KR100702756B1 - Heater unit for semiconductor processing - Google Patents

Abstract

The present invention can raise the temperature at the time of heating early, and can uniformize the heat over the entire surface, and in addition, the choice of the material of the metal base and the heater is wide, and depending on the material, it can also be used in a high temperature region. In addition, the present invention provides a heater unit having high thermal conductivity and high durability and a method of manufacturing the same.

In addition, the present invention is the front surface of the lower base, the upper base and the heater of the heater unit in which the linear heater is incorporated in the path defined between the lower base and the upper base made of metal in one or both of the bases in a plastic deformation state. By joining and integrating by any one of brazing, soldering, and diffusion bonding over, the thermal conductivity between both bases becomes good, so that local deformation and residual stress due to local temperature rise do not occur, Damage to the heater can also be prevented. In addition, a wider selection of metal-based materials can be used, and for example, stainless steel and titanium-based materials can be used in high temperature regions.

Description

Heater unit and its manufacturing method {HEATER UNIT FOR SEMICONDUCTOR PROCESSING}             

1 is a cross-sectional view showing a schematic structure of a junction heater unit to which the present invention is applied;

2 is an enlarged view of the heater of FIG. 1;

3 is a view showing the relationship between the shape, size, and manufacturing procedure of the heater and each base before bonding;

4 is a view similar to FIG. 3 showing a modification of the heater unit according to the present invention;

5 is a sectional view showing a schematic structure of a conventional injection type heater unit;

6 is a cross-sectional view showing a schematic structure of a conventional bolted heater unit;

7 is a sectional view showing a schematic structure of a conventional welded heater unit.

Explanation of symbols for the main parts of the drawings

l: Bonded heater unit 2, 14, 17: Lower base

2a, 14a, 17a: groove 3, 15, 18: upper base

4: sheath heater 5: nichrome wire

6: protective pipe 7: magnesium oxide powder

8: junction 11: injection heater unit                 

l2: stainless sheath heater 13: bolted heater unit

16: welded heater unit 19: peripheral portion

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heater unit incorporating a heater in a base made of metal for use in a semiconductor processing apparatus and the like, and a manufacturing method thereof.

Background Art Conventionally, heater units incorporating a heater in a metal base have been used in various fields such as susceptors such as semiconductor processing apparatuses and electrostatic chucks. In the heater of such a heater unit, a sheath heater made of stainless steel is generally used. The stainless sheath heater is injected into aluminum (injection type), the stainless sheath heater is inserted into an aluminum or stainless steel plate, and bolted (bolted) or the outer circumference of the inserted plate is welded (welded). Configure

The schematic structure of the conventional injection type heater unit 11 which incorporates the stainless sheath heater 12 in FIG. 5 is shown. The stainless sheath heater 12 passes the heating element in a stainless steel protective pipe to electrically insulate the two with an insulating material. The heater unit 11 is manufactured by bending this pipe-shaped stainless sheath heater 12 in a predetermined pattern, injecting it into an aluminum base, and processing such as cutting and surface polishing.                         

6, the schematic structure of the conventional bolted type heater unit 13 is shown. In this structure, the metal sheath is divided into two vertically, the same sheath heater 12 is provided in the groove 14a formed in the lower base 14 made of aluminum, stainless steel, or the like, and the upper base 15 is closely attached. The bolts are integrated by bolts in place.

7, the schematic structure of the conventional welded heater unit 16 is shown. Also in this structure, the metal base is divided into two vertically, the same stainless sheath heater 12 is provided in the groove 17a formed in the lower base 17 made of aluminum, stainless steel, or the like, and the upper base 18 is attached. The film is brought into close contact with each other to be integrated by welding only at the edge portion 19.

In the above structure, the injection type heater unit has good thermal conductivity of the heater because the heater unit is in close contact with the aluminum casting. However, since the aluminum is used as the metal base, its melting point is low (generally about 540 ° C.), 500 There is a problem that it is difficult to use in an environment of not lower than ℃. Moreover, since the injection temperature of aluminum is 700 degreeC or more, the metal which can be used for the protection pipe of a sheath heater is limited to stainless steel, Inconel material, etc. with high melting point. In addition, since the coefficient of thermal expansion between the metal used for this protective pipe and aluminum as a metal base is different, the heater deforms due to the thermal stress at high temperatures, and the wire is disconnected due to repeated use. There is a problem of deformation.

