JP2975927B1 - Plate heating device - Google Patents

Abstract

An object of the present invention is to make it possible to continuously heat a heating object (a) by using a second filament (9b) even in the event that a first filament (9a) is disconnected or a power supply circuit thereof fails. SOLUTION: The plate heating device has a heat-resistant heated object support member 1 having an airtight space formed therein and having a flat heating portion 2 on which a heated object a is placed, and the heating of the heated object support member 1. The filament 2 has a first filament 9a and a second filament 9b connected in parallel to the first filament 9a and the filament heating power source 10. And

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plate heating apparatus for heating a thin flat plate-like heating object such as a semiconductor wafer to a high temperature.
The present invention relates to a plate heating device capable of continuously heating a heated object such as a semiconductor wafer.

[0002]

BACKGROUND OF THE INVENTION At present, there are 200 semiconductor manufacturers.
The company is aiming for a mass production system for 12-inch wafers with a target of 0 years. The supply of silicon wafers has become almost uncertain, and now we are moving to semiconductor manufacturing technology using it, for example, development of manufacturing equipment and its evaluation. The technology that forms the basis of the process technology is a substrate heater, and (a) thermal uniformity, (b) cleanness, and (c) reliability are required.

Conventionally used plate heating means include electric resistance heating, induction heating and lamp heating.
Two measures have been used. From the viewpoint of (a) thermal uniformity, (b) cleanliness, and (c) reliability, the heating means that can cope with a 12-inch large area wafer has been developed with improved electric resistance heating and lamp heating. Is underway.

[0004]

In the conventional heating apparatus, heat is radiated from the peripheral portion of the heating object a, and the area around the heating object a is heated.
There is a problem that the temperature of the part tends to decrease . The present invention has been made in view of the problems of the conventional plate heating device, and
It is an object of the present invention to provide a plate heating device capable of heating uniformly .

[0005]

According to the present invention, in order to achieve the above object, the heating means for heating the heating section 2 on which the heating object a of the heating object support member 1 is placed is provided in addition to the first heating means. at least a second heating means arranged, distribution inside
The closer the heating means is placed, the closer to the heating section 2 the better the heat transfer
By doing so, it is possible to heat the heating object a uniformly.
It is something that can be done .

[0006] That is, the plate heating device according to the present invention comprises:
A flat plate heating apparatus for heating a thin flat heating object a from the back side thereof, comprising a heat-resistant heating object supporting member 1 having a flat heating section 2 on which the heating object a is placed, A heating unit for heating the heating unit 2, wherein the heating unit includes a first heating unit, and at least one or more other heating units connected in parallel to the first heating unit and a heating power supply. have a, a heating means disposed inside the other heating
Located closer to the heating unit 2 of the heated object support member 1 than the means
It is characterized by having done.

[0007] In such a plate heating device, it is arranged inside.
The closer the heating means is, the closer it is to the heating section 2 and the better the heat transfer
So that the heating object a can be uniformly heated.
Become like At least the heating section 2 of the heating object support member 1
Is good be made of silicon-impregnated silicon carbide
Good. Such a heating section 2 has a smaller heat capacity than molybdenum or the like, and has good thermal responsiveness during heating and cooling.

[0008] Further, the first heating means and the other heating means,
It is preferable to arrange them concentrically. When the heating unit 2 is heated by the heating means disposed inside, the temperature of the peripheral portion of the heating object a tends to decrease due to heat radiation from the peripheral portion of the heating object a placed thereon. Therefore, multiple heating means are concentric
And the heating means arranged on the inside
By bringing the heating unit 2 closer to the heating unit 2 than the heating means and improving the heat transfer, the heating object a can be uniformly heated.

[0009]

Embodiments of the present invention will now be described specifically and in detail with reference to the drawings.
1 and 2 show an example of a semiconductor manufacturing apparatus using a plate heating device according to the present invention. In FIG. 1, the depressurizing vessel is not shown, and only the stage 17 is shown. However, in practice, the depressurizing vessel is surrounded from both sides of the stage 17 over the stage. A cooling liquid passage 7 is formed in the wall of the stage portion 17.
Can be cooled.

On the stage 17, a heat-resistant heating object support member 1 having a flat heating section 2 on which a thin plate-like heating object such as a silicon wafer is placed is installed. The support member 1 has a space that is air-tightly separated from a space outside the support member 1. More specifically, the heating object support member 1 has a cylindrical shape whose upper surface is closed by the heating unit 2 and whose lower surface is open, and the flat upper surface of the heating unit 2 is a thin plate such as a silicon wafer. It is wider than a heated material. The lower edge portion of the heated object support member 1 is fixed to the upper surface of the stage section 7 by being applied thereto, and is hermetically sealed by a vacuum seal material 8.

The heating member support member 1 or at least the heating portion 2 is made of silicon-impregnated silicon carbide, ceramics such as alumina or silicon nitride. As will be described later, when heating a heated object by electron impact, if the heated object support member 1 is made of an insulator such as ceramic, a conductor film is formed on the inner surface of the heating portion 2 and this conductor film is formed. It is grounded via the stage 17.

An exhaust passage 4 is formed in the stage section 17, and a vacuum pump 5 connected to the exhaust passage 4
The space inside the heated object support member 1 is evacuated and evacuated. Further, the first and second filaments 9 as first and second heating means are provided inside the heated object support member 1.
a, 9b and the reflector 3 are installed.

