JP3122477U - Connection structure between plate and cylinder in wafer heating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To alleviate stress concentration at a connection portion between a plate-like body and a cylindrical body of a wafer heating apparatus and prevent deterioration of quality due to generation of a crack.
A diameter-enlarged portion 221 that extends toward a plate-like body 21 is formed at an end portion of a cylindrical body 22 in a connecting portion, and a connection portion between the diameter-extended portion 221 and the plate-like body 21 is covered outside. To TIG welding 222.
[Selection] Figure 1

Description

  The present invention provides a disk-like plate-like body of a wafer heating apparatus for performing chemical vapor deposition (CVD) by heating a wafer adsorbed on an upper surface in a manufacturing process of a semiconductor wafer such as a silicon silicon wafer, and a cylindrical shape for supporting the plate-like plate-like body. Concerning connection structure with body.

In the manufacturing process of silicon wafers and the like, chemical vapor deposition is performed by adsorbing a wafer as a material on the upper surface of a disk-shaped wafer heating device (also referred to as a susceptor) in a vacuum chamber and heating the wafer.
A chemical vapor deposition apparatus described as “conventional technology” in Patent Document 1 will be briefly described with reference to the drawings.

FIG. 3 is a cross-sectional view showing an example of a chemical vapor deposition apparatus. 1 is a vacuum chamber, 11 is a gas supply hole for supplying gas into the vacuum chamber, 12 is an exhaust hole, 2 is a wafer heating device, and 21 is a disk-shaped device. A plate-like body, 22 is a cylindrical body that supports it, 23 is a resistance heating element, 24 is a power supply terminal, 25 is a lead wire, 26 is a temperature detection means such as a thermocouple, 27 is a lead wire, W is a wafer is there.
In this chemical vapor deposition apparatus, the inside of the vacuum chamber is depressurized by a vacuum pump (not shown), while a reaction gas of a film component is supplied into the vacuum chamber, and a desired surface is applied to the surface of the wafer W adsorbed on the plate-like body 21. A film is formed. In the case of plasma chemical vapor deposition, a voltage is further applied to the vacuum chamber to cause plasma discharge. The plate-like body 21 and the cylindrical body 22 are made of metal such as stainless steel or aluminum alloy, or ceramic.

  By the way, the portion of the plate-like body 21 of the wafer heating device 2 repeats high-speed temperature rise and high-speed temperature drop from room temperature to a high temperature of about 300 degrees by the resistance heating wire 231 in the operation cycle, but is not directly heated. Therefore, the temperature gradient is generated at these joints, and thermal stress tends to concentrate. According to the description of Patent Document 1, when the plate-like body 21 and the cylindrical body 22 are made of ceramic, a crack occurs in the joint portion, airtightness is impaired, and the degree of vacuum in the vacuum chamber is reduced. There is a problem in that the formed film and the accuracy of etching are adversely affected, and Patent Document 1 describes that the temperature gradient is alleviated by providing a sub-heater for heating the connecting portion.

On the other hand, in the metal wafer heating apparatus, the plate-like body 21 and the cylindrical body 22 are joined by welding. A general connection structure is shown in FIG. This figure is a partial cross-sectional view showing the connection part between the plate-like body 21 and the cylindrical body 22 in an inverted state. The plate-like body 21 is provided with a recess, the tip of the cylindrical body 22 is inserted, and the connection part is electronically connected from the outside. Joined by beam welding. Reference numeral 223 denotes an electron beam weld. Electron beam welding is easy to automate and can concentrate energy by focusing, so that penetration can be achieved over a depth of 20 to 30 mm, and accurate joining is possible, but the structure in which the cylindrical body is directly joined to the disk remains as it is Therefore, stress concentration is inevitable and cracks are unavoidable.
JP 2001-237051 A

The disk-shaped wafer heating device 2 that is the subject of the present invention is made of metal. In the case of metal, since the thermal conductivity is high, the temperature gradient is not as severe as in the case of ceramic heaters, but there is no change in the concentration of thermal stress at the joint, cracking occurs repeatedly, and the quality is adversely affected. It recognized.
An object of the present invention is to suppress the occurrence of cracks in such a metal wafer heating apparatus and improve the quality of a semiconductor wafer as a product.

  The present invention relates to a metal wafer heating apparatus used for chemical vapor deposition processing comprising a disk-like plate-like body that adsorbs a wafer on the upper surface and a cylindrical body that supports the wafer at the center position of the lower surface of the plate-like body. A plate-like structure in a wafer heating apparatus, wherein the plate-like body and the tubular body are connected to each other, and an enlarged-diameter portion that extends toward the plate-like body is formed at an end of the tubular body. In this case, the enlarged-diameter portion is a separate member from the tubular body, and the plate-like body and the tubular body in the wafer heating apparatus are welded and joined to the tubular body. A connection structure between the plate-like body and the tubular body in the wafer heating apparatus, which covers the connection portion between the enlarged-diameter portion and the plate-like body and is joined by TIG welding from the outside. Structure.

  According to the present invention, it is possible to suppress the occurrence of cracks in a metal wafer heating apparatus and to improve the quality of a semiconductor wafer as a product.

  According to the present invention, the stress concentration is alleviated by forming the enlarged diameter portion that extends toward the plate-like body at the end of the cylindrical body that is the connection portion between the plate-like body and the cylindrical body of the wafer heating device. The occurrence of cracks can be suppressed.

An embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a partial cross-sectional view showing a connecting portion between a plate-like body 21 and a cylindrical body 22 in an inverted state, and these materials are, for example, an aluminum alloy corresponding to JIS 6061. A diameter-enlarged portion 221 that extends toward the plate-like body is formed at the end of the cylindrical body 22, and the connection portion between the diameter-enlarged portion 221 and the plate-like body 21 is covered and joined by TIG welding from the outside. . 222 is a weld. Unlike electron beam welding, in which the base metal is melted and joined, TIG welding uses a wire, so that the bead swells in the welded portion, the shape of the connecting portion becomes smoother, and stress concentration is reduced.

  FIG. 2 is a partial cross-sectional view of a modified embodiment showing the same part as FIG. In this embodiment, the enlarged diameter portion 221 is not formed integrally with the cylindrical body 22, but is joined to the cylindrical body 22 by TIG welding as a separate member. As the material of the cylindrical body 22, a simple tubular material having no enlarged diameter portion can be used, so that the material yield is good. The other points are the same as those in FIG.

It is a fragmentary sectional view which shows the connection structure of an Example. It is a fragmentary sectional view which shows the connection structure of a modified example. It is sectional drawing which shows an example of the well-known chemical vapor deposition processing apparatus concerning this invention. It is a fragmentary sectional view which shows the conventional connection structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vacuum chamber 2 Wafer heating apparatus 11 Gas supply hole 12 Exhaust hole 21 Plate-shaped body 22 Cylindrical body 23 Resistance heating element 24 Feed terminal 25 (For power supply) Lead wire 26 Temperature detection means 27 (For temperature detection) Lead wire 221, 221a Widened portion 222, 222a, 222b Welded portion 223 Electron beam welded portion 235 Heat resistant rubber 236 Ceramic W Wafer

Claims (3)

  Used for chemical vapor deposition processing comprising a disk-shaped plate (21) that adsorbs a wafer (W) on the upper surface and a cylindrical body (22) that supports the plate (21) at the center of the lower surface of the plate (21). In the metal wafer heating device (2), the plate-like body (21) and the cylindrical body (22) are connected to each other, and the plate-like body (22) is connected to the end of the cylindrical body (22). 21) A connection structure between the plate-like body (21) and the cylindrical body (22) in the wafer heating apparatus, characterized in that an enlarged diameter portion (221) extending toward 21) is formed.   The plate-like body (21) and the cylinder in the wafer heating apparatus according to claim 1, wherein the enlarged-diameter portion (221a) is a separate member from the cylindrical body (22) and is welded to the cylindrical body (22). Connection structure with the state body (22). The plate-like body (21) and the cylindrical shape in the wafer heating apparatus according to claim 1, wherein the plate-like body (21) and the plate-like body (21) are connected to each other by TIG welding from the outside so as to cover the connection portion between the diameter-expanded portions (221, 221a). Connection structure with body (22).

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