As a gas industry term, the gas used in the semiconductor industry is collectively called electronic gas. According to its category, it can be divided into three categories: pure gas, high purity gas, and semiconductor special material gas. Special material gases are mainly used in epitaxy, doping and etching processes; high-purity gases are mainly used as diluent and carrier gases. Electron gas is an important branch of specialty gases. Electronic gas can be divided into electronic grade, LSI (Large Scale Integrated Circuit) level, VLSI (Very Large Scale Integrated Circuit) level, and ULSI (Ultra Large Scale Integrated Circuit) level according to the purity level and application occasion.