Reactive sputter deposition: A quantitative analysis

Abstract

An analysis of the reactive d.c. sputter deposition of compound films (metal oxides and nitrides) is presented. It leads to a model describing the process in terms of three easily accessible parameters: the reactive gas flow rate G, the sputtering power W and the sputtering yield of the target. It is shown that, for typical sputtering conditions, the reactive gas partial pressure, a variable in previous models, is of secondary importance. The model establishes the ration W/G as a fundamental parameter of reactive sputtering and predicts accurately the magnitudes of W/G for the deposition of such diverse films as TiN and Cd 2SnO 4. Detailed measurements of the reactive sputtering of titanium and aluminium targets in the presence of nitrogen and oxygen are presented and it is shown that the usual hysteresis effects depend mainly on intrinsic material properties that are only weakly modified by varying process conditions.