JPS62221128A - Treating apparatus - Google Patents

Abstract

PURPOSE:To make treatment uniform along the entire body of a material to be treated, by forming the flat surface for the supporting surface of a susceptor, and providing protruded parts for positioning the material to be treated. CONSTITUTION:In a CVD apparatus, e.g., a plurality of rotary shafts 9 are formed at an about equal interval in the circumferential direction at the outer peripheral part of a turntable 7. A susceptor 12, which supports a wafer 11 is a material to be treated, is horizontally supported on each rotary shaft 9. The susceptor 12 is arranged so that it is rotated on its axis and made to revolve around the lower edge of a buffer 6. The upper surface, which is the wafer supporting surface of the susceptor, is formed flatly. A plurality of protruded parts 13 are provided on the upper surface of the susceptor 12 so that the wafer 11 can be positioned in a concentric circle pattern. Therefore, a gas stream, which is guided to the directly upper part of the susceptor 12 by the buffer 6, flows on the wafer 11 in the laminar flow state without the effect of the group of the protruded parts 13. The gas is contacted with the entire body of the wafer 11 approximately uniformly owing to the rotation and revolution of the wafer 11. Thus the distribution of the film thickness becomes uniform along the entire body.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a processing technology, particularly a support technology for supporting a workpiece during processing. Concerning what is effective when used in generation technology.

[Conventional technology]

In the manufacturing of semiconductor devices, a CVD device that generates a CVD film on a wafer includes a processing chamber, a roughly triangular pyramid-shaped buffer arranged within the processing chamber, and a structure that rotates around the base of the buffer. The susceptor is equipped with a plurality of susceptors, and a wafer as a processing object is housed in a recess sunk in the main surface of the susceptor, and the wafer is rotated around its axis to carry out the desired biofilm treatment through a CVD reaction. There are some that are configured like this.

An example that describes CVD technology is "Electronic Materials November 1985 Special Issue" published by Kogyo Research Association Co., Ltd., November 20, 1985, P53.

[Problem that the invention seeks to solve]

In such a CVD apparatus, the flow of processing gas is affected by the opening edge of the recess sunk in the susceptor.
The present inventor has revealed that there is a problem in that the film thickness distribution on the wafer becomes non-uniform.

An object of the present invention is to provide a processing technique that can uniformize the processing over the entire object to be processed.

The foregoing and other objects and novel features of the invention will become apparent from the description herein and the accompanying drawings.

[Means for solving problems]

An overview of typical inventions disclosed in this application is as follows.

That is, the support surface of the susceptor is configured to be a flat surface, and a protrusion for positioning the object to be processed is provided in a protruding manner.

[Effect]

Since the support surface of the susceptor is formed flat, the processing gas flows smoothly over the object to be processed.

As a result, the processing gas comes into contact with the object to be processed evenly,
The processing thereby becomes uniform over the entire area.

〔Example〕

Fig. 1 is a vertical sectional view showing a CVD surface which is an embodiment of the present invention, Fig. 2 is an enlarged partial plan view showing the main parts thereof, and Fig. 3 is a front view taken along the line ■-■ in Fig. 2. The sectional views, FIG. 4, FIG. 5, FIG. 6, FIG. 7, and FIG. 8 are front sectional views and line diagrams for explaining the operation.

In this embodiment, this CVD apparatus is equipped with a chamber 1 having an exhaust port 2 at its lower part, and a bell jar 3 formed in the shape of a substantially triangular pyramid cylinder with an opening at the bottom is suspended at the upper part of the chamber 1. held.

A processing gas supply port 4 and an oxygen supply port 5 are provided concentrically at the top of the bell jar 3.
Buffers 6 are arranged concentrically within. The buffer 6 is formed into a substantially conical shape similar to the bell jar 3 and smaller in size by a predetermined size, and the conical surface thereof is curved in a concave shape.

