JPH0578934B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a technology that is effective when applied to processing technology, particularly to a technology for processing semiconductor wafers used in the manufacture of semiconductor devices.

[Background Art] In the manufacturing process of semiconductor devices, a processing device such as a diffusion device or an oxide film forming device is used to perform predetermined processing on a semiconductor wafer made of silicon (Si).

Conventionally, such processing equipment has been used in which a processing tube called a process tube is placed horizontally, but in recent years, it has been
No. 54-20972, No. 53-144269, No. 52-127065,
A so-called vertical processing apparatus having a vertical process tube as shown in Japanese Utility Model Application Publication No. 51-134372 has been proposed.

The advantages of using the above-mentioned vertical processing equipment are: firstly, the length of the heater is shortened because the heat is trapped evenly within the process tube, and secondly, it is possible to save power. Second, since wafers can be taken in and out from the top or bottom of the process tube, there is no need for the jig or wafer to come into contact with the tube wall, making it difficult to damage the inside wall of the process tube. Third, the flat surface on which the equipment is installed is For example, it requires less area.

By the way, the above-mentioned vertical processing apparatus may be of a type in which a fluid supply port is provided at the upper part of the process tube and the fluid is caused to flow downward from the upper part inside the tube.

However, in the fluid supply mechanism of the above type, when the temperature of the processing fluid is lower than that of the processing space, the processing fluid supplied from the supply port falls rapidly.
It does not flow uniformly between wafers. The inventor has revealed that this results in non-uniform processing.

In addition to the above-mentioned publication, examples of vertical processing equipment that are explained in detail include "Electronic Materials
There is a separate issue of the November 1983 issue, "VLSI Manufacturing and Testing Equipment Guidebook", pages 75 to 79.

[Object of the Invention] An object of the present invention is to provide a processing technique that can perform uniform processing.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Summary of the Invention] A brief overview of typical inventions disclosed in this application is as follows.

That is, by supplying processing fluid upwardly and in opposite directions in the circumferential direction from a plurality of fluid supply ports into the upper part of a process tube whose upper end is closed, the processing fluid is stirred. After the concentration is made uniform, the solution flows over the surface of the object to be processed in the process tube, so that the processing can be made uniform.

In addition, by using a heater to heat the processing space of the process tube and preheating the processing fluid before supplying it to the inside of the process tube, the processing fluid is supplied into the tube in a heated state. Therefore, rapid descent of the processing fluid can be prevented and stable processing can be performed.

[Example] Fig. 1 is a sectional view showing a vertical diffusion device as an embodiment of the present invention, and Fig. 2 is a sectional view taken along the line -- in Fig. 1 showing the vicinity of the supply port of a fluid supply pipe.

The diffusion device 1 of this embodiment includes a cylindrical process tube 2 with one end open and the other end closed in a hemispherical shape.The process tube 2 is made of, for example, quartz glass, and the closed end side It is placed vertically upwards.

A processing space 3 is formed inside the process tube 2, and a heater 4 that heats the processing space 3 is installed around the outer periphery of the process tube 2 so as to surround the process tube.

Inside the processing space 3, a jig 5 made of quartz is supported by a loader 6 connected from below, and a plurality of semiconductor wafers 7, which are objects to be processed, are held in this jig 5, facing each other. ing.

The lower end opening of the process tube 2 constitutes a furnace port 8 for loading and unloading semiconductor wafers 7 together with a jig 5. A lid body 9 is removably attached to the furnace port 8. The opening 8 and the lid body 9 are not in close contact with each other, and have a gap or a discharge port 10 so as to gently exhaust the processing space 3. The lid body 9 and the process tube 2 form a processing apparatus main body.

The fluid supply pipe 11 runs between the heater 4 and the process tube 2 from the bottom to the top along the outer surface of the process tube 2, and is branched into two systems in the middle.
1a is formed. As shown in FIG. 2, each branch pipe 11a is bent in a V-shape into the processing space 3 near the hemispherical upper end of the process tube 2, and is inserted into the pipe wall in opposite directions, and each branch pipe 11a is inserted into the pipe wall in opposite directions. 12a,
Each of the tubes 12b faces diagonally upward so as to supply the processing fluid 13 along the inner circumferential wall surface.

Next, the operation of this embodiment will be explained.

When the semiconductor wafer 7 is held by the jig 5 and positioned in the processing space 3, the heater 4
is heated, and a processing fluid 13 such as nitrogen gas or oxygen gas is supplied into the processing space 3 from the supply ports 12a and 12b, and a desired impurity diffusion process is performed on the surface of the semiconductor wafer 7.

In this embodiment, the processing fluid 13 is supplied as follows.

