The in situ measurement of the intrinsic stresses in nanofilms

Abstract

A method for the in situ measurement of intrinsic stresses in nanofilms is described. It is based on measuring the cantilever beam deflection during the vacuum deposition of thin films. Magnetron sputter deposition is used in this work. In order to determine the cantilever beam deflection, the capacity of a capacitor composed of a stationary plate fixed on a stand and a plate fixed on the free end of the specimen was measured. A condenser was inserted into the multivibrator circuit to measure the small condenser capacity. The in situ stress measurements for nanofilms of TI and Cu sputtered on Cu substrates were performed. The stresses that occurred in the TI film were found to be tensile, but stresses that occurred in the Cu film were compressive; the stress magnitude significantly changes when letting air into the vacuum chamber. The results show the perspective usage of this method for in situ stress measuring, as well as for a study of the effects of the interaction between gas and nanostructured films.