JP2002057210A - Wafer-supporting unit and semiconductor manufacturing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wafer-supporting unit in a semiconductor manufacturing apparatus, having a lifting mechanism, capable of preventing flaws on the rear surface of a wafer and positional deviations of the wafer. SOLUTION: The wafer-supporting unit 14 is provided with a wafer-supporting main body 22, having a groove 30 for housing a recessed part 38 supporting the wafer W and a lift ring 32, and a plurality of lifting members 36, each extending from the internal peripheral edge of the lift ring and having the upper surface inclined downwardly. The lifting members can move vertically with the lift ring 32, and the surfaces of the wafer and the lift ring 32 are formed, so as to be flush with each other. Since the position, where the lift member is mounted and the upper surface thereof are inclined, the lifting member will not be brought into contact with the rear surface of the wafer but with only the outer peripheral lower edge of the wafer. Thus, flaws on the rear surface of the wafer can be prevented. Furthermore, an effect for preventing disturbance on the flow of processing gas by the wafer and the lift ring on the wafer-supporting main body can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a semiconductor manufacturing apparatus such as an epitaxial growth apparatus and a CVD apparatus, and a wafer supporting apparatus for supporting a wafer.

[0002]

2. Description of the Related Art There is a semiconductor manufacturing apparatus called a single wafer processing apparatus for processing silicon wafers one by one. In this single-wafer semiconductor manufacturing apparatus, usually, a wafer supporting device that horizontally supports only one wafer is provided in the processing chamber.

[0003] A general wafer supporting apparatus basically comprises a wafer supporting body on which a wafer is mounted, a so-called susceptor. Further, the wafer support device is provided with a lift mechanism for moving the wafer up and down with respect to the susceptor. A conventional general lift mechanism has a plurality of lift pins that extend through the susceptor. The wafer is placed on the upper ends of these lift pins, and the wafer can be moved up and down by moving the lift pins up and down. Has become. With such a lift mechanism, it becomes possible to transfer the wafer carried on the blade of the transfer robot onto the susceptor, or conversely, to transfer the wafer from the susceptor to the transfer robot.

[0004]

In the conventional wafer supporting apparatus as described above, when a wafer is supported,
The lift pins are located below the upper surface of the susceptor. Therefore, when the lift pins are lifted to lift the wafer from the susceptor, the upper ends of the lift pins hit the rear surface of the wafer, and the portion may be damaged. Scratches on the back surface of the wafer may adversely affect later processes.

In addition, when the wafer is moved up and down, only the upper end of the lift pin supports the back surface of the wafer, so that the wafer is likely to be misaligned.
The susceptor could run off the support area.

The present invention has been made in view of the above circumstances, and a main object of the present invention is to provide a wafer support apparatus having a lift mechanism capable of preventing scratches on the back surface of a wafer and displacement of the wafer. .

Another object of the present invention is to provide a semiconductor manufacturing apparatus provided with the above-described wafer support device.

[0008]

In order to achieve the above-mentioned object, the present invention provides a process chamber of a semiconductor manufacturing apparatus, having a concave portion on a top surface as a support area for supporting a wafer. A wafer support body in which a groove is formed on the upper surface outside the concave portion, a lift ring housed in the groove and capable of moving up and down, and integrally formed on the inner peripheral edge of the lift ring, from the outside of the concave portion A plurality of lift pieces having, on the upper surface, an inclined surface extending inward of the concave portion and inclined downward toward the inside, wherein the upper surface of the wafer is supported by the wafer while the wafer is supported by the concave portion. Substantially coplanar with the upper surface of the outer peripheral portion of the main body,
Further, the wafer support device is characterized in that the upper surface of the lift ring is substantially flush with the upper surface of the outer peripheral portion of the wafer support body when the lift ring is housed in the groove.

The lift piece replaces the conventional lift pin, and since the position of the lift piece and the upper surface thereof are inclined, the lift piece does not come into contact with the back surface of the wafer. It touches only the edge. Therefore,
The scratch on the back surface of the wafer can be prevented. Further, since the upper surface of the lift piece is higher toward the outside, the positional displacement in the horizontal direction can be suppressed.

