New UHV dilatometer for precise measurement of internal stresses in thin binaryhyphen;alloy films from 20 to 750 K

摘要

We describe a new dilatometric device for internal stress measurements of thin binaryhyphen;alloy films, able to operate in ultrahigh vacuum in the temperature range 20ndash;750 K. Using a threehyphen;terminal capacitor method, the displacement of the free end of a thin cantilever substrate is monitored by the capacitance change. With a sensitivity of 1 nm for substrate displacements, the resolution for stress detection is 105Pa in a 100hyphen;nmhyphen;thick film. Simultaneously with the stress measurement, the electrical resistivity of the film can be determined on the same substrate. The direct comparison of electrical and mechanical thinhyphen;film properties gives the ability to obtain additional information on the growth process and on the thinhyphen;film structure. Measurements of a crystalline Cu film and an amorphous Zr20Co80alloy film are shown.