JPH11204239A - Plate type heater, its manufacture and thin film manufacturing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plate type heater of excellent temperature uniformity in which gas storage or emission will not occur, and a manufacturing method and a thin film manufacturing device to manufacture high purity and uniform thin film. SOLUTION: A plate type heater in which a sheath heat generation body 22 incorporated in a heat conductive plate 21 comprising metal, and in which one surface is set as heating surface comprising the heat conductive plate 21, the sheath heat generation body 22 installed on a bottom of a heat generation body groove 21a formed on the other surface to be parallel to the heating surface, and metal filler 25 cast between the heat generation body groove 21a and the sheath heat generation body 22 without a gap, and this filler 25 is welded with the heat transfer plate 21 at a weld part 26. A thin film manufacturing device to form a thin film of metal or semiconductor by sputtering or plasma chemical vapor phase deposition is provided with the plate type heater.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plate type heater for heating a substrate in a vacuum when a film is formed on a substrate surface by sputtering or the like, for example, for manufacturing a thin film photoelectric conversion element. The present invention relates to a thin film manufacturing apparatus provided with:

[0002]

2. Description of the Related Art FIG. 3 is a schematic sectional view of a thin film manufacturing apparatus for forming a thin film by sputtering in a vacuum vessel using a conventional plate type heater. Such a thin-film manufacturing apparatus has a plate-type heater 2 for heating a substrate 1 in a vacuum in a vacuum vessel 3, and performs sputtering by discharging between a cathode 4 and an anode 5 (power supply is 6). The substance 3 is transferred to the substrate to form a thin film. The same plate type heater 2 is used also in the case of forming a thin film on a substrate by a plasma reaction by introducing a predetermined source gas from the outside, that is, in the case of plasma enhanced chemical vapor deposition (CVD).

[0003] These plate type heaters are required to have a high degree of cleanness, such as uniformity of the temperature on the surface of the heater, little degassing generated from the heater, and little occlusion of plasma reaction gas. FIG. 4 is a side view of a conventional plate type heater. Conventional plate-type heaters have a so-called sheath-type heater in which a heating element such as a nichrome wire is coated on the outer periphery with an insulator such as magnesium oxide, and is covered with a protective tube made of a heat-resistant material such as stainless steel or inconel to protect these elements. A body 22 is used. There is a heat transfer plate 21 whose outer periphery is formed of an aluminum casting or the like so as to incorporate the sheath type heating element 22. The heat transfer plate 21 has a function of uniformly dispersing the heat of the built-in heater and heating the substrate by contacting the substrate and the heating surface 21s. The area of the heat transfer plate is determined according to the heating area of the substrate, but according to the area of this heat transfer plate, the sheath-type heating element is bent to form a shape that will heat the heat transfer plate uniformly. Then, this is fixed in a mold, and aluminum or the like serving as a heat transfer plate is cast and formed.

[0004]

As a problem of the plate type heater using such a cast heat transfer plate, a minute space called a cavity is formed on the surface and inside of the heater. This is a phenomenon peculiar to the casting material. This space contains various gases when the material is melted, and is released from the surface of the heat transfer plate when heated in a vacuum. Also, machining oil during processing enters the nests on the surface, and cannot be removed even after washing after processing. This processing oil is also gasified and released by heating in vacuum. Obviously, these gases are harmful when forming the thin film. In a CVD (Chemical Vapor Deposition) apparatus or the like, the gas type is changed to form a plurality of layers of film. At this time, the gas used for the pretreatment is absorbed in the space of the heat transfer plate, and is used for the next treatment. It may be released, making it impossible to form a target film.

[0005] Another problem at the time of casting the heater is that when the molten metal (hot water) is poured into the mold, the sheath-type heating element is deformed by the molten metal, so that the initially formed shape is displaced and becomes parallel to the surface of the heat transfer plate. In other words, the difference in the surface temperature of the heat transfer plate is increased. This temperature difference between the heat transfer plates causes a non-uniform thin film to be formed in the thin film manufacturing apparatus.

SUMMARY OF THE INVENTION An object of the present invention is to provide a plate type heater having a heat transfer plate which is excellent in temperature uniformity, has no cavities inside and on the surface and does not occlude or release gas, and a method of manufacturing the same. An object of the present invention is to provide a thin film manufacturing method apparatus having a plate-type heater capable of manufacturing a thin film having a uniform purity.

[0007]

In order to achieve the above-mentioned object, in a plate type heater having a heat generating body made of metal and having a heat generating plate built in a metal and having one surface as a heating surface, the heat generating plate and the sheath heat generating element are connected to each other. The sheath heating element installed at the bottom of the heating element groove formed on the other surface in parallel with the heating surface, and filling of metal cast without gap between the heating element groove and the sheath heating element And the filler is welded to the heat transfer plate.

