JPH02158123A - Heater - Google Patents

Abstract

PURPOSE:To realize miniaturization and weight reduction and manufacturing cost reduction and also to improve uniformity in heating by conducting a current through a conductive layer formed at the outside of a heat buffering box so as to heat a substance to be heated. CONSTITUTION:A heat buffering box 1 is made in container shape out of a substance which has characteristics excellent in heat conductivity and electric insulating property, for example, alumina, etc. Also, at the outside of this heat buffering box 1, a conductive layer 4 consisting of a film which is made by overlaying metal such as, for example, chrome, etc., by deposition, etc., is provided over almost the whole face, and this conductive layer 4 is connected with a power source 5. And, for example, a semiconductor wafer 3 on which photoresist is applied is provided on a stage 2 in the heat buffering box 1, and desired temperature is input to a temperature controller 7 and the temperature inside the heat buffering box 1 is made to the desired temperature and baking treatment is done for a specified time. At this time, joule heat which is generated in the conductive layer 4 by currents conduction is transmitted to the heat buffering box 1 which is excellent in heat conductivity, and the whole heat buffering box becomes almost uniform temperature. Accordingly, the semiconductor wafer 3 is heated uniformly from the circumference and baked uniformly.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to a heating device.

(Prior Art) In general, heating devices, such as those used in the heat treatment process in semiconductor manufacturing, have conventionally been used to uniformly heat substrates such as semiconductor wafers in order to uniformly process the substrates such as semiconductor wafers. Various efforts have been made to make this possible.

For example, U.S. Patent No. 3,838,751 proposes a heating device consisting of a thermal buffer box made of a material with high thermal conductivity and a number of heating lamps provided outside the thermal buffer box. . In other words, in this heating device, the object to be heated is placed inside a thermal buffer box, and the object to be heated is heated through the thermal buffer box using a large number of heating lamps. can be heated evenly from the surrounding area.

(Problem to be Solved by the Invention) However, in the conventional heating device described above, it is necessary to provide a large number of heating lamps on the outside of the thermal buffer box, which increases the size of the device and increases the manufacturing cost. There is a problem. Further, if the number of heating lamps is reduced in order to avoid such a problem, a problem arises in that a temperature gradient occurs between near and far from the heating lamps, resulting in poor heating uniformity.

The present invention has been made in response to such conventional circumstances, and it is possible to significantly reduce the size and weight of the device and reduce the manufacturing cost compared to the prior art, as well as to improve heating uniformity. The present invention aims to provide a heating device.

[Structure of the Invention] (Means for Solving the Problem) That is, the present invention provides an object to be heated within a thermal buffer box, and heats the object through the thermal buffer box by a heating means provided outside the thermal buffer box. In the heating device configured to heat the object to be heated, the heating device is characterized in that a conductive layer is formed on the outer surface of the thermal buffer box, and the object to be heated is heated by passing electricity through the conductive layer. shall be.

(Function) In the heating device of the present invention, a conductive layer formed by depositing a metal such as chromium on the outer surface of the thermal buffer box by a method such as vapor deposition is energized. The device is configured to heat an object to be heated.

Therefore, compared to a conventional heating device using a large number of heating lamps, the device can be made significantly smaller and lighter, and manufacturing costs can be reduced, and heating uniformity can be improved.

(Example) Hereinafter, an example in which the present invention is applied to a baking apparatus for baking a substrate such as a semiconductor wafer will be described with reference to the drawings.

The thermal buffer box 1 is formed into a container shape from a material having good thermal conductivity and excellent electrical insulation properties, such as alumina. It is configured to place and accommodate a semiconductor wafer 3. The thermal buffer box 1 is provided with an opening/closing mechanism (not shown) so that the semiconductor wafer 3 can be loaded and unloaded therein.

Further, as shown in FIG. 2, the outside of the thermal buffer box 1 is coated with a metal such as chromium, for example, by a method such as vapor deposition. 0
．． A conductive layer 4 made of a thin film of 1 to 100 μm, preferably 0.5 to 2 μm, is provided over almost the entire surface, and a power source 5 is connected to this conductive layer 4.

