Low-pressure CVD and Plasma- Enhanced CVD

LPCVD is a process used in the manufacturing of the deposition of thin films on semiconductors usually ranging from a few nanometers to many micrometers. LPCVD is used to deposit a wide range of possible film compositions with good conformal step coverage. These films include a variety of materials including polysilicon for gate contacts, thick oxides used for isolation, doped oxides for global planarization, nitrides and other dielectrics. LPCVD is similar to other types of CVD in that it is a process where a gaseous species reacts on a solid surface or wafer and the reaction that occurs produces a solid phase material. Each and every CVD process has the same four steps that must happen. First, the reacting gaseous species must be transported to the surface. Second, the gaseous species must absorb into the surface of the wafer. Third, the heterogeneous surface reaction produces reaction products.[1] Finally the gaseous reactants need to be removed from the surface.