On the other hand, the bolt-mounted heater unit of aluminum base has the same use temperature as the injection type heater unit, and since the restraint of the sheath heater by the base is physical, the influence of the thermal expansion difference caused by the temperature difference at the time of use and the use is It becomes small and there exists an advantage that disconnection is hard to produce at the time of repeated use.

However, since there is a gap in the groove, and the gap is a heat insulating layer and each part is in physical contact with each other, the adhesion between the upper and lower bases and the sheath heater or the base is low, so that the thermal conductivity is poor, and in some cases, the temperature is locally raised. There is a problem of damaging the heater. The same applies to the welded heater unit. In addition, the welded heater unit also has a large distortion due to welding, and has a problem in terms of shape retention.

The present invention has been made in view of the above-described problems of the prior art, and it is possible to raise the temperature early at the time of heating and to equalize the heat over the entire surface. In addition, the degree of freedom of selection of the material of the metal base and the heater is high. Accordingly, an object of the present invention is to provide a heater unit capable of being used in a high temperature region, having good thermal conductivity, and having high durability and a method of manufacturing the same.

The above object is a heater unit in which a linear heater is embedded in a path defined between an upper base made of metal in the same manner as the lower base made of metal, and between the lower base and the upper base and between the heater and the respective bases. A heater unit, and between the respective bases and between the heaters and each of the bases in a vacuum, the spaces being joined by any one of brazing, soldering, and diffusion bonding over the entire surface of the opposite surface. Or by one of brazing, soldering, and diffusion bonding over the entire surface of the opposing face in a state of plastic deformation of one or both of the parts in contact with each other by pressurizing under a predetermined gas atmosphere. Is achieved. In particular, the heater may be formed by accommodating a heating element in a metal pipe and at the same time having an insulator filled therein, and a passage defined in one or both of the bases is smaller than that of the heater, and between and between the bases. One or both of the parts in contact with each other due to the pressurization between the heater and the respective bases may be joined in a plastically deformed state.

The above and other objects, features, aspects, advantages, and the like of the present invention will become more apparent from the following detailed embodiments described with reference to the accompanying drawings.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the present invention.

1 shows a schematic structure of a bonded heater unit 1 to which the present invention is applied. In this structure, the metal base is divided into two parts in the vertical direction, and the grooves 2a formed in the lower base 2 made of any one of aluminum, aluminum alloy, copper, copper alloy, stainless steel, nickel-based alloy, titanium, and titanium alloy are formed. The sheath heater 4 mentioned later is provided, and between the lower base 2 and the upper base 3 which consists of a homogeneous or different material, and between the sheath heater 4 and each base 2 and 3 over the whole surface ( Joining part 8 shown by a thick line is joined by brazing, soldering, or expansion joining, and is integrated.

2 shows an enlarged schematic sectional view of the sheath heater 4 interposed between the lower base 2 and the upper base. The nichrome wire 5 serving as a heating element is passed through a protective pipe 6 made of a material selected from aluminum, aluminum alloy, copper, copper alloy, stainless steel, inconel, titanium, and titanium alloy to protect the nichrome wire 5 and the nichrome wire 5. Between the pipes 6, magnesia powder 7 is filled in order to electrically insulate between them. If the protective pipe 6 of the sheath heater 4 is combined with the bases 2 and 3 and the same material, there is no distortion due to the difference in thermal expansion between both during heating and cooling.

Next, the manufacturing procedure of the junction type heater unit 1 is demonstrated. As shown in FIG. 3, even if the semi-circular groove 2a previously formed in the lower base 2 presses the sheath heater 4 in the upper end of the upper base 3 of the lower base 2, even if it presses in, It is about the size which protrudes slightly from the joining surface, and the groove | channel is not formed in the upper base 3 before joining.

First, in the case of brazing and soldering, solder is applied before pressing the sheath heater 4 into the groove 2a, and the sheath heater 4 is pressed into the groove 2a of the lower base 2, and the vacuum state is applied. Alternatively, the upper base 3 is extended and pressurized in an atmosphere such as nitrogen, as indicated by an arrow, and the upper base 3 is diffusion bonded while plastically deforming (FIG. 2). Accordingly, since the lower base 2, the upper base 3, and the sheath heater 4 are in close contact with each other at the front thereof, only the bolt fastening type and the outer circumferential portion where the two bases 2 and 3 are in close physical contact with each other. Heat transfer losses are less likely to occur compared to welded welds. Therefore, it becomes possible to heat to high temperature with little heater capacity. Moreover, the power density of a heater can be reduced, local abnormal heat generation of a heater can be avoided, and disconnection by this can be prevented.