It is preferable that the cross-sectional shape of the upper surface of the lift portion along the circumferential direction of the support area be curved upwardly. Thereby, the contact between the lift piece and the wafer becomes a point contact.

When the processing gas is introduced into the processing chamber and flows along the upper surface of the wafer support body, the upper surface of the lift ring and the upper surface of the wafer are flush with the upper surface of the wafer support body. The flow of the processing gas over the wafer maintains a laminar flow.

Further, when the claw member is disposed on the lift ring so as to be vertically movable at a position adjacent to the lift piece and the lift ring is lifted, the claw member is separated from the lift ring and further lifted. It is effective to In such a configuration, the horizontal movement of the wafer supported by the lift pieces can be prevented by the claw members arranged at a position higher than the wafer. In this configuration, when the lift ring is housed in the groove and the claw member is placed on the lift ring, the upper surface of the claw member is flush with the upper surface of the outer peripheral portion of the wafer support body. Is desirable to maintain the process gas in a laminar flow.

The present invention further relates to a semiconductor manufacturing apparatus having the above-structured wafer support apparatus in a processing chamber. As such a semiconductor manufacturing apparatus, for example, there is an apparatus of a type in which a processing gas flows along the upper surface of a wafer support body, such as an epitaxial growth apparatus.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 schematically shows an epitaxial growth apparatus as a semiconductor manufacturing apparatus on which a wafer supporting apparatus according to the present invention can be installed. The illustrated epitaxial growth apparatus 10 is of a single-wafer type for processing silicon wafers (not shown in FIG. 1) one by one, and includes a processing chamber 12 made of quartz glass. Is arranged. A processing gas inlet 16 is formed at the side of the processing chamber 12, and an exhaust port 18 is formed at a position facing the processing gas inlet 16. Further, the upper region and the lower region of the processing chamber 12, respectively,
A plurality of halogen lamps 20 are radially arranged.

In the epitaxial growth apparatus 10 having the above-described structure, the wafer is supported by the wafer support device 14, the halogen lamp 20 is turned on to heat the wafer, and the gas is exhausted from the exhaust port 18 while trichlorosilane (SiHCl 3) gas or the like. Dichlorosilane (SiH2C
l2) When a gas or the like is introduced from the inlet 16 as a processing gas, the processing gas flows in a laminar state along the surface of the wafer heated to a predetermined temperature, and a single crystal of silicon grows epitaxially on the wafer.

In such an epitaxial apparatus 10, the wafer support device 14 according to the first embodiment of the present invention is provided.
Has a susceptor 22 as a wafer support body as shown in FIGS. The susceptor 22 is a disk-shaped member made of a graphite material coated with silicon carbide, and is horizontally supported at three points from the back side by a quartz glass support shaft 24 erected below the processing chamber 12. ing. On the upper surface of the susceptor 22, a circular recess 2 is provided.
6 are formed. The recess 26 is a support area for accommodating and supporting the wafer W. The outer peripheral portion of the bottom surface of the concave portion 26 has an inclined surface 2 inclined downward toward the center side.
8 are formed. Therefore, the wafer W is transferred to the susceptor 22.
When the wafer W is disposed at a predetermined position in the recess 26, the wafer W is supported in a state where the outer peripheral lower edge (corner) of the wafer W is in contact with the inclined surface 28 on the outer periphery of the recess 26 (see FIG. 3A). . In this support state, the upper surface of the wafer W and the upper surface of the outer peripheral portion of the susceptor outside the concave portion 26 are substantially flush. This is to allow the processing gas introduced from the inlet 16 to flow while maintaining a laminar flow state.

On the outer peripheral portion of the susceptor 22, a substantially arc-shaped (C-shaped) groove 30 is formed concentrically with the susceptor 22. The arc angle of the groove 30 is preferably about 250 degrees. An arc-shaped or C-shaped lift ring 32 having substantially the same shape as the groove 30 is disposed in the groove 30.

