Mechanical testing of free-standing thin films

An overview is given of methods for testing thin-film tensile specimens of either MEMS materials or surface coatings. MEMS specimens are deposited in a final shape and need only to be released for testing, while specimens of coating materials must be extracted. Very brief descriptions of the specimen designs, force application approaches, and strain measurements are given along with a limited number of references. Representative stress-strain curves for polysilicon, silicon nitride, silicon carbide, electroplated nickel and diffusion aluminide bond coating are presented. Results at high temperatures are presented for the latter two materials.