| 摘要 |
PURPOSE:To equalize the film thickness of an epitaxial grow they layer constantly retaining the temperature in a reaction chamber within a range subject to minor difference even if the gas flow rate fluctuates by means of arranging a gas heater between a gas refining chamber and the reaction chamber. CONSTITUTION:A gas heater 2 is arranged between a gas refining chamber 1 and a reaction chamber 2. Besides, the gas heater 2 is composed of e.g. a glass pipe 4 to pass gas through and a resistor 5 wound around the periphery of pipe 4. Within a gas refining chamber 1, hydrogen gas or nitrogen gas refined up to pure gas in oxygen concentration not exceeding 0.01 ppm is led into the glass pipe 4 of gas heater 2 at the flow rate of 1-3l/min simultaneously to be heated at the same temperature as that in the reaction chamber 3 previously through the intermediary of the resistor 5. Later, said gas is led into the reaction chamber 3 temperature-controlled at 500-1000 deg.C. Through these proceduree, even if the gas flow rate in the reaction chamber fluctuates, the temperature in the reaction chamber 3 can be retained constantly within the range of 0.1 deg.C.
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