The lift ring 32 constitutes a lift mechanism 34 for moving the wafer W up and down with respect to the susceptor 22. In a state where the lift ring 32 is housed in the groove 30,
For the same reason as described above, the upper surface of the lift ring 32 and the upper surface of the outer peripheral portion of the susceptor 22 are dimensioned to be flush with each other. That is, since the upper surface of the lift ring 32 is flush with the outer peripheral portion of the susceptor 22, the processing gas introduced from the introduction port 16 can maintain a laminar flow state. At the inner peripheral edge of the lift ring 32, three lift pieces 36 are integrally provided to protrude. The three lift pieces 36 are preferably provided at intervals of about 120 degrees. Each lift piece 36 extends inward (toward the center of the susceptor 22), and its tip reaches the inside area of the recess 26. A notch 38 having substantially the same shape as the lift portion 36 is formed in a portion of the susceptor 22 corresponding to the lift portion 36 so as not to hinder the accommodation of the lift ring 32 in the groove 30. .

The upper surface of the lift piece 36 is
Of the lift ring 3
In a state where 2 is accommodated in the groove 30, it is located below the bottom surface of the concave portion 26, at least the inclined surface 28 of the outer peripheral portion. Therefore, when supporting the wafer W on the susceptor 22, the wafer W does not come into contact with the lift piece 36.
The upper surface of the lift piece 36 is inclined downward toward the center of the susceptor 22. In addition, as can be understood from FIG.
Is a curved surface that is convex upward in the circumferential direction.

The lift ring 32 is moved up and down using the same means as in the prior art. More specifically,
As shown in FIG. 1, the lift mechanism 34 according to the first embodiment includes a vertically movable lift tube 40 arranged so as to surround a main shaft of the susceptor support shaft 24, and a drive for vertically moving the lift tube 40. The apparatus includes a device 42, three lift arms 44 radially extending from the lift tube 40, and a lift pin 48 suspended from a bottom surface of the groove 30 of the susceptor 22 through a through hole 46. Control the device 42 to control the lift tube 4
When the lift arm 44 and the lift arm 44 are raised, the lift pin 48 is pushed up at the tip of the lift arm 44, and as a result, the lift ring 32 is raised.

In order to support the wafer W on the wafer supporting device 14 having such a configuration, first, the transfer robot is operated, and the wafer W mounted on the blade 50 of the transfer robot is first operated.
At the position directly above the concave portion 26 of the susceptor 22. Next, the drive unit 42 of the lift mechanism 34 is controlled to raise the lift ring 32. At this time, since the blade 50 of the transfer robot is located at the open portion of the lift ring 32 (see FIG. 2), the lift of the lift ring 32 is not prevented. When the lift ring 32 rises to a position higher than the blade 50, the wafer W is transferred from the blade 50 to the lift piece 36 of the lift ring 32, and the wafer W is supported at three points (see FIG. 3B). . Lift piece 36
As described above, the upper surface of the wafer W is inclined downward toward the inside, so that the portion where the lift piece 36 contacts is only the outer peripheral lower edge of the wafer W. The inclination of the lift piece 36 also has a function of suppressing the horizontal movement of the wafer W. In addition, since the upper surface of each lift piece 36 is convexly curved, it contacts the wafer W at only one point. In addition, since a step is formed between the lift piece 36 and the lift ring 32, the positional deviation of the wafer W is also prevented by this, but the wafer W may exceed the step for some reason. Therefore, it is preferable to provide a projection as indicated by reference numeral 52 in FIG.

When the wafer W is supported by the lift pieces 36 of the lift ring 32, the blade 50 of the transfer robot is moved from above the susceptor 22 to the outside of the processing chamber 12, and the lift ring 32 is lowered. When the lift ring 32 is completely lowered into the groove 30, the lift piece 36 is located below the inclined surface 28 of the concave portion 26 of the susceptor 22, as shown in FIG. Is supported by the inclined surface 28 of the concave portion 26. Thereafter, the above-described epitaxial growth process is performed. Note that, as described above, the wafer W
, The upper surface of the lift ring 32, and the upper surface of the susceptor 22 at other positions are coplanar, so that the processing gas flowing on the wafer W maintains a laminar flow state.

When the wafer W is lifted from the susceptor 22 and transferred to the blade 50 of the transfer robot, it is easily understood that the lift mechanism 34 and the transfer robot may be operated in the reverse procedure.

FIG. 6 shows a wafer support device 114 according to a second embodiment of the present invention. In the second embodiment, the same or corresponding parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. The lift mechanism 134 in the wafer support device 114 of the second embodiment
Three claw members 133 are provided on the shaped lift ring 132. At the position of the lift ring 132 where the claw member 133 is located, a concave portion in which the claw member 133 is placed is formed. In a state where the claw member 133 is fitted into this concave portion (FIG. 6A), the first portion is formed. It has substantially the same shape as the lift ring 32 of the embodiment. Therefore, when the lift ring 132 is stored in the groove 30, the upper surface of the claw member 133 is
Are flush with the upper surface of the outer peripheral portion. Also, the claw member 13
3 is arranged at a position adjacent to the lift piece 36. Therefore, the number of the claw members 133 is the same as that of the lift piece 3.

A lift pin 48 is attached to the lift ring 132.
A through hole 60 is formed at a position where the upper end of the through hole contacts. The through hole 60 receives a flange 62 formed at the upper end of the lift pin 48, but has an inward flange 64 at the upper end so that the flange 62 can be lifted by the lift pin 48.

On the other hand, a counterbore 66 is formed in the claw member 133 at a corresponding position. The inside diameter of the counterbore 66 is substantially the same as the outside diameter of the upper end of the lift pin 48. Further, a cylindrical projection 68 is formed on a lower surface portion surrounding the counterbore hole 66. The cylindrical projection 68 is fitted into the through hole 60 of the lift ring 133 when the claw member 133 is placed on the lift ring 132.

In such a configuration, the lift pins 48
6A, the claw member 133 overlaps with the lift ring 132 as shown in FIG. 6A, so that the state is substantially the same as that of FIG. When the lift pin 48 is raised, the cylindrical projection 68 of the claw member 133 is first pushed up by the flange 62 of the lift pin 48. Thereby, only the claw member 133 rises and separates from the lift ring 133. In this state, the step between the upper surface of the lift member 36 and the upper surface of the claw member 133 becomes larger, and the effect of preventing the wafer W from moving in the horizontal direction increases. Therefore, it is not necessary to provide the projection 52 as shown in FIG. When the lift pin is further raised, the flange 62 of the lift pin 48 comes into contact with the lower surface of the flange 64 of the through hole 60, and the claw member 133 and the lift ring 132 rise integrally. Other operations are the same as in the first embodiment.

Although the preferred embodiment of the present invention has been described above, it goes without saying that the present invention is not limited to the above embodiment. For example, the semiconductor manufacturing apparatus of the above-described embodiment is an epitaxial growth apparatus, but the present invention is also applicable to an apparatus that performs other processing, such as a CVD apparatus.
The lift pieces need not be formed in a C-shaped lift ring. For example, a configuration in which a lift piece is directly provided at the upper end of each lift pin 48 can be considered.

[0030]

As described above, according to the present invention, when a wafer is supported by a wafer supporting body such as a susceptor or vice versa, the wafer is supported only by its lower peripheral edge. Because it is raised and lowered
The back surface of the wafer is not scratched. Although the wafer supporting apparatus of the present invention may damage the lower edge of the outer periphery of the wafer, the scratch at this portion does not cause any particular problem.

Further, in the wafer supporting apparatus according to the present invention, when the processing gas flows in a laminar flow along the upper surface of the wafer supporting body, the upper surface of the lift ring and the upper surface of the wafer are the same as the upper surface of the wafer supporting body. Because of the flat surface, the flow of the processing gas on the wafer can maintain a laminar flow.

Further, since the upper surface of the lift piece is an inclined surface which becomes higher toward the outside, it is possible to prevent horizontal displacement of the wafer, and to accurately place the wafer at a predetermined position on the wafer support body. Can be supported.

[Brief description of the drawings]

FIG. 1 is an explanatory view schematically showing an epitaxial growth apparatus to which a wafer support device of the present invention can be applied.

