JPH0496322A - Apparatus for manufacturing semiconductor device - Google Patents

Abstract

PURPOSE:To form a film of uniform composition and thickness on a wafer by connecting one end of a funnel-like gas exhaust tube, which has a wall extended toward a wafer mount from the other end, to a gas introduction port and making a plurality of passage holes in the wall of the gas exhaust tube. CONSTITUTION:A gas exhaust port 21 completely covers a wafer mount 13. The wall of a funnel-like section is extended at an angle of about 30 deg. and five rows of about 5X5mm square passage holes 22 are made in the wall of the tube, each row consisting of 10-12 holes at appropriate distances between the rows. Mixed gas is introduced through the gas introduction port 15 with the temperature of a wafer 17 kept. In this time, the mixed gas flows downwards in the gas exhaust tube 16 along its wall. When the mixed gas reaches the funnel-like section, it spreads along the wall and a part of reactive gas flowing along the wall runs out through the passage holes 22. Thereby friction with the wall is decreased.

Description

[Detailed Description of the Invention] [Table of Contents] ・Overview, Field of Industrial Use, Conventional Technology (Fig. 4) ・Problem to be solved by the invention, Means for solving the problem, Operation, Examples (Fig. 4) Figure 1 - Figure 3) ・Effects of the invention [Summary] Regarding a semiconductor device manufacturing apparatus, more specifically, regarding a semiconductor device manufacturing apparatus that forms a film on a wafer by a vapor phase growth method, The purpose of the present invention is to provide a semiconductor device manufacturing apparatus that can form a film with a uniform composition and thickness, and includes a chamber, a wafer mounting table in the chamber, and a gas for introducing a reaction gas into the chamber. a funnel-shaped gas discharge tube having one end connected to the gas introduction port and a tube wall expanding from the one end toward the wafer mounting table; The structure includes a plurality of communication holes.

[Industrial application field]

The present invention relates to semiconductor manufacturing equipment, and more specifically, the present invention relates to semiconductor manufacturing equipment, and more specifically,
The present invention relates to a semiconductor device manufacturing apparatus that forms a film on a wafer using a vapor phase growth method.

Vertical vapor phase growth apparatuses are frequently used to form various films on wafers in the manufacturing process of semiconductor devices and the like. In particular, there is a need for a vapor phase growth apparatus that can form a compound semiconductor film with a uniform composition and thickness on a compound semiconductor substrate.

[Conventional technology]

Figure 4(a) shows a conventional example of vertical chemical vapor deposition (CVD).
) is a configuration diagram of the device.

In the figure (a), 1 is a chamber in which a film is grown on a wafer 7 by chemical vapor deposition under reduced pressure, and 2 is a wafer mounting table that rotates by a rotating shaft 3 during film growth. Further, reference numeral 6 designates a gas inlet 4 for introducing a reactive gas into the chamber 1 and a gas outlet 5 for discharging the reactive gas onto the wafer mounting table 2 in the chamber 1, both of which have the same diameter. It is a cylindrical conduit with a Further, 8 is a heater for promoting the chemical reaction of the reaction gas, 9 is a flange for holding the conduit 6 and sealing the inside of the chamber 1, and 10 is an outlet for the reaction gas.

However, there is a problem in that the grown film formed on the wafer 7 by this CVD apparatus is thick at the center of the wafer and thin at the periphery, as shown in FIG. 7(b). This shows that the reaction gas discharged from the conduit 6 does not flow laminarly, but protrudes at the center. For this, for example,
When a multilayer compound semiconductor film is continuously grown using this CVD apparatus, there is a problem that mixing occurs with the previously used reaction gas, resulting in non-uniform composition.

In order to solve this problem, as shown in Figure 4(c),
A CVD apparatus is used in which the gas discharge portion of the conduit 6 shown in FIG. 6(a) has been improved.

In the same figure (C), 11 is connected to the gas inlet 4,
This gas discharge tube has a funnel shape that widens toward the wafer 7 on the wafer mounting table 2, and is an improved gas discharge portion.

Figure 4(d) shows the in-plane distribution of the film created using this CVD apparatus. It has been improved.

[Problem to be solved by the invention]

However, due to the spread angle of the funnel-shaped gas discharge tube 11, a vortex of the reaction gas may be generated on the tube wall, and therefore, the reaction gas discharged from the discharge tube 11 toward the wafer 7 does not flow completely laminar. However, variations in film thickness and non-uniformity of composition still occur on the order of 20%. This poses a problem when further accuracy in film thickness is required or when improvement in film quality is required.

