Observation of Crystal Lattice Planes in Neutron and Ion Bombarded Ge Invited Paper

In the present work a review of the acheivements of the Gossick and Crawford model of disordered regions in semiconductors is given, together with a transmission electron microscope investigation of the structural characteristics of the disordered regions themselves. Both diffraction contrast and phase contrast electron microscope images have been used to examine disordered regions observed in Ge irradiated with fast neutrons or 100 keV oxygen ions. Experimental evidence is presented which clearly demonstrates that the disordered regions have an amorphous rather than a defect rich crystalline structure. Furthermore, each disordered region is observed to be surrounded by a non-uniform strain field extending out to ~65Å from the disordered region center.