Control of stress in metal films by controlling the temperature during film deposition

摘要

Materials such as titanium are vapor-deposited to form a film on a substrate while the substrate is thermally coupled to a temperature-controlling thermal source. Varying the temperature conditions of the substrate when the film is deposited varies the intrinsic stress of the film, which varies the change in substrate shape caused by the presence of the film. A film having a desired intrinsic stress may be obtained by control of the substrate temperature when the film is deposited. A stress-controlled titanium film may be used, for example, as an adhesion layer between a silicon movable structure in an optical MEMS device and a gold layer serving as a reflecting surface.