Physical Vapor Deposition Techniques I: Evaporation and Sputtering

Abstract

Thin films of numerous materials can be deposited on various substrates at low temperatures via condensation of vapors generated by vacuum evaporation or cathode sputtering techniques. Thermodynamic and kinetics aspects together with other basic considerations involved in evaporative deposition techniques are discussed. Evaporation of compounds and alloys can be improved using activated reactive evaporation processes. The major experimental techniques employed in vacuum evaporation and sputtering processes of some elements or compounds are described. The principles and basic equipment of diode sputtering are briefly presented. The sputtering yield of materials can be determined from the Sigmund model. The yield value depends on various factors : ion energy, incidence angle of ions, crystallographic orientation of the target surface,... The characteristics of sputtered species are compared to those of evaporated species. Thorough investigations of experimental parameter effects on sputter-deposition processes are required for optimization of deposition rates and properties of films. Sputtering systems operating at low pressures and high frequency sputtering equipments for deposition of insulating films are also described.