Gas supply device, gas supply method

Abstract

The invention provides a gas supply device and a gas supply method through which gas for gas phase growth can be easily set into the expected concentration with low cost. An operation part has following control programs, flow set value signals of mixed gas output from a gas phase growth device are at least adopted as the reference, the manner that the mass of raw material gas guided into the gas phase growth device becomes constant is adopted, the flow of mixed gas guided into the gas phase growth device is calculated according to the concentration of the mixed gas, the first operation resultis obtained, a first mass flow controller is controlled according to the first operation result, and after the first mass flow controller is controlled, the manner that the total flow of the mixed gasflow and the dilute gas flow becomes constant is adopted, the flow of the dilute gas is operated according to the first operation result, accordingly, the second operation result is obtained, and a second mass flow controller is controlled according to the second operation result.

Description

technical field [0001] The present invention relates to a gas supply device and a gas supply method for supplying a raw material gas obtained by vaporizing a liquid raw material as a reactive gas together with a dilution gas to a vapor phase growth apparatus. Background technique [0002] For example, in a vapor phase growth apparatus for forming a vapor phase growth film (epitaxial film) on a wafer, a vapor growth film is formed on a wafer or the like by introducing a source gas (reactive gas) and a dilution gas. As a source gas supplied to such a vapor phase growth apparatus, for example, dichlorosilane (SiH 2 Cl 2 ), trichlorosilane (SiHCl 3 ), tetrachlorosilane (SiCl 4 ) and other liquid raw materials vaporized gas. With the exception of dichlorosilane, the above starting materials are liquids at room temperature and atmospheric pressure. [0003] Conventionally, a source gas and a carrier gas are mixed and supplied to a vapor phase growth apparatus as a mixed gas. ...

AI Technical Summary

Problems solved by technology

However, if the concentration of the gas actually used changes, the conversion factor will also change, so even if the set value is the same, the actual flow rate will change

Therefore, there is a problem that the operation of setting the reaction conditions at the time of changing the gas cylinder when the concentration of the mixed gas changes greatly becomes complicated.

Images