In addition, you may change arbitrarily, for example, making the shape of a sheath heater into a substantially triangular cross section as shown in FIG. In addition, pressurization of a heater and pressurization of a junction may be performed simultaneously. In addition, the shape of the base may be circular, square, or the like.

As apparent from the above description, according to the heater unit and the manufacturing method thereof according to the present invention, the lower base and the upper base of the heater unit in which a linear heater is embedded in a path defined between the lower base and the upper base made of metal; By joining and integrating the heater by any one of brazing, soldering, and diffusion bonding over its entire surface in the state of plastic deformation of one or both of the bases, the thermal conductivity between both bases is improved, and localized by local temperature rise. Since deformation and residual stress do not occur, deformation and damage to the heater can also be prevented. In addition, the degree of freedom of selection of the material of the metal base is increased, and for example, use of stainless copper or titanium-based materials enables use in a high temperature region.

As mentioned above, although the invention made by this inventor was demonstrated concretely according to the said Example, this invention is not limited to the said Example and can be variously changed in the range which does not deviate from the summary.

Claims (12)

A lower base made of a metal having a flat upper surface, An upper base having a flat lower surface and made of the same metal, An electrothermal heater element disposed in a groove defined between the bases Has, Opposite surfaces of the lower base, the upper base, and the heater element are joined to each other almost over the entire surface by metal bonding. At least one of the upper surface of the lower base and the lower surface of the upper base is plastically deformed and adapted to the contour of the electrothermal heater element. Heater unit characterized in that. The method of claim 1, And the metal joint comprises a member selected from the group consisting of brazing, soldering and diffusion bonding. The method of claim 1, The electrothermal heater element comprises a sheath heater having a metallic sheath pipe, a resistance heater wire contained within the sheath pipe and an insulating material filled in the sheath pipe to electrically insulate the resistance heater wire from the sheath pipe. Heater unit. The method of claim 3, wherein The metal sheath pipe is a heater unit comprising a material selected from the group consisting of aluminum, aluminum alloy, copper, copper alloy, stainless steel, inconel, titanium and titanium alloy. The method of claim 1, And the upper base and the lower base are each made of a material selected from the group consisting of aluminum, aluminum alloy, copper, copper alloy, stainless steel, nickel-based alloy, titanium and titanium alloy. As a manufacturing method of a heater unit, Preparing a lower base of a metal having a flat upper surface, Preparing an upper base of a metal having a flat lower surface, Disposing the upper base on the lower base such that an electrothermal heater element is positioned between the upper and lower surfaces of the lower and upper bases; At least one of the upper surface of the lower base and the lower surface of the upper base is plastically deformed to adapt to the contour of the heater element, and the opposing surfaces of the lower and upper bases and the electrothermal heater element are substantially bonded by metal bonding. Characterized in that bonded to each other over the entire surface Method of manufacturing the heater unit. The method of claim 6, And the metal joint is made of a member selected from the group consisting of brazing, soldering and diffusion bonding. The method of claim 6, The electrothermal heater element includes a sheath heater comprising a sheath heater made of a metal sheath pipe, a resistance heater wire contained within the sheath pipe and an insulating material filled in the sheath pipe to electrically insulate the resistance heater wire from the sheath pipe. Manufacturing method. The method of claim 8, And said metal sheath pipe is made of a material selected from the group consisting of aluminum, aluminum alloy, copper, copper alloy, stainless steel, inconel, titanium and titanium alloy. The method of claim 6, And the upper base and the lower base are each made of a material selected from the group consisting of aluminum, aluminum alloy, copper, copper alloy, stainless steel, nickel-based alloy, titanium and titanium alloy. The method of claim 6, At least one of the upper surface of the lower base and the lower surface of the upper base is provided with a groove for receiving the heat transfer heater element substantially closely before the plastic deformation. The method of claim 6, At least one of the upper surface of the lower base and the lower surface of the upper base is adapted to receive only a portion of the cross section of the heat transfer heater element closely prior to the plastic deformation and to expose the remaining cross section portion of the heat transfer heater element. And a groove is provided, and the other side is adapted to the remaining cross-sectional portion of the electrothermal heater element by plastic deformation, thereby achieving intimate contact between the lower base and the opposing surface of the upper base.

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