To perform hot isotropic pressure treatment in a short cycle by providing a means to couple together a high pressure vessel and a pressure accumulator in such a manner to switch the vessel and the accumulator into series and parallelism on the outlet side of a compressor to pressurize pressure medium gas.
A means to couple together a high pressure vessel 1 and a pressure accumulator 4 in such a manner to switch the vessel and the accumulator into series and parallelism is arranged on the outlet side of a compressor 3 to pressurize pressure medium gas. By driving a gas compressor 3 to pressurize pressure medium gas, the high pressure accumulator 4 is filled with the pressure refrigerant gas through pressurization up to, for example, the maximum delivery pressure of the gas pressure. A silicon wafer being a product to be treated is charged in the high pressure vessel 1 for process treatment. After the opening part of the high pressure vessel 1 is closed, valves 10 and 16 are opened. The high pressure vessel 1 for process treatment is filled with high pressure gas from the high pressure accumulator 4 by utilizing a differential pressure. When the value of a pressure gauge 21 attains a given pressure (a treatment pressure), the valve 16 is opened.
ISHII TAKAHIKO
NAKAI TOMOMITSU
SAKASHITA YOSHIHIKO
ULVAC CORP