MEASUREMENT OF RESIDUAL-STRESS IN MGO THIN-FILMS ON GAAS BY ELECTRON-MICROSCOPY

The residual stress in thin films of MgO deposited on GaAs is determined from the shape of characteristic diffraction bend contours, seen in the transmission electron microscope, in regions where the substrate was preferentially etched away leaving only the film. The residual stress in a MgO film deposited, by electron beam evaporation, at 450-degrees-C, was found to be compressive with a magnitude of 176 +/- 8 MPa. This is opposite in sign to that expected on the basis of the thermal expansion and lattice mismatches.