The heat transfer plate is preferably a rolled or forged metal plate. Preferably, the filler is aluminum. A sheath heating element is installed in a heating element groove formed in advance on the heat transfer plate, a molten metal is cast into the heating element groove, cooled and hardened to form a filler, and the filler is fixed to the heat transfer plate by welding. Item 4. The method of manufacturing a plate-type heater according to any one of Items 1 to 3, wherein in the step of casting the molten metal of the metal into the heat generating element groove of the heat transfer plate, the sheath heat generating element placed in the heat generating element groove of the heat transfer plate. It is advisable to energize and maintain a heated state.

When the filler is welded to the heat transfer plate, the sheath heating element is preferably energized and maintained in a heated state. A thin film manufacturing apparatus that forms a metal or semiconductor thin film on a substrate surface by sputtering or plasma enhanced chemical vapor deposition while holding a flexible substrate at a fixed distance in the vicinity of a plate type heater or holding in close contact and heating. The plate-type heater is referred to as the above-described plate-type heater.

[0010] According to the present invention, the sheath-type heating element is fixed to the heating surface of the heat transfer plate in parallel with the heating surface of the heat transfer plate without any gap by the metal filler having good heat conductivity. And the heat transfer plate can be expected to heat up quickly. Further, since the filler and the heating element groove are welded, the adhesion of the filler does not change even with the temperature cycle of the heat transfer plate, and the life of the heater plate can be expected to be long.

In addition, since the heat transfer plate is replaced with a cast material having many cavities, a rolled or forged metal plate having no cavities is used. It can be expected that the release of oil will be very small and that the production of semiconductor thin films in which the gas released in vacuum must not become an impurity will be easy. Since the volume of the heating element groove is small and the temperature of the heat transfer plate and the sheath-type heating element at the time of filling the filling material is high, the flow of the molten metal is good and the gaps and nests are small, and the filling material and the heating element groove are in close contact. The properties are improved, and the temperature rise, temperature uniformity and life are excellent.

Further, during welding, the sheath-type heating element is energized and heated to a high temperature, so that the usual burner heating or the like becomes unnecessary, and the welding operation is easy and can be performed by one person. Also, no burrs are formed in the welded portion.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIGS. 1A and 1B show a plate type heater according to the present invention, wherein FIG. 1A is a side view and FIG. 1B is a plan view. FIG. 2 is a sectional view taken along the line XX in FIG. 1 of the plate heater according to the present invention.

A heat transfer plate 21 made of a rolled aluminum plate is placed on a heat transfer plate 21 from a side opposite to a heater (heating) surface.
A heating element groove 21a for embedding the heater body 22 was formed. The heating element groove 21a is processed by milling or the like. From the viewpoint of heat uniformity and mechanical strength, the depth of the heating element groove 21a is preferably not more than の of the thickness of the heat transfer plate. When the sheath-type heating element 22 is placed at the bottom of the heating element groove 21a, the filling 25 formed by curing the poured molten metal completely covers the sheath-type heating element 22. Further, it was set to such an extent that a welded joint between the filler 25 and the heat transfer plate 21 could be formed. Heat transfer plate 2 due to thermal expansion difference
The filler and the welding material (welding rod) 26 are preferably made of the same material as the heat transfer plate 21 so that the heat transfer plate 1 is not deformed or warped. The filler and the welding material may be an aluminum alloy or a copper alloy.

Further, a thermocouple for controlling the temperature of the sheath-type heating element is held at the center of the heat transfer plate 21.
A tubular thermocouple port 23 such as a stainless steel tube was provided. A thermocouple is inserted into the tube up to the bottom of the heat transfer plate 21. At the end of the sheath heater, there is provided a vacuum sealing cap 24 made of stainless steel used when the sheath heater is attached to the thin film manufacturing apparatus main body.

The manufacturing process was as follows. First, using a rolled aluminum plate, a heating element groove was formed by milling according to a desired shape and thermal design of the heat transfer plate. The sheath type heating element was bent so as to match the heating element groove, and was placed at the bottom of the heating element groove. Next, when the molten metal flows into the sheath-type heating element placed in the heating element groove while being electrically heated, the molten metal flows to the surface of the sheath-type heating element and to the corners of the groove, and the adhesion to the heat transfer plate is better, and A plate type heater with good transmission can be obtained.