On the other hand, a turntable 7 is supported horizontally at the lower part of the chamber 1, and the turntable 7 is configured to be rotated by a rotation drive device 8 consisting of a motor, a speed reduction mechanism, and the like. On the turntable 7, a plurality of rotating shafts 9 are arranged at approximately equal intervals in the circumferential direction on the outer periphery and are each supported substantially vertically, and each rotating shaft 9 is driven by a motor, a speed reduction mechanism, etc. It is configured to be rotated by the device 10. A susceptor 12 for supporting a wafer 11 as an object to be processed is supported horizontally on each rotating shaft 9, and the group of susceptors 12 revolves around the lower end of the buffer 6 while rotating on its own axis. It is arranged.

The susceptor 12 is made of quartz glass or the like and has a disk shape with a larger diameter than the wafer 11, and its upper surface, which is a wafer support surface, is formed into a flat surface. On the upper surface of the susceptor 12, a plurality of protrusions 13 (six in this embodiment) each having a substantially cylindrical shape with a rounded tip are arranged so as to position the wafer 11 concentrically. Each of the protrusions 13 is integrally protruded, and the height of each protrusion 13 is higher than the thickness of the wafer 11, and the pitch in the circumferential direction is smaller than the width of the orientation flat lla on the wafer 11. It is set as follows.

Heaters 14 are disposed below the susceptor 12, and these heaters 14 are used for the wafer 1 supported by the susceptor 12.
(2) It is constructed so that each can be heated.

Next, the effect will be explained.

The wafers 11 to be processed are supported in a mounted state on each susceptor 12 so as to be positioned by a group of protrusions 13. At this time, since the pitch of the group of protrusions 13 is set narrower than the width of the orientation flat 1laO of the wafer 11, the orientation flat l
Even if la is caught on one of the protrusions 13, the positioning of the wafer 11 is ensured by the remaining protrusions 13.

The wafer 11 supported by the susceptor 12 is heated by the heater 14 . If the wafer l1 is bent so that its peripheral portion is raised due to this heating, there is a risk that the wafer l1 will separate from the positioning of the protrusion 13 and fall off from the susceptor 12 as the susceptor 12 rotates around its axis. However, since the projections 13 are formed higher than the thickness of the wafer 11, even if warpage occurs, positioning and falling off will be prevented.

When the wafer 11 is set, the susceptor 12 is rotated around the buffer 6 by the turntable 7 and the rotating shaft 9. During this rotation and revolution, a processing gas such as silane and oxygen are supplied toward the buffer 6 from the supply ports 4 and 5, respectively.

The supplied processing gas flows down against the conical surface of the buffer 6, contacts the group of wafers 11 rotating around it, and is then exhausted from the exhaust port 2. A desired CVD film is generated on the wafer 11 by a CvD reaction when the processing gas comes into contact with the wafer 11 . At this time, the wafer 11
Since the wafer 11 rotates around its axis, the wafer 11 faces the gas flow evenly in all directions, and as a result, the film forming process using the gas is performed uniformly over the entire circumference of the wafer 11. .

By the way, as shown in FIG. 6, when accommodating and positioning the wafer 11 in the recess 13A of the susceptor 12A, the wafer 11 is placed in the susceptor 12A due to the clearance between the wafer 11 and the wafer 11 provided in the recess 13A. The inventor of the present invention has revealed that if the film is eccentrically positioned, the film thickness distribution becomes non-uniform, as shown in FIG.

That is, as the susceptor 12A rotates around the buffer 6, when the part of the wafer 11 that comes into contact with the inner circumferential surface of the recess 12A is located on the opposite side of the buffer, as shown in FIG. Since the gas flow from the buffer 6 rises under the influence of the opening edge of the recess 13A at this position, the film thickness on the wafer 11 corresponding to this position becomes thinner.

Furthermore, when the part of the wafer 11 that abuts the inner peripheral surface of the recess 12A is at the position of the buffer 6 as shown in FIG. 7, the outer peripheral part of the upper surface of the wafer 11 corresponding to this position is Since the gas flow from the buffer 6 is in the shadow of the recess 13A at this position, the film thickness becomes even thinner.

However, in this embodiment, the wafer 11 is placed on the main surface of the susceptor 12 formed on a flat surface, and the small-diameter protrusions 13
Since they are positioned in groups, the film thickness distribution is approximately uniform over the entire area, as shown in FIG.

