JPS5973493A - Heating of substrate - Google Patents

Abstract

PURPOSE:To form a grown film having uniform thickness, uniform impurity concentration, and high quality, on a substrate, by furnishing a mounting table with a space to allow the flow of gas, and heating the substrate mounted on the table at a definite temperature by the gas heated with a heater. CONSTITUTION:An inert gas such as N2 gas is introduced through the gas inlet 25 into the gas flowing space 22, and heated with the heater 23. The flow of the gas and the voltage imposed to the heater 23 are controlled by the temperature sensor 24 to heat the N2 gas at a definite temperature. The mounting table is heated uniformly to a definite temperature, and accordingly, the substrate 4 mounted on the table 21 is also heated uniformly to the temperature. Since the heater 23 is kept in N2 gas, its exhaustion can be suppressed, and accordingly, the heating is stabilized and the life of the apparatus is elongated.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention relates to a method for heating a substrate, and more particularly to a method for heating a substrate on a mounting table of a chemical vapor deposition apparatus or a double etching apparatus.

(1)) Prior Art and Problems A conventional method of heating a substrate on a mounting table of, for example, a chemical vapor deposition apparatus (CVD apparatus) will be explained with reference to FIG. FIG. 1 is a schematic configuration diagram of a conventional CVD apparatus, in which a reaction chamber 8 surrounded by a chamber 2 is configured on a bottom plate A. Inside the reaction chamber 3, there is a mounting table 6 on which a substrate 4 is placed, and a reaction gas A jet nozzle μ/6 is provided, a heater 7 is attached to the mounting table 5, and an exhaust hole 8 is provided at the bottom.

As the heating heater 7, a rod heater or a spiral-wound carbon heater is usually used to heat the substrate on the mounting table to a predetermined temperature. As is well known, chemical vapor deposition utilizes a thermal chemical reaction, and is characterized by the uniformity of the temperature distribution on the surface of the mounting table, which is heated by placing the substrate on it, and the reaction gas introduced into the reaction chamber from the nozzle /I/6. By maintaining the suitability of the reactant gas supply, the thickness of the grown film on the substrate 4 can be made uniform.

However, in the above-mentioned heating method using a rod heater or spiral-wound carbon heater, there is a problem that local temperature differences occur on the substrate due to local heating of the heater, resulting in a lack of overall uniformity. Due to the wear and tear of the heater, uneven heat is generated on the surface of the mounting table, resulting in uneven temperature on the surface of the mounting table. had the problem of causing variations in impurity concentration.

(C) Purpose of the Invention The purpose of the present invention is to solve such problems, and by using high-temperature gas, the mounting table can be uniformly heated, and the growth film formed on the substrate can have a uniform thickness and an impurity concentration. An object of the present invention is to provide a method for heating a substrate that can form a good film quality with little variation.

((1) Structure of the invention, that is, the present invention is a method of placing a substrate on a mounting table and heating the substrate, in which a gas circulation space is provided in the mounting table, and gas heated by a heater is used to heat the substrate. , characterized in that the substrate is heated to a predetermined temperature.

(e) Embodiments of the Invention Below, embodiments of the present invention will be described with reference to the drawings. FIG. 2 is a sectional view of a main part of an embodiment of the present invention. In the figure, the mounting table 21 is the gas distribution space 22.
A plurality of heaters 28 are provided in the gas circulation space 22 to heat the circulating gas. Further, as shown in the figure, a temperature sensor 24 is attached at a predetermined position within the gas circulation space 22. When heating the mounting table 21 having such a structure, an inert gas such as nitrogen gas is introduced into the gas circulation space 22 through the gas introduction hole 25, and the nitrogen gas is heated by the heater 23 to adjust the gas flow rate and the heater. 28
The applied voltage is controlled to a predetermined temperature by the temperature sensor 24. That is, this is a method of heating the substrate 4 on the mounting table 24 to a predetermined temperature by uniformly heating the mounting table 21 to a predetermined temperature using a predetermined high-temperature gas circulation atmosphere. In this way, non-uniformity in temperature distribution due to local heating of the heater in the conventional method is improved, and since the heater 23 is kept in an inert gas atmosphere, i.e., nitrogen gas, the heater 28 is This method has the advantages of less consumption than conventional methods, a stable heating method, and a longer valve stand. FIG. 3 shows another embodiment of the present invention, in which the mounting table 8J is a gas distribution system in which high-temperature gas heated by heaters 33 provided in advance in a plurality of gas introduction pipes 32 is laminated multiple times as shown in the figure. This is a method in which the temperature is controlled in the same manner as described above by flowing through the space 34 and by the temperature sensor 85 installed at a predetermined position within the circulation space 84, thereby obtaining uniformity of the temperature distribution on the mounting table 31.

In this way, the substrate 4 on the mounting table 31 can be heated uniformly by the high-temperature gas surrounding air and by the temperature insulation effect by lamination.
It is possible to uniformly heat the heater 33 to a desired temperature, and as described above, it is also possible to prevent the heater 33 from being worn out.

In FIGS. 2 and 8, parts that are the same as those in the previous section are designated by the same reference numerals.

(n) As described in detail of the invention, according to this embodiment, the substrate on the mounting table can be uniformly heated by using high-temperature gas as a heating source, and the substrate can be grown uniformly and favorably by the CVD method. It is possible to form a film, and at the same time, it is possible to extend the life of the device.Also, it is possible to use the heating method of the present invention in a dry etching device, and this example is considered as an example of the present invention. This mention of a phase growth apparatus is not intended to limit the scope of the present invention.

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram of a conventional CVp device, Fig. 2 is a sectional view of a main part to explain one embodiment of the present invention, and Fig. 8 is a sectional view of a main part to explain another embodiment. It is. In the figure, 4 is the board, 21 and 31 are the mounting tables, and 23 and 33
is a heater, and 22 and 34 are gas circulation spaces. Figure 1 Figure 2 Figure 1゜Figure 3

Claims (1)

[Claims] A method of placing a substrate on a mounting table and heating the substrate, wherein the mounting table is provided with a gas circulation space, and the substrate is heated to a predetermined temperature by gas heated by a heater. A method for heating a substrate, characterized by: