JP2841583B2 - Vapor phase growth equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Summary] The present invention relates to a vapor phase growth apparatus used for manufacturing a semiconductor device and the like, and improves the film thickness distribution in a wafer so that the film thickness around the wafer does not become larger than a desired value. A reaction tube (1), double inner tubes (2A) and (2B) held substantially concentrically with the reaction tube in the reaction tube, and a plurality of tubes inside the double inner tube A susceptor (3) for holding the wafer (4) perpendicular to the axis of the double inner tube and spaced apart from each other, and a reaction gas introduction tube (10) for introducing a reaction gas into the upper inside of the double inner tube. 5) and an exhaust pipe (6) for exhausting gas from the lower part of the reaction tube. The double inner pipe is a double pipe slidable to each other and open at both ends. Vent (7)
Are opened, and the number of reaction gas flowing out from the double inner tube can be controlled by changing the number of openings penetrating through the double inner tube by sliding the double tubes with each other, and the numerical aperture is controlled by the reaction gas. The inlet side is configured so that it can be adjusted to be large and the exhaust side small.

[Industrial applications]

The present invention relates to a vapor phase growth apparatus used for manufacturing a semiconductor device and the like.

In recent years, with the miniaturization of LSIs, thinning of chemical vapor deposition films has been required. For this reason, a good distribution of several% is required for the film thickness distribution in the wafer for film formation.

INDUSTRIAL APPLICABILITY The present invention can be applied to a reduced pressure chemical vapor deposition apparatus having an improved film thickness distribution.

[Conventional technology]

 FIG. 4 is a perspective view of a conventional device.

As shown in the figure, a conventional reduced-pressure vapor deposition apparatus has a single-core reaction tube 1.
A plurality of wafers 4 are held vertically in the reaction tube, a reaction gas is introduced into the reaction tube through a reaction gas introduction tube 5, and the reaction gas is exhausted through an exhaust tube 6 to maintain the reaction gas pressure in the reaction tube at a predetermined value. The film was formed on the wafer 4.

FIG. 5 is a cross-sectional view illustrating the flow of a reaction gas in a conventional apparatus.

The reaction gas flows from the top of the reaction tube to the bottom as shown by the arrows.

[Problems to be solved by the invention]

As shown in FIG. 5, the flow of the reaction gas at this time has a large amount of gas around the wafer and a small amount of gas flowing around the center of the wafer. For this reason, the film thickness at the peripheral portion of the wafer tends to be larger than that at the central portion.

An object of the present invention is to improve the film thickness distribution in a wafer so that the film thickness around the wafer does not become larger than a desired value, and to improve the production yield.

[Means for solving the problem]

The above object is achieved by a reaction tube (1) and a double inner tube (2A), (2B) held substantially concentrically with the reaction tube in the reaction tube.
A susceptor (3) for holding a plurality of wafers (4) perpendicular to the axis of the double inner tube and spaced apart from each other inside the double inner tube; It has a reaction gas introduction pipe (5) for introducing a reaction gas inside, and an exhaust pipe (6) for exhausting from the lower part of the reaction pipe. A plurality of ventilation holes (7) are opened in each tube, and the number of holes passing through the double inner tube is changed by sliding the double tubes together. The numerical aperture is achieved by a vapor phase growth apparatus configured to be able to control the amount of reactant gas flowing out of the tube and adjust the number of reactant gas introduction sides to be large and the number of exhaust sides to be small.

The above-mentioned structure consists of the vents of the inner and outer pipes of the double inner pipe (7)
It becomes possible by changing the shape, number, and arrangement of the layers. Actual film-forming experiments are performed at various relative positions of the inner tube and the outer tube, and the relative position is optimized by obtaining the film thickness distribution.

[Action]

According to the present invention, a double inner tube is provided in a reaction tube, a wafer is placed in the double inner tube, a reaction gas is introduced into the double inner tube, and a plurality of ventilation holes are formed in the outer tube and the inner tube of the double inner tube. The amount of gas around the wafer was tested by changing the shape, number, and arrangement of the ventilation holes and sliding the double inner tubes together to adjust the numerical aperture through the double inner tubes. This is to improve the film thickness distribution in the wafer by reducing the thickness.

Further, in order to improve the film thickness distribution between the wafers, the double inner tube is configured so that the number of openings can be increased on the reaction gas introduction side and can be decreased toward the exhaust side.

〔Example〕

FIG. 1 is a perspective view of an apparatus according to one embodiment of the present invention.

A double inner tube 2A, 2
B, a plurality of wafers 4 are held vertically in the double inner tube in the double inner tube, a reaction gas is introduced into the double inner tube from the reaction gas introduction tube 5, and the double inner tube is The inside and outside are evacuated to form a film on the wafer 4 while maintaining the reaction gas pressure in the reaction tube at a predetermined value.

Each of the double inner pipes is provided with a large number of ventilation holes 7, and the number of openings (through holes) of the double inner pipe can be adjusted by sliding each other.

