JPS58197724A - Gas introducing tube for vapor growth apparatus - Google Patents

Abstract

PURPOSE:To uniformly supply reaction gas onto wafers by erecting a gas introducing tube within the bell jar forming a vapor growth apparatus, this tube is surrounded by a heating susceptor mounting semiconductor wafers, said gas introducing tube is extruded and hole diameter is gradually reduced while the holes becomes closer to the closed end of gas introducing tube on the occasion of boring many gas injection holes. CONSTITUTION:A gas introducing tube 7 of which upper end is closed is erected at the center of bell jar 5 having a gas exhaust port 4 at the side surface of bottom part. At the interim of introducing tube 7, a susceptor 9 having a heater at the lower end thereof surrounding such tube is provided horizontally and a plurality of semiconductor wafers 8 are placed thereon. Next, the gas introducing tube 7 is further extended upward and this tube is provided with many gas injection holes 2 of which diameter is gradually reduced as the holes is located closer to the upper end of tube 3. Accordingly, uniform thickness of thin film obtained by vapor growth can be obtained without relation to placing position of wafers 8.

Description

[Detailed description of the invention] [Technical field of invention] The present invention relates to a gas introduction pipe for vapor phase growth koji production.

[Technical background of the invention]

The conventional gas inlet pipe for vapor phase growth equipment is 1 example 11!3
As shown in the figure, a tube l with one end open and the other end closed.
A large number of gas ejection holes 2 having opening diameters of approximately the same size are bored on the circumferential surface of the gas-phase growth 'Ikal gas inlet pipe Jt', 112 reasons: As shown, the gas inlet pipe FC installed vertically through the central part of the pelger 1 having the bottom IN gas exhaust port 4 is inserted through the heater for supporting the naceptor. A gas inlet pipe 1 for a vapor phase growth apparatus is inserted into the leaf septa chamber on which a silver semiconductor wafer 1 is placed, and a reactant gas supplied from the gas inlet pipe R is inserted into the spacer.
Semiconductor sea urchin 88 is released by releasing gas from the gas outlet l.
It is formed from a predetermined #m film [vapor phase formation area].

[Problems with background technology]

The gas introduction tube 1 for vapor-phase growth koji production described above has a large number of gas injection holes 1 with a constant opening diameter, so it is a gas introduction tube for vapor-phase growth. Since the upward gas supply It (supply speed) to the sea urchin located in Karakura is small.
, the reaction gas cannot be ejected with a uniform ejection amount.
As a result, the semiconductor sea urchin 81 upper 6: formed thin 1 lil
Looking at the variations in the thickness values of 1&, as shown in Figure 3, 6, in the vicinity of the gas introduction pipe 1 for vapor phase growth ≦: on the arranged semiconductor tube 1, the thickness is smaller than the planned one thickness value. ±l for large values
There is a variation of more than 0° on the semiconductor wafer 8 placed far away from the gas introduction tube 1 for vapor phase growth, and there is a variation of more than ±10° at a value smaller than the planned film thickness value. As a result, the concentration of the gas ejected from the gas introduction pipe for a conventional vapor phase growth apparatus is uneven, so that the desired # film cannot be formed on the surface of the semiconductor wafer 5 with a uniform thickness, and the manufacturing process is delayed. There was a drawback that the yield was significantly reduced.

[Purpose of the invention]

In the present invention, the distance from the gas nozzle is 1llI≦2 regardless of the distance.

All positions 11t - surface of the semiconductor wafer arranged ≦2.

Vapor phase growth i! can easily form a thin film with uniform thickness! Its purpose is to provide gas for direct use.

[Summary of the invention]

In the present invention, a large number of gas ejection holes are bored on the circumferential surface of a tube with one end open and the other end closed, with the opening diameter gradually decreasing (2) on the closed end side (-approach T, C). In other words, the ejection pressure of the gas ejected from the gas ejection hole close to the closed lI#1ifNIII11 is increased.

All places l (= surface C of the placed semiconductor wafer.

This is a gas inlet tube for a vapor phase growth apparatus that can easily form a thin film with a uniform thickness.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.弗4 is the positive th1 factor in one embodiment of the present invention.