The present invention has been made in view of such conventional problems, and an object of the present invention is to provide a semiconductor device manufacturing apparatus that can form a film with a uniform composition and thickness on a wafer. .

[Means to solve the problem]

The above problem is solved by a wafer mounting table in the chamber, a gas introduction port for introducing a reaction gas into the chamber, and one end connected to the gas introduction port, and a pipe extending from the one end toward the wafer mounting table. The present invention is solved by a semiconductor device manufacturing apparatus characterized in that the gas discharge tube has a funnel-like shape with a widening wall, and a plurality of communication holes are provided in the wall of the gas discharge tube. 2. The semiconductor device according to claim 1, wherein the other end of the gas discharge tube extends along a side surface of the wafer mounting table and covers at least a wafer mounting surface of the wafer mounting table. Thirdly, the wafer mounting surface of the wafer mounting table of the station described in Claim 11 is provided vertically upward, and the gas discharge port of the gas discharge pipe is provided vertically downward. The problem is solved by a semiconductor device manufacturing apparatus that performs chemical vapor deposition of a film on a wafer surface.

[Effect]

According to the semiconductor device manufacturing apparatus of the present invention, a plurality of reflux holes are provided in the wall of the gas discharge tube, so that a part of the reaction gas flowing near the tube wall is transferred from the reflux hole to the outside of the gas discharge tube. leaks into Therefore, the gate friction between the reaction gas and the tube wall is alleviated, and the -like flow of the reaction gas can be maintained, so that no vortex is generated in the reaction gas. As a result, the flow rate of the reaction gas flowing through the gas discharge pipe becomes uniform, resulting in a laminar flow.

In addition, in the conventional case, it was difficult to extend the gas discharge port of the gas discharge pipe close to the wafer mounting table because the flow rate of the reaction gas was uneven. By making the flow velocity uniform, the gas discharge port can be extended to cover the wafer mounting table.

Therefore, when the funnel-shaped gas discharge port of the gas discharge pipe covers the wafer storage surface of the wafer mounting table, the reaction gas with a uniform flow rate is directly guided onto the surface of the J-I device.

This allows the wafer mounting surface to face vertically upward.
When applied to a vertical CVD apparatus in which the gas discharge port of the gas discharge tube is provided vertically downward, cavities with uniform film thickness and composition can be formed on the wafer J-.

〔Example〕

Hereinafter, a first embodiment of the present invention will be explained in detail with reference to the drawings.

Fig. 1 is a block diagram of a vertical CVD apparatus according to an embodiment of the present invention. 15c
13 is a rotating shaft 14t during film growth,
): Rotating wafer mounting table with a diameter of approximately 8 cm, 1
Reference numeral 5 indicates a gas introduction port for introducing a reaction gas into the chamber 12, and reference numeral 16 indicates the wafer mounting table 13, which is connected at one end to the gas introduction port 15 and faces the gas discharge port 21 from one end to the other end. It is a funnel-shaped gas discharge tube with a T-tube wall expanding toward the direction, and the gas discharge port 21 covers the wafer mounting surface of the wafer mounting table 13, and a plurality of communication holes 22 are formed in the tube wall of the gas discharge tube 16. is provided. Further, 18 is a heater that promotes the chemical reaction each time the wafer 17 is heated, 19 is a flange for holding the gas discharge tube 16 and sealing the inside of the chamber 12, and 20 is a flange for supplying the reaction gas to the outside of the chamber 12. D [is the outlet for discharging to the

Further, FIG. 2 is a perspective view illustrating details of the gas discharge pipe 16 used in the vertical CVD apparatus according to the embodiment of the present invention.

The same reference numerals as those in FIG. 1 indicate the same ones as in FIG. There is a lot of debris. In addition, the tube wall of the funnel-shaped part has a spread angle of about 30 degrees12, and there are about 10 to 12 rectangular communication holes 22 with sides of about 5 mm formed per circumference on the tube wall. ,
It is arranged over five circles with appropriate intervals between the circles.

Next, referring to FIGS. 3(a) to 3(c), a description will be given of the case where an nP substrate, 1nPIi layer, and 1nGaAs layer are sequentially grown on the wafer 7 using this CVD apparatus.

First, the wafer [R stand 13j1. :In
Several hundred P substrates (wafers) 17 are used. Next, Eva-mounted I
While rotating the F table 13, the wafer 17 is heated by the heater 1B, and the temperature is raised to about 600-650"C.

