High-resolution imaging techniques were used to study  = 1 and  = 3 NiSi2/Si interfaces. Possible structural models for these interfaces could be completely deduced from dichromatic constrained coincidence site lattice patterns. In the case of the  = 1 NiSi2(001)/(001)Si interface, new interface structures were found, and a 2 x 1 reconstructed interface structure which involved a difference in composition was also observed. The new interface structures were confirmed by a through-focal series of high-resolution images from 2 orthogonal <110> beam directions. Domain-related interface structures which coexisted in  = 1 NiSi2 (001)/(001)Si interfaces were found to be separated by a ¼<111>-type dislocation which was associated with a demi-step. Only one interface structure was observed in both  = 1 and  = 3 NiSi2 (¯11¯1)/(¯111)Si interfaces, where the interfacial Ni atoms were deduced to be 7-fold coordinated. Two DSC dislocations, associated with steps, were identified in a  = 3 NiSi2 (¯11¯1)/(¯111)Si interface. The Burgers vectors of the DSC dislocations were deduced to be (1/12)[¯112]Si and (1/3)[¯111]Si. Both DSC dislocations were associated with a complete step, and the vector was ½[1¯10]Si. The long-period boundaries of  = 3 NiSi2 (¯111)/(1¯15)Si and NiSi2 (2¯21)/(001)Si were shown to decompose into short periods of symmetrical NiSi2 (¯11¯1)/(¯111)Si and NiSi2 (¯112)/(1¯12)Si atomic facets which resembled the asymmetrical tilt grain boundary case. The coexistence of 2 domain-related atomic faceting interfaces in the  = 3 NiSi2 (¯111)/(1¯15)Si and NiSi2 (2¯21)/(001)Si was also observed in various areas of an interface. They were separated by a ¼<111>-type dislocation which was associated with a demi-step. The Burgers vector and step of the dislocation which was required in order to separate 2 domain structures, and that of DSC dislocations in the  = 3 NiSi2/Si interface could be deduced by considering the CCSL model.

W.J.Chen, F.R.Chen: Philosophical Magazine A, 1993, 68[3], 605-30