Further, for example, a temperature 81J constant sensor 6 made of a thermocouple or the like is provided at the lower part of the mounting table 2 in the thermal buffer box 1, and the temperature measurement signal of this temperature 1111J constant sensor 6 is transmitted from the power supply. 5 to a temperature controller 7 that adjusts the power supplied to the conductive layer 4 as a feedback signal for temperature control.

In this embodiment with the above configuration, a semiconductor wafer 3 coated with, for example, photoresist is provided on a mounting table 2 within a thermal buffer box 1. Then, input the desired temperature into the temperature controller 7,
The temperature inside the thermal buffer box 1 is set to a desired temperature, and baking treatment is performed for a predetermined period of time.

At this time, the Joule heat generated in the conductive layer 4 by energization is
The heat is transmitted to the thermal buffer box 1, which has good thermal conductivity, and the entire thermal buffer box 1 has a substantially uniform temperature. Therefore, the semiconductor wafer 3 is uniformly heated from the surrounding area and uniformly baked.

That is, in this embodiment, a metal such as chromium is placed on the outside of a thermal buffer box 1 formed into a container shape from a material such as alumina that has good thermal conductivity and excellent electrical insulation properties. For example, a conductive layer 4 made of a thin film is provided by depositing it by a method such as vapor deposition. It is configured to heat-treat. Therefore, it is not necessary to provide a large number of heating lamps around the thermal buffer box 1 as in the conventional case, and it is possible to significantly reduce the size and weight of the device and the manufacturing cost. Further, by forming the conductive layer 4 on almost the entire surface of the outside of the thermal buffer box 1, it is possible to improve heating uniformity.

In the above embodiment, an example was explained in which the conductive layer 4 was formed of chromium, but the present invention is not limited to such an embodiment. , metals such as iron, lead, alumel, beryllium, antimony, indium, chromel, cobalt, strontium, rhodium, palladium, magnesium, molybdenum, lithium, rubidium, and carbon-based substances such as carbon black and graphite. , alloys such as nichrome, stainless steel, bronze, and brass, polymer-based composite materials such as polymer-grafted carbon, and composite ceramic materials such as molybdenum silicide, which are electrically conductive and function as heating resistors, that is, heat sources when energized. Any material may be used, and it can be used optimally by selecting an appropriate material depending on the heat generation temperature.

Further, the method for forming the conductive layer 4 is not limited to vapor deposition, and methods such as CVD, sputtering, ion blasting, thermal spraying, and explosion spraying can be used depending on the material.

Furthermore, the material for the thermal buffer box 1 is one that has good thermal conductivity and excellent electrical insulation properties.
In addition to alumina, ceramics such as aluminum nitride, zirconia, silicon carbide, and diamond, as well as metal oxides such as quartz and rutile, and bricks such as high alumina bricks and carbon bricks are also suitable. Also, the third
As shown in the figure, a thermal buffer box 1a is formed of a conductive material, and an insulating layer 1 made of the above-mentioned material is formed on the outside of the thermal buffer box 1a.
b, and the conductive layer 4 may be formed on the outside of the insulating layer 1b. Further, as shown in FIG. 4, for example, a conductive layer 4a
It is also possible to form a plurality of layers and further arrange a plurality of temperature measurement sensors (not shown) in a distributed manner to enable distributed heating.

[Effects of the Invention] As described above, in the heating device of the present invention, it is possible to significantly reduce the size and weight of the device and reduce manufacturing costs compared to the conventional device, and it is also possible to improve heating uniformity. .

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of a heating device according to an embodiment of the present invention;
FIG. 2 is a sectional view showing a main part of the heating device shown in FIG. 1, and FIGS. 3 and 4 are sectional views showing main parts of a modification of the heating device shown in FIG. 1...Thermal buffer box, 2...Placement table, 3.
... Semiconductor wafer, 4 ... Conductive layer, 5.
...Power supply, 6...Temperature measurement sensor, 7
...Temperature controller.

Claims (1)

[Claims] (1) In a heating device configured to provide an object to be heated in a thermal buffer box and heat the object via the thermal buffer box by a heating means provided outside the thermal buffer box, A heating device characterized in that a conductive layer is formed on the outer surface of the thermal buffer box, and the object to be heated is heated by supplying electricity to the conductive layer.