Next, maintain the temperature of 1-1: well, gas 10
A TMI (remethylindium)/PH5 (Bosphin) mixed gas is introduced from No. 15. At this time, the mixed gas flows down inside the gas discharge tube 16 along the tube wall. Then, when the mixed gas reaches the funnel-shaped part, the
), a part of the reaction gas that spreads along the tube wall and flows along the tube wall flows out from the flow hole 22. As a result, the friction generated between the tube wall and the tube wall is alleviated, so that the reaction gas does not generate vortices as in the conventional case. Therefore, as shown in FIG. 3(b), the flow velocity distribution becomes almost uniform on the wafer 17, and the surface of the wafer 17 has a uniform thickness of In.
PJii is formed.

Next, after forming an InP layer with a predetermined thickness, TMI/
A TEG (ethyl gallium)/AsHz (arsine) mixed gas is immediately introduced into the chamber 12 from the gas inlet 15 to start growing a 1nGaAs layer. At this time, the reaction gas is flowing in a layered manner inside the gas discharge tube 16 through the flow holes 22 provided in the tube wall, so that the TMI/TEG/^5 is mixed with the previously introduced TM I /P H and mixed gas.
) 13 There is almost no mixing with the mixed gas, which results in an InP layer and an InGaA layer having a uniform composition.
An s-layer can be formed.

FIG. 3(C) shows the in-plane thickness distribution of the InGaAs layer formed on the wafer 17 in this way from the surface of the wafer 17 to the uppermost communication hole 22 shown in FIG. 3(b). Using height (h) as a parameter, a comparison is made between a case where the height is an optimum value, a case where the height is lower than the optimum value, and a case where the height is higher than the optimum value.

According to the experimental results, the variation in film thickness is about -4% when the height is at the optimum value, about -14% when the height is lower than the optimum value, and about -14% when the height is higher than the optimum value. It is approximately +8%, and the uniformity is significantly improved in the case where the gas discharge tube 16 of the embodiment is used.

In the embodiment, the spread angle of the tube wall of the funnel-shaped portion of the gas discharge tube 16 is about 30 degrees, but it can be changed as appropriate depending on the reaction gas flow rate and other parameters. Also,
The shape, arrangement, and number of the passage holes in the tube wall can also be changed as appropriate.

〔Effect of the invention〕

As described above, according to the semiconductor device manufacturing apparatus of the present invention, since the plurality of communication holes are provided in the tube wall of the gas discharge tube, the friction between the gas discharge tube and the tube wall is alleviated. Therefore, the flow rate of the reaction gas flowing inside the gas discharge pipe becomes uniform, resulting in a laminar flow.

Further, since the funnel-shaped gas discharge port of the gas discharge pipe covers the wafer mounting surface of the wafer mounting table, the reaction gas with a uniform flow rate is directly guided onto the wafer mounting surface.

This allows the wafer mounting surface to face vertically upward.
When applied to a vertical CVD apparatus in which the gas discharge port of the gas discharge tube is provided vertically downward, a film with uniform thickness and composition can be formed on the wafer.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a vertical CVD apparatus according to an embodiment of the present invention. FIG. 2 is a perspective view of a gas discharge pipe used in a vertical CVD apparatus according to an embodiment of the present invention. FIG. 4 is a diagram illustrating film growth using a vertical CVD apparatus according to an embodiment of the invention, and FIG. 4 is a diagram illustrating a conventional CVD apparatus and a grown film distribution. [Explanation of symbols] 1.12...Chamber, 2.13...Wafer mounting table, 3.14...Rotating shaft, 4.15...Gas inlet, 5.21...Gas release Outlet, 6... Conduit, 7.17... Wafer, 8.18... Heater, 9.19... Flange, 10.20... Gas outlet, 11.16... Gas release Pipe, 22... communication hole.

Claims (3)

[Claims] (1) a chamber; a wafer mounting table in the chamber; a gas introduction port for introducing a reaction gas into the chamber; one end connected to the gas introduction port, and a wafer mounting table extending from the one end toward the wafer mounting table; 1. An apparatus for manufacturing a semiconductor device, comprising: a funnel-shaped gas discharge tube having a widening tube wall; and a plurality of communication holes provided in the tube wall of the gas discharge tube. (2) The semiconductor device according to claim 1, wherein the other end of the gas discharge tube extends along a side surface of the wafer mounting table and covers at least a wafer mounting surface of the wafer mounting table. Equipment manufacturing equipment. (3) The wafer mounting surface of the wafer mounting table according to claim 1 is provided with the wafer mounting surface facing vertically upward and the gas discharge port of the gas discharge tube facing vertically downward, and a film is formed on the wafer surface on the wafer mounting surface. Semiconductor device manufacturing equipment that performs chemical vapor deposition.