FIG. 2 is a plan view of the wafer support device according to the first embodiment of the present invention.

FIG. 3 is a sectional view taken along the line III-III in FIG. 2;
(A) shows a state where the wafer is supported on a susceptor,
(B) is a diagram showing a state where the wafer is lifted from above the susceptor.

FIG. 4 is a sectional view taken along the line IV-IV in FIG. 2;

FIG. 5 is an end view taken along the line VV in FIG. 2;

FIG. 6 is a view showing a wafer support device according to a second embodiment of the present invention, and is a sectional view similar to FIG. 3;

[Explanation of symbols]

10: semiconductor manufacturing apparatus, 12: processing chamber, 14, 1
14 wafer support device, 22 susceptor (wafer support body), 26 recess, 30 groove, 32, 132 lift ring, 34, 134 lift mechanism, 36 lift member,
133 ... claw member.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Youji Takagi 14-3 Shinizumi, Narita-shi, Chiba Pref. F-term (reference) 4G077 AA03 DA01 DB01 EG03 TF04 4K030 AA03 CA12 GA02 KA24 KA45 5F031 CA02 FA01 FA07 FA12 HA02 HA05 HA12 HA32 HA33 KA03 MA28 PA20 5F045 AA03 AB02 AC05 AF03 DP04 EK12 EK14 EM02 EM03 EM10 EN04

Claims (7)

[Claims] 1. A wafer support main body provided in a processing chamber of a semiconductor manufacturing apparatus, having a concave portion for supporting a wafer on an upper surface, and a groove formed on an upper surface outside the concave portion; And a lift ring that is vertically movable and that is integrally formed on an inner peripheral edge of the lift ring, extends from the outside of the recess to the inside of the recess, and slopes downward toward the inside. A plurality of lift pieces having an upper surface, wherein, in a state where the wafer is supported by the concave portion, the upper surface of the wafer is flush with the upper surface of the outer peripheral portion of the wafer support body, A wafer support device wherein an upper surface of the lift ring is flush with an upper surface of an outer peripheral portion of the wafer support body when the lift ring is housed in the groove. 2. The wafer supporting apparatus according to claim 1, wherein a cross-sectional shape of the upper surface of the lift piece along a circumferential direction of the concave portion is convexly curved upward. 3. The lift ring has a claw member that is vertically movable at a position adjacent to the lift piece, and when the lift ring is in a lifted state,
The claw member is configured to be further lifted separately from the lift ring. In a state where the lift ring is housed in the groove and the claw member is placed on the lift ring, 3. The wafer support device according to claim 1, wherein an upper surface of the claw member is flush with an upper surface of an outer peripheral portion of the wafer support body. A processing chamber; a wafer support body provided in the processing chamber, having a concave portion for supporting a wafer on an upper surface, and a groove formed on an upper surface outside the concave portion; A lift ring housed in the groove and capable of moving up and down; an inclination formed integrally with the inner peripheral edge of the lift ring, extending from the outside of the recess to the inside of the recess, and inclining downward toward the inside; A plurality of lift pieces each having a surface on the upper surface thereof, wherein the upper surface of the wafer is flush with the upper surface of the outer peripheral portion of the wafer support body in a state where the wafer is supported by the concave portion. A semiconductor manufacturing apparatus wherein an upper surface of the lift ring is flush with an upper surface of an outer peripheral portion of the wafer support body when the lift ring is housed in the groove. 5. The lift ring has a claw member vertically movable at a position adjacent to the lift piece, and when the lift ring is in a raised state,
The claw member is configured to be further lifted separately from the lift ring. In a state where the lift ring is housed in the groove and the claw member is placed on the lift ring, 5. The semiconductor manufacturing apparatus according to claim 4, wherein an upper surface of the claw member is flush with an upper surface of an outer peripheral portion of the wafer support body. 6. The semiconductor manufacturing apparatus according to claim 4, wherein a processing gas introduced into the processing chamber flows along an upper surface of the wafer support body. 7. The apparatus according to claim 6, wherein the apparatus is an epitaxial growth apparatus.
4. The semiconductor manufacturing apparatus according to claim 1.