STRAIN ANALYSIS FO GAINAS/GAAS STRUCTURES USING TEM IMAGE SIMULATION OF 90-DEGREES-WEDGES

A new characterisation technique for the analysis of strain is presented. The method matches TEM images of thickness fringes from 90-degrees-cleaved wedge samples with simulated TEM images obtained from theoretical calculations of the strain relaxation at the edge of the wedge. The technique is applied here to a GaInAs/GaAs strained single quantum well structure. The remarkable sensitivity of the thickness fringe contrast to the misfit strain, f, and the deviation parameter, s, is demonstrated.