Tensile Testing of Insulating Thin Films Using Electrostatic Force Grip

Abstract

A new chucking system for tensile testing of insulating thin films using electrostatic force has been developed. The free end of a cantilever beam specimen has an electrode, which is fix to a probe on which a pair of electrodes is fabricated to apply the voltage. The system is applied to tensile testing of plasma CVD SiO₂ thin films. The tested part of the specimen is 0.65μm thick, 1-5μm wide and 30-300μm long. The mean tensile strength of the specimen is 1.6-2.3GPa depending on the specimen size. The strength is higher than that of the bulk materials. The fracture toughness of the film is 1.4-2.0MPa√m, which is calculated from the fracture strength of notched specimens.