JPS63124424A - Heating method for sample - Google Patents

Abstract

PURPOSE:To realize a desired change in temperature with time exactly and rapidly, by controlling the pressure of a gas in a gap between a heating body and a substance to be heated so as to control the degree of heat conduction in the gap when heating a sample. CONSTITUTION:On the occasion of heating a sample 4, the sample 4 set on supporting studs 3 is heated while gas pressure control means 13 such as valves are controlled to control the internal pressure of a heating apparatus, and thereby the temperature of the sample 4 is changed with time in a desired manner. By this method, thermal conductivity based on conduction and convection can be controlled easily and rapidly, and thus the sample 4 can be heated with the temperature thereof changed with time exactly and rapidly without wasting any time.

Description

[Detailed Description of the Invention] [Summary] This is an improvement in a heating method for semiconductor wafers, etc. (hereinafter referred to as samples).

In order to heat the sample while controlling the temperature over time, a heating device is used in which the heating element and the sample to be heated are not in complete contact with each other, leaving some gap,
This is a method of heating a sample while changing the temperature over time with high responsiveness without wasting time by controlling the air pressure inside the heating device and controlling the thermal conductivity in the gap.

[Industrial application field]

The present invention relates to improvements in methods for heating samples. In particular, it is a method of heating a sample while changing the temperature over time with high responsiveness without wasting time.

[Conventional technology]

Conventionally, heating devices such as hot plates, ovens, and furnaces have been used to heat semiconductor wafers, etc. (hereinafter referred to as samples) for purposes such as heat treatment, baking, and ashing. An example of a heating device will be described with reference to the drawings.

Referring to FIG. 2, reference numeral 1 denotes a vacuum container, which has an air supply pipe 11 and an exhaust pipe 12. 2 is a heating element, which is provided on the wall of the vacuum container l. Reference numeral 3 denotes a sample support stand that supports a sample 4 such as a semiconductor wafer.

There are various types of heating elements, including those that use electrical resistance.
In any case, it generally has only a heating function and no cooling function, and since its own heat capacity is large, the rate of temperature decrease is small compared to the rate of temperature increase. Moreover, it is not always easy to control the amount of heat generated due to structural constraints and the like, and the amount of heat generated is generally constant.

[Problem that the invention seeks to solve]

When heating a sample such as a semiconductor wafer, it is often necessary to temporally control the heating temperature as shown in FIG. However, as mentioned above, the heating element of the sample heating device is
It does not have a cooling function, the amount of heat generated is constant, and the O
Since it only has an N/OFF function, it is difficult to accurately change the temperature over time with high response and no wasted time.

The purpose of the present invention is to eliminate this drawback, and to provide a method for accurately and quickly heating a sample such as a semiconductor wafer while changing the temperature over time without wasting time. be.

[Means for solving problems]

The means taken by the present invention to achieve the above object is based on the internal pressure of a sample heating device in which a heating element and a sample such as a semiconductor wafer are not in complete contact with each other, leaving a gap between them. The goal is to heat the sample while controlling the thermal conductivity within this gap.

[Effect]

Heat conduction methods include conduction, dielectric, and radiation methods, but in the sample heating method according to the present invention, the pressure of the gas in the gap between the heating element and the heated object is controlled. As a result, thermal conductivity based on conduction and convection can be controlled easily and quickly, and the temperature of samples such as semiconductor wafers can be heated accurately and quickly while changing the temperature over time without wasting time. be able to.

〔Example〕

Hereinafter, a method for heating a sample according to an embodiment of the present invention will be further described with reference to the drawings.

Referring to FIG. 1, there is shown a configuration diagram of a heating device used to carry out a method for heating a sample according to an embodiment of the present invention.

In the figure, reference numeral 1 denotes a vacuum container, which has an air supply pipe 11 and an exhaust pipe 12, and the air supply pipe 11 and the exhaust pipe 12 are provided with an air pressure control means 13 such as a valve. 2 is a heating element;
It is provided on the wall of the vacuum container 1.

Reference numeral 3 denotes a sample support stand that supports a sample 4 such as a semiconductor wafer, and the sample 4 such as a semiconductor wafer and the heating element 2 are not in close contact with each other, and are at least 1100p.

The above gap is made to remain.

To heat the sample 4 such as a semiconductor wafer, the sample 4 such as a semiconductor wafer is placed on the support stand 3, the valve isobaric pressure control means 13 is controlled to control the internal pressure of the heating device, and the semiconductor wafer is heated. The temperature of the sample 4 is changed over time as desired.

The temperature of the heating element 2 was maintained at 300°C, and the gap between the heating element 2 and the sample 4 such as a semiconductor wafer was set to 300 p, vn.
Fig. 4 shows the results of an experiment conducted by maintaining the internal pressure at 0.5 to I Torr. As is clear from the figure, in the case of I Tart, the temperature changes by 300°C in 15 seconds, but in the case of Q, 5 Torr, it takes 3 minutes to make the same temperature change, and the gap size and temperature It has also been confirmed that there is a strong correlation with the time required for change.

〔Effect of the invention〕

As explained above, in the method for heating a sample according to the present invention, a heating device is used which has a means for controlling the internal pressure and supports the sample as an object to be heated at a distance from the heating element. Since the temperature of the sample, which is the object to be heated, is controlled over time, the desired temperature change over time can be achieved accurately and quickly without wasting time.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a heating device used to implement a sample heating method according to an embodiment of the present invention. FIG. 2 is a configuration diagram of a sample heating device according to the prior art. FIG. 3 is a graph showing the change in temperature required over time in the sample heating process. FIG. 4 is a graph showing experimental results for confirming the effect of the present invention. DESCRIPTION OF SYMBOLS 1... Vacuum container, 2... Heating element, 3... Sample support stand, 4 fists - Sample such as a semiconductor wafer to be heated, 11...
- Air supply pipe, 12... Exhaust pipe, 13... Internal pressure control means (valve).

Claims (1)

[Claims] It has a means (13) for controlling internal pressure and a heating element (2) on the wall surface.
) and a sample support stand (3) that supports the sample (4) at a distance from the heating element (2) in the vacuum vessel (1). Using a sample heating method, the thermal conductivity between the sample (4) and the heating element (2) is changed by controlling the internal pressure of the vacuum container over time, and the thermal conductivity of the sample (4) is changed. A method for heating a sample, characterized by controlling the temperature over time.