First, the processing fluid 13 flowing through the processing fluid supply pipe 11 flows through each branch pipe 11a, 11b and reaches each supply port 12a, 12b. At this time, since each branch pipe 11a, 11b is arranged between the process tube 2 and the heater 4, the processing fluid 13 is preheated by the heater 4 while flowing through the branch pipe 11a, 11b.
In particular, in this embodiment, the processing fluid 13 is heated efficiently because of the branched piping structure.
Further, because of the branch piping structure, a large piping space is not required between the process tube 2 and the heater 4 compared to a single piping.

In this way, since the processing fluid 13 is preheated and has a temperature condition close to that of the processing space 3, it does not rapidly descend within the processing space 3 at the stage when it is supplied to the supply ports 12a and 12b. . Therefore, the processing fluid 13 flows gently between the semiconductor wafers 7, and uniform processing can be achieved.

In addition, in this embodiment, two supply ports 12a, 12
b are each opened diagonally upward of the processing space 3 and along the inner circumferential wall surface. Therefore, the processing fluid 13 supplied from the supply port 12a (or 12b) once flows obliquely upward along the inner circumferential side of the process tube 2. Then, each flow flows to the other supply port 1 at the part where it has flowed for about half a revolution.
It collides with the flow from 2b (or 12a),
The processing fluid 13 is stirred. The processing fluid 13 that has been stirred flows downward within the processing space 3. In this way, since the processing fluid 13 is once stirred within the processing space 3, the concentration distribution of the processing fluid 13 is made uniform. Therefore, uniform processing can be achieved.

In this way, the processing fluid 13 flows from top to bottom in the processing space 3 and reaches the discharge port 1 between the furnace mouth 8 and the lid body 9.
The air is gradually exhausted from 0.

〔effect〕

(1) The processing fluid is agitated by supplying the processing fluid from the fluid supply ports in mutually opposite directions in the circumferential direction and upward at the top of the process tube, and is supplied using a heater to heat the inside of the processing space. Since the processing fluid to be processed is preheated and then supplied from the fluid supply port,
The processing fluid is sufficiently stirred at the upper part of the process tube while being prevented from descending rapidly, and the processing fluid with a uniform concentration can be supplied to the object to be processed.

(2) Moreover, since the processing fluid is passed over the surface of the object to be processed in the process tube after the concentration has been made uniform, it is possible to achieve uniform processing.

(3) Since the processing fluid is prevented from rapidly descending within the processing space, stable processing can be performed.

(4) By installing a processing fluid supply pipe between the process tube and the heater installed outside of the process tube, the processing fluid can be preheated without the need for a dedicated heating means for preheating. .

(5) By forming the processing fluid supply pipe into a branch piping structure, the heating efficiency of the processing fluid can be improved.

(6) By forming the processing fluid supply pipe into a branch piping structure, pipe resistance can be reduced and stable processing fluid can be supplied.

Although the invention made by the present inventor has been specifically explained based on Examples above, the present invention is not limited to the Examples described above, and it is understood that various changes can be made without departing from the gist of the invention. Needless to say.

For example, the stirring means may be one that directly applies the fluid to the inner end surface of the process tube, and the end structure of the process tube is not limited to a spherical one.

Furthermore, the process tube may have a single supply port or three or more supply ports.

[Field of Application] In the above explanation, the invention made by the present inventor is mainly applied to the field of application, which is a so-called diffusion device, but the invention is not limited to this, for example, a low pressure CVD device. ,
This technique is also effective when applied to processing equipment such as annealing equipment or thermal oxidation processing equipment.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a vertical diffusion device as an embodiment of the present invention, and FIG. 2 is a sectional view taken along the line -- in FIG. 1 showing the vicinity of the supply port of a fluid supply pipe. 1... Diffusion device (processing device), 2... Process tube, 3... Processing space, 4... Heater, 5...
... Jig, 6 ... Loader, 7 ... Semiconductor wafer (workpiece), 8 ... Furnace mouth, 9 ... Lid, 10 ... Discharge port, 11 ... Fluid supply pipe, 11a, 11b ...
Branch piping, 12a, 12b... Supply port, 13...
processing fluid.

Claims (1)

[Scope of Claims] 1. A process tube having a processing space formed therein and disposed vertically with a closed upper end and an open lower end, and a lid that is detachably attached to the lower end and closes the opening. A fluid supply pipe for guiding the processing fluid is connected between the heater attached to the outside of the prosthetic tube and the process tube at the lower end of the processing device. The tip of the tube projects into the upper part of the process tube, and the tips of the tube are arranged circumferentially oppositely and upwardly along the inner wall surface of the process tube at the tip. A plurality of fluid supply ports for supplying processing fluid are provided above the object to be processed, and the processing fluid that has been stirred at the upper part of the process tube and then flowed downward in the processing space is provided. A processing device characterized in that a discharge port for discharging to the outside is formed in a lower part of the processing device main body. 2. The processing apparatus according to claim 1, wherein a hemispherical closed end is formed at the upper end of the process tube. 3. The processing apparatus according to claim 1, wherein the supply pipe is branched into a plurality of pipes.