This gas introduction pipe 20 for a vapor phase growth apparatus has one end open,
Tube force with the other end closed F14WILi[+20ai'-
, a large number of gas ejection holes 2) are drilled in which the diameter of the opening becomes smaller from the opening side toward the closed end side. The reason why the diameter of is made small is to increase the pressure of the ejected reaction gas so that the reaction gas ejected from the gas ejection hole 21b on the open end side is at the same time as tTn t=fi. This is because the amount of gas ejected from the gas ejection hole 27m due to the smaller diameter is maintained at any arbitrary location on the same plane. The decrease is due to the gas vent JjagJl! 9 increases ≦Y. In other words, the gas ejection holes 11m approach the closed end IIIJ≦; 6: Therefore, if the diameter is set small, the number of holes drilled is The diameter of the gas ejection holes 21m and 21b is increased according to the reduction rate, and the number of holes from the open end side to the closed end side (-) is sparse and dense due to vapor phase growth. Gas introduction pipe 20 for ¥iii
C: It is preferable to set this by taking into consideration the amount of reactant gas to be supplied and the semiconductor wafer storage capacity of the vapor phase growth apparatus that uses this gas introduction pipe IO. Therefore, the gas injection hole j J As shown in the fifth factor, the number of holes 21'ak drilled in the closed proximal end side section; A predetermined opening may be provided, and a certain number of gas ejection holes jj'b with a large diameter may be bored in a sparse manner at the circumference Wt&+2/at2 on the opening end side.

For this purpose, the gas inlet pipe for vapor phase growth 'IIkIr constructed in this way was rebuilt and mounted on the susceptor 9 above the heater. Semiconductor wafers placed in 8 sections, vapor phase growth process number - 0 semiconductor wafers 8 where #il films were formed and their table [kIt dimorphic acid formed 1IllI! l
When examining the standard value of I-paired variation 1, the results shown by the characteristic line (11) in FIG. 6 were obtained.

As is clear from the figure, it was confirmed that regardless of the installation position of the semi-integrated wafer 8, #d was formed with a film thickness that was approximately equal to the reference value≦Y for all 1ltcD wafers. , the arrangement of the small-diameter gas ejection holes it's and the arrangement of the large-diameter gas ejection holes 11'b shown in FIG. A similar experiment was carried out with one gas inlet pipe 20' for a vapor growth apparatus separated at a predetermined interval at IY East and Chuo, and the results shown in the characteristic line (厘)≦2 in Figure 6 were obtained. As is clear from this characteristic line (Otori), there is a variation rate of ±511/J for the surface of the semiconductor wafer 1 at all placement positions kt2 with respect to the predetermined standard film thickness value range 2. It was found that a predetermined thin film was formed within the range of 42.According to the gas inlet pipe ZUI for this vapor phase growth apparatus, it was found that the vicinity of all the semiconductors 81 that were installed in the apparatus was ≦2, - Since the reaction gas of the foot violet can be supplied and its concentration can be easily set to a predetermined value, the installation position of the semiconductor sea urchin 8 is independent of 1it=≦Y.

A thin film of a predetermined thickness can be uniformly formed. As a result, the manufacturing yield can be significantly increased. [Effects of the Invention] As explained above, according to the present invention 6; It is possible to easily form a thin film having a uniform thickness on the surface of a semiconductor substrate, thereby increasing the manufacturing yield.

[Brief explanation of drawings]

Figure 141 is a front view of a gas introduction tube for conventional vapor phase growth*I[, and Figure 82 is a front view of a gas introduction tube for conventional vapor phase growth*I[.
The cross-section diagram IiI and the figure 3 are characteristic diagrams showing the relationship between the film thickness variation rate and the position of koji for semiconductor processing. Figure 4 shows the positive th+ factor and -5 factor of an embodiment of the present invention.
The top white diagram and the bottom 6 diagram of other examples of this shield are shown. Film thickness variation rate and installation position on semi-moving body sea urchin! ill: This is a characteristic diagram showing the co relationship. Takehiko Suzue, patent attorney for the applicant

Claims (1)

[Claims] The periphery of a tube with one end open and the other end closed is a surface (:. A gas ejection hole with a small opening diameter is formed from the open end side to the closed end side. A gas introduction pipe for a vapor phase growth apparatus that has a unique feature of having multiple holes.