An improved shear lag analysis was used to calculate the longitudinal stress distribution in heterostructures with island layers. It was assumed that each layer consisted of many imaginary thin layers, in order to calculate the internal stress distributions over the entire heterostructure. The method was applied to the calculation of stresses in a GaAs/Si heterostructure whose GaAs layer was grown in various ways in order to determine the effect of island layers upon stress concentration at the island edge, and upon the reduction of stress in the GaAs layer. In the case of the stress distribution in the Si layer close to the hetero-interface, a sharp and large peak of tensile stress appeared at the edge of the GaAs island layer with misfit dislocations. This stress distribution agreed with the experimental value which was determined by Raman scattering. It was concluded that the tensile stress in a GaAs layer with misfit dislocations could be reduced by decreasing the length of the GaAs island layer.

K.Nakajima, K.Kitahara, S.Ochiai: Japanese Journal of Applied Physics, 1996, 35[1-5A], 2605-13