FORMATION OF CYLINDRICAL N-P JUNCTION DIODES BY ARSENIC ENHANCED DIFFUSION ALONG INTERFACIAL MISFIT DISLOCATIONS IN P-TYPE EPITAXIAL SI SI(GE)/

Arsenic enhanced diffusion along individual misfit dislocations in Si/ Si(Ge) heterostructures has been detected and imaged using scanning el ectron microscopy (SEM) and in the electron beam induced current (EBIC ) mode. The formation of buried cylindrical, or conical, diodes surrou nding misfit dislocations has been observed. The diffusion enhancement is not uniform for each dislocation. EBIC/SEM micrographs reveal a da rk recombination contrast in the vicinity of the dislocation core and a white generation signal within the space-charge region of the surrou nding n/p diode. Based on an experimental isoconcentration etching pro file and a simple model for enhanced diffusion, the dislocation diffus ion coefficient for arsenic is estimated to be up to six orders of mag nitude higher than that in the host crystal.