That is, the susceptor 12 is guided by the buffer 6.
The gas flow guided directly above the wafer 11 flows over the wafer 11 in a laminar flow state almost unaffected by the group of protrusions 13.
Coupled with the i-revolution of , the contact is approximately uniform throughout, and the film thickness distribution becomes uniform over the entire surface.

In order to avoid the adverse effect of the group of protrusions 13 on the gas flow, it is desirable to keep the number of protrusions as small as possible (three or more necessary for positioning).

Further, when turbulence occurs in the gas flow, reaction products are generated as foreign matter, so the shape of the protrusion 13 should be formed into a cylindrical shape with a rounded end to suppress the turbulence of the gas flow. is desirable.

In this way, a laminar flow of gas can be ensured, so
The flow rate of nitrogen gas as a carrier gas can be reduced, and as a result, the amount of foreign matter depending on the flow rate of nitrogen gas can be reduced.

According to the embodiment described above, the following effects can be obtained.

By configuring the support surface of the susceptor to be a flat surface and protruding the protrusions for positioning, it is possible to suppress disturbances in the processing gas flow on the susceptor, so that the film formation process using gas on the wafer can be performed over the entire wafer. It can be made uniform.

(2) By uniformizing the film forming process over the entire main surface of the wafer, the film thickness distribution can be made uniform, so product yield, quality, and reliability can be improved.

(3) By making the protrusions higher than the wafer thickness,
Since it is possible to prevent the wafer from coming off the protrusion due to warpage due to heating during processing, it is possible to prevent the wafer from falling off from the susceptor or from being displaced.

(3) By forming the protrusion into a rounded cylindrical shape,
Since the turbulence of the processing gas flow can be further suppressed, the effects of (11, (2)) can be further enhanced.

(4) By setting the pitch of the protrusions to be narrower than the width of the orientation flat of the wafer, positioning can be ensured even when the protrusions overlap the orientation flat.

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 should be noted that various changes can be made without detracting from the gist of the invention. Not even.

For example, the protrusion is not limited to being formed integrally with the susceptor, but may be configured such that a bottle is inserted or screwed into a hole or screw hole formed in the susceptor.

The number of protrusions is not limited to six, nor is it limited to two or more protrusions, but they may be arranged in double or more by changing the radius.

In the above explanation, the invention made by the present inventor was mainly applied to the field of application which is the field of application, which is the rotation-revolution 2〇VD device. At least the present invention can be applied to all processing apparatuses having a susceptor that rotates around its axis.

〔Effect of the invention〕

A brief explanation of the effects obtained by typical inventions disclosed in this application is as follows.

By configuring the support surface of the susceptor to be a flat surface and protruding from this support surface for positioning the workpiece, it is possible to suppress the turbulence of the process gas flow on the susceptor. It is possible to uniformize the gas treatment over the whole area.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view showing a CVD apparatus which is an embodiment of the present invention, FIG. 2 is an enlarged partial plan view showing the main parts thereof, and FIG.
Front sectional views taken along line m-m in the figure, Figures 4, 5, and 6.
7, and 8 are front sectional views and line diagrams for explaining the functions thereof. DESCRIPTION OF SYMBOLS 1... Chamber, 2... Exhaust port, 3... Belljar, 4.5... Supply port, 6... Buffer, 7... Turntable, 8, 1O... Rotation drive device ,9...
Rotating shaft, 11... Wafer (workpiece), 12... Susceptor, 13... Protrusion, 14... Heater.

Claims (1)

[Claims] 1. The main surface of the susceptor that supports the object to be processed is formed as a flat surface, and a plurality of protrusions are protruded from the main surface to position the object to be processed. A processing device characterized by: 2. The processing apparatus according to claim 1, wherein the protrusion is formed to be higher than the thickness of the object to be processed. 3. The processing device according to claim 1, wherein the protrusion is formed in a cylindrical shape with a rounded tip. 4. The processing apparatus according to claim 1, wherein the projections are arranged such that the pitch thereof is narrower than the linear surface of the object to be processed.