The filaments 9a and 9b are provided behind the heating section 2 of the heating object support member 1, and the filaments 9a and 9b
A filament heating power supply 10 is connected to the a and 9b via an insulating seal terminal 16. Further, between the filaments 9a and 9b and the heating unit 2, a stage unit 1 is provided.
The acceleration voltage of the electron acceleration power supply 11 is applied via the heating member 7 and the heated object support member 1. The heating unit 2 is grounded via the heated object support member 1 and the stage unit 17 and is kept at a positive potential with respect to the filaments 9a.

Here, the filaments 9a and 9b are composed of a first circular filament 9a disposed below and near the periphery of the heating section 2 and a second filament concentrically disposed inside the first filament 9a. And the filament 9b. FIG. 1 shows these first and second filaments 9a, 9b.
FIG. 2 shows a plane arrangement of the first and second filaments 9a and 9b.

As shown in FIG. 1, the first filament 9
a is arranged on the lower surface of the heating unit 2, and the second filament 9b is arranged above the first filament 9a, that is, closer to the lower surface of the heating unit 2 than the first filament 9a. These first filament 9a and second filament 9b are connected in parallel to a filament heating power supply 10. However, the second filament 9b is connected to the filament heating power source 10 via the switch 13.

As shown in FIG. 2, the first filament 9
a is arranged circularly, and the second filament 9b is arranged circularly on a concentric circle having a smaller diameter than the first filament 9a. In FIG. 2, reference numerals 12a and 12b represent
The drawing terminal of the 1st filament 9a and the 2nd filament 9b is shown, and these are connected to the filament heating power supply 10 shown in FIG.

The reflector 3 is provided behind the filaments 9a and 9b with respect to the heating section 2 of the heating object supporting member 1. The reflector 3 is made of a metal having a high reflectance such as gold or silver or a metal having a high melting point such as molybdenum, and at least a surface of the heated object support member 1 facing the heating section 2 is a mirror surface. Reflects infrared light. The reflectors 3 can be multiplexed. On the flat upper surface of the heating section 2 of the heating object support member 1, a thin flat heating object such as a silicon wafer is placed.

In such a plate heating device, the internal space of the heated object support member 1 is depressurized to a vacuum. Next, an electric current is passed from the filament heating power supply 10 to the first filament 9a as the first heating means, and the first filament 9a is turned on.
The thermoelectrons are emitted from a, and collide with the heating section 2 of the heating object support member 1 by the acceleration voltage applied by the electron acceleration power supply 11. Due to the electron impact, the heating section 2 of the heating object support member 1 is heated, and the heating object placed on the upper surface of the heating section 2 is heated.

At this time, since the inside of the heated object support member 1 is a vacuum space, heat is not released from the heating section 2 of the heated object support member 1 to the back thereof by convection, but heat is not emitted by radiation. Only release occurs. The radiant heat radiated to the rear of the heating unit 2 is reflected by the reflector 3 toward the heating unit 2 of the heating object support member 1, so that the release of heat to the rear surface of the reflector 3 is prevented, and Heating can be performed efficiently. Thereby, the heating object can be heated to a high temperature in a short time.

Since the first filament 9a is arranged near the peripheral portion on the lower surface of the heating section 2, the heating section 2
Is heated, and the periphery of the heated object is heated. Since the peripheral portion of the heated object radiates heat to the surroundings and the temperature tends to decrease, by heating this peripheral portion to a high temperature, the entire heated object can be heated to a uniform temperature. In the state where the heating object is heated in this manner, for example, the stage unit 17
Process gas such as silane is introduced into a decompression vessel surrounding the substrate, a silicon thin film is deposited on the surface of the heated object, and semiconductor processing can be performed on the surface of the heated object.

Here, when the first filament 9a is broken and no thermoelectrons can be emitted, the switch 13 is closed and a current is supplied from the filament heating power supply 10 to the second filament 9b. This second filament 9b
Is disposed near the lower surface of the heating unit 2, so that a temperature drop in the peripheral portion of the heated object can be prevented. In the above-described example, the filaments 9a and 9b are composed of the two filaments of the first filament 9a and the second filament 9b, but the filaments may be three or more. Furthermore, it is not limited to heating means by electron impact,
Needless to say, the present invention can be similarly applied to other heating means such as electric resistance heating.

[0022]

As described above, according to the present invention, even if there is a disconnection of the first heating means or a failure of its power supply circuit, etc. It is possible to obtain a plate heating apparatus capable of heating a and preventing a production line for semiconductor wafers or the like from being stopped.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view showing an example of a plate heating apparatus and a plate processing apparatus using the same according to the present invention.

FIG. 2 is a cross-sectional plan view of the plate body heating device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 heated object support member 2 heated object support member heating section 3 reflector 9 a first filament 9 b second filament 10 filament heating power supply 11 electron acceleration power supply

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Claims (3)

(57) [Claims] In a flat plate heating apparatus for heating a thin flat plate-like heating object (a) from the back side thereof, a heat-resistant heating object support member having a flat heating section (2) on which the heating object (a) is placed. 1) and heating means for heating the heating portion (2) of the heated object support member (1).
First heating means, having at least one or more other heating means connected in parallel to the first heating means and the heating power source, among the first heating means and other heating means, the inside Wherein the heating means disposed at a position closer to the heating section (2) of the heated object support member (1) is disposed at a position closer to the heating section (2) than the other heating means. 2. At least one of said heated object support members (1)
The heating unit (2) is made of silicon carbide impregnated with silicon
Plate body heating apparatus according to claim 1, characterized in that. 3. The plate heating apparatus according to claim 1, wherein the first heating means and the other heating means are arranged concentrically.