ABSTRACT
Physical vapor deposition is a process in which the target material is first vaporized or sputtering then condensed on the substrate surface. Oxides with lower phosphorus concentrations will soften and flow, but higher phosphorus concentrations can give rise to deleterious effects for phosphorus can react with atmospheric moisture to form phosphoric acid which can consequently corrode the aluminum metallization. Aluminum has dominated metallization application since beginning of the semiconductor industry, In 1960s and 1970s, pure aluminum or aluminum siliconalloy were used as metal interconnection materials. Polysilicon film is employed in the form of metallization used for gate and interconnection of MOS devices. Sputtering, unlike evaporation, is very well controlled and generally applicable to all materials such as metals, insulators, semiconductors, and alloys film deposition in microelectronic fabrication. It has a better step coverage than evaporation induces far less radiation damage than electron beam evaporation and is much better at producing layers of compound materials and alloys.