In this manner, the position of the sheath-type heating element is as designed, and the heat is uniformly transmitted to the heat transfer plate, so that the heater has no temperature difference. Further, the heater main body can be arbitrarily installed according to the shape of the heat transfer plate, and a heater having no temperature difference can be provided. Further, at the time of welding, the periphery of the welded portion can be heated to 350 ° C. or more by the electric heating of the sheath-type heating element, and the welding operation can be easily performed. Burner heating by other workers is not required, and cost can be reduced by one person. Example 2 The plate type heater manufactured in Example 1 was attached to a thin film manufacturing apparatus by sputtering (see FIG. 3), and a metal electrode layer was formed.
In addition, a thin film solar cell was manufactured using the thin film by attaching the film to a thin film manufacturing apparatus by plasma CVD and forming a photoelectric conversion layer of amorphous silicon.

As a result, as compared with the case where each thin film is manufactured by using the conventional cast plate type heater, variation in characteristics is reduced, and the production yield is improved.

[0019]

According to the present invention, there is provided a plate type heater in which a sheath heating element is built in a heat transfer plate made of metal and has a heating surface on one side.
A sheath heating element installed at the bottom of a heating element groove formed on another surface in parallel with the heating surface, and a metal filler cast without gap between the heating element groove and the sheath heating element Since the filler is welded to the heat transfer plate, the sheath-type heating element is fixed to the heat transfer plate in parallel with the heating surface of the heat transfer plate by a metal filler having good heat conduction without gaps. The uniformity of the temperature of the heating surface of the heat plate is increased, and the temperature of the heat transfer plate rises quickly. Further, since the filler and the heating element groove are welded, the adhesion of the filler does not change even with the temperature cycle of the heat transfer plate, and the life of the heater type plate is long.

In addition, since the heat transfer plate is replaced with a cast material having many cavities, a rolled or forged metal plate without cavities is used. The release of oil is very low, and the contamination of the semiconductor thin film and the like is eliminated, and the present invention can be applied to the production of a high-purity semiconductor thin film. In addition, since the casting operation and the welding operation are performed while the sheath-type heating element is energized and heated, no burrs are formed in the welded portion, so that the usual burner heating is not required, and the welding operation is easy and can be performed alone. It also reduces costs.

Further, the thin film manufacturing apparatus provided with the plate type heater according to the present invention has features such as temperature uniformity, non-contamination of the thin film and long life, and is particularly suitable for manufacturing a thin film photoelectric conversion element. I have.

[Brief description of the drawings]

FIG. 1 shows a plate-type heater according to the present invention, wherein (a)
Is a side view, and (b) is a plan view.

FIG. 2 shows the plate heater according to the present invention in FIG.
X sectional view

FIG. 3 is a schematic cross-sectional view of a thin-film manufacturing apparatus for forming a thin film by sputtering in a vacuum vessel using a conventional plate-type heater.

FIG. 4 is a side view of a conventional plate heater.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Plate type heater 21 Heat transfer plate 21a Heating element groove 21s Heating surface 22 Sheath type heating element 23 Thermocouple port 24 Vacuum sealing cap 25 Filler 26 Welded part

Claims (6)

[Claims] 1. A plate-type heater having a heat-generating body built in a heat-transfer plate made of metal and having one surface as a heating surface, wherein the heat-transfer plate is formed on another surface in parallel with the heating surface. The heating element provided at the bottom of the heating element groove, and a metal filler cast without any gap between the heating element groove and the sheath heating element. A plate type heater characterized by being welded to a plate. 2. The plate-type heater according to claim 1, wherein said heat transfer plate is a rolled or forged metal plate. 3. The plate heater according to claim 1, wherein said filler is aluminum. 4. A sheath heating element is installed in a heating element groove formed in advance on the heat transfer plate, and a molten metal is cast into the heating element groove, cooled and hardened to form a filler, and the filler is welded to the heat transfer plate. 4. The method of manufacturing a plate-type heater according to claim 1, wherein the step of casting the molten metal of the metal into the heating element groove of the heat transfer plate comprises placing the molten metal in the heating element groove of the heat transfer plate. A method of manufacturing a plate-type heater, comprising supplying a current to a heated sheath heating element to maintain the heated state. 5. A method for manufacturing a plate-type heater, wherein a current is supplied to a sheath heating element to maintain a heated state when the filler is welded to a heat transfer plate. 6. A thin film manufacturing apparatus for forming a metal or semiconductor thin film on a substrate surface by sputtering or plasma chemical vapor deposition while heating a flexible substrate in the vicinity of or in close contact with a plate type heater. 4. The thin film manufacturing apparatus according to claim 1, wherein the plate heater is the plate heater according to claim 1.