After the above adjustment, the opening of the double inner pipe should be large on the reaction gas introduction side and small on the exhaust side.

The reaction tube 1 is made of quartz, and the wafer 4 is held by a susceptor 3 made of quartz and heated from outside the reaction tube 1 by a resistance heating furnace.

Alternatively, the wafer 4 is placed on a susceptor 3 made of a material capable of high-frequency heating, and heated by high-frequency heating from outside the reaction tube.

 The double inner tube is made of quartz.

FIG. 2 is a sectional view for explaining the flow of a reaction gas in the apparatus of the embodiment.

The figure shows an example of the flow of the reaction gas. The reaction gas introduced into the double inner tube spreads to the center of the wafer as shown by the arrow, and the gas flow flows between the inner and outer tubes of the double inner tube. The system is divided into a system exhausted through the gap between the double inner tube and the reaction tube through the hole penetrating both, and a system exhausted through the gap around the wafer in the double inner tube. The distribution position is determined experimentally by adjusting the opening position of the through hole.

FIG. 3 is a diagram showing a film thickness distribution in a wafer of the embodiment and the conventional example.

The figure shows the film thickness distribution in a wafer when 50 6-inch wafers are simultaneously formed, (1) is an embodiment, and (2) is a conventional example.

Next, an example of the arrangement of the vent holes of the outer tube and the inner tube of the double inner tube is shown in FIG.

FIGS. 6 (1) and (2) are developed views showing examples of the arrangement of the vents of the outer tube and the inner tube of the double inner tube.

For the sake of simplicity, the figure shows a development view of the double inner tube corresponding to a case where 12 wafers are held at a pitch of 40 mm.

Fig. 6 (1) is a developed view of the inner pipe, all the vent holes are 5mm.
The round holes of φ are arranged at a pitch of 40 mm in the gas flow direction, and the number of vent holes is increased in three stages from the upstream side (upper side in the figure) to the downstream side of the gas.

The first stage was 90 mm pitch in the circumferential direction, the second stage was 57 mm pitch in the circumferential direction, and the third stage was 40 mm pitch in the circumferential direction.

On the other hand, Fig. 6 (2) is a developed view of the outer tube, in which all the vent holes are 5mm x 40mm elliptical holes arranged at 40mm pitch in the gas flow direction and 90mm pitch in the circumferential direction from the upstream side of the gas. They are arranged evenly toward the downstream side.

Here, the ventilation holes are staggered in every other row for both the inner pipe and the outer pipe.

With the above hole arrangement, by sliding the inner tube and the outer tube, the numerical aperture of the double inner tube in each of the above stages can be adjusted, and the numerical aperture on the downstream side can be made smaller than that on the upstream side.

In the embodiment, the numerical aperture of the double inner tube is adjusted, but the same effect can be obtained by adjusting the opening area instead.

〔The invention's effect〕

As described above, according to the present invention, the film thickness distribution in the wafer can be improved by preventing the film thickness around the wafer from becoming larger than a desired value, and the manufacturing yield can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view of an apparatus according to an embodiment of the present invention, FIG. 2 is a cross-sectional view illustrating the flow of a reaction gas in the apparatus of the embodiment, and FIG. FIG. 4 is a perspective view of a conventional apparatus, FIG. 5 is a cross-sectional view illustrating the flow of a reaction gas in the conventional apparatus, and FIGS. 6 (1) and (2) are double inner pipes. It is a development view which shows the example of arrangement | positioning of the vent hole of an outer tube and an inner tube. In the figure, 1 is a reaction tube, 2 and 3 are double inner tubes, 4 is a wafer, 5 is a reaction gas introduction tube, 6 is an exhaust tube, and 7 is a vent.

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-56-8814 (JP, A) JP-A-59-70760 (JP, A) JP-A-60-200522 (JP, A) JP-A 62-88 92430 (JP, A) (58) Field surveyed (Int. Cl. ⁶ , DB name) H01L 21/205 C23C 16/44 C30B 25/14 H01L 21/31

Claims (1)

(57) [Claims] 1. A reaction tube (1), double inner tubes (2A) and (2B) held substantially concentrically with the reaction tube in the reaction tube, and a plurality of sheets inside the double inner tube. A susceptor (3) for holding the wafer (4) perpendicular to the axis of the double inner tube and spaced apart from each other
A reaction gas introduction pipe (5) for introducing a reaction gas into the upper inside of the double inner pipe; and an exhaust pipe (6) for exhausting from the lower part of the reaction pipe. A double pipe open at both ends slidable at each end, wherein a plurality of vent holes (7) are opened in each pipe, and an opening penetrating through the double inner pipe by sliding the double pipes mutually. A vapor phase growth apparatus characterized in that the number of reactant gas outflows from the double inner tube can be controlled by changing the number of the reactant gas and the numerical aperture can be adjusted so that the number of reactant gas introduction sides is large and the number of exhaust gas sides is small. .