor because the reaction gas is constantly blown onto the susceptor, and as the number of growths increases due to the fall of the reaction products adhering to the area around the dispersion head mentioned above, the susceptor surface gradually becomes more dirty. It's coming. Placing a wafer directly on such a susceptor also adversely affects post-processing due to contamination of the wafer backside.

An object of the present invention is to provide an atmospheric vapor phase growth apparatus that prevents wafer contamination.

[Differences between the invention and the prior art] Compared to the above-mentioned conventional atmospheric vapor phase growth apparatus, the present invention has an original content in that the positional relationship between the wafer and the dispersion head is reversed.

[Means for Solving the Problems] The present invention provides a dispersion head with a reactive gas outlet facing upward, a susceptor placed directly above the head, and a susceptor with the element forming surface of the wafer facing downward. This is a normal pressure vapor phase growth apparatus characterized by being provided with a mounting portion for holding the wafer toward the wafer.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

(Example 1) As shown in FIG. 1, in this example, the reaction gas outlet 13a of the dispersion head 13 is installed upward,
A susceptor 12 is installed directly above the head 13 so as to be movable in the horizontal direction 11. The susceptor 12 is provided with a through hole 12a that penetrates vertically, and a recess 12b is provided at the periphery of the through hole 12a on the upper surface of the susceptor. The structure is such that the element forming surface 11a faces the through hole 12a and is exposed downward. Further, a heater 16 is installed above the susceptor 12.

In the embodiment, the wafer 11 is fixed to the susceptor 12 with its element forming surface (front surface) 11a facing the through hole 12a of the susceptor 12 and exposed downward.

The wafer 11 is heated by a heater 16 located above the susceptor 12. Dispersion head 13
is placed below the wafer 11 and the susceptor 12, and the reaction gas is blown out from the bottom to the top toward the wafer, so even if reaction products adhere to the periphery of the dispersion head 13, they will not reach the wafer surface. It will not stick. Further, unreacted gas is immediately exhausted from the exhaust port 14 as shown by arrow 15. Furthermore, the back side of the wafer is not in contact with anything, so it is not contaminated.

(Example 2) FIG. 2 is a sectional view of a second example of the present invention, which also relates to the reaction section. This is basically the same as the above embodiment, but the gas outlet 13a of the dispersion head 13 is curved to concentrate the gas flow to one point, thereby preventing gas diffusion and improving film thickness uniformity. I can buy things.

[Effects of the Invention] As explained above, in the present invention, since the film is grown with the element surface of the semiconductor substrate facing downward, it is possible to prevent particles from adhering to the surface of the semiconductor substrate, and also to prevent contamination of the back surface. It has the effect of making it possible.

[Brief explanation of the drawing]

1 and 2 are cross-sectional views showing an embodiment of the present invention, and FIG. 3 is a cross-sectional view showing a conventional example.

Claims (1)

[Claims] (1) The reaction gas outlet of the dispersion head is installed facing upward, a susceptor is arranged directly above the head, and a mounting part that holds the wafer on the susceptor with the element forming surface of the wafer facing downward. An atmospheric pressure vapor phase growth apparatus characterized by being provided with.