Reactant gases header
Reactant gases include ammonia, nitrous oxide, hydrogen chloride and tungsten hexafluoride.
Ammonia is typically used with either silane or dichlorosilane to produce silicon nitride layers in chemical vapour deposition. Silicon nitride films are used as passivation layers or interlayer dielectrics in semiconductor devices.
Nitrous oxide is used as an oxygen source in silicon oxide films formed in chemical vapour deposition processes. Nitrous oxide, available as a liquefied gas, is a strong oxidizing agent at temperatures greater than 300°C. Nitrous oxide also is used in photoresist stripping processes.
Hydrogen chloride is used to polish and etch wafers before deposition. Hydrogen chloride removes wafer surface defects caused by mechanical polishing and handling. It is also used with small amounts of oxygen to react with ("getter") metallic impurities potentially detrimental to metal oxide semiconductor (MOS) processes.
Tungsten hexafluoride is a colorless, non-flammable, corrosive liquid used as a CVD source of tungsten, or combined with silane.