Title screen

[References: p. 752 (9 tit.)]

The morphology of fractures in InGaN/GaN heterostructures on sapphire substrates under mul tipulse irradiation by a highcurrent electron beam is experimentally investigated. It is established that exci tation of samples by an electron beam with the threshold density from the heterostructure side leads to the formation of microfractures the number, size, and shape of which change during irradiation and are deter mined by individual properties of investigated samples. In heterostructures with stimulated luminescence, at the instant of the excitation pulse, bright microregions were detected against a background of homogeneous cathodoluminescence. The spatial positions of these microregions coincide with those of residual microfrac tures. Possible mechanisms of the electronbeaminitiated fracture of lightemitting heterostructures are analyzed.