EBIC investigation of α and β dislocations in GaAs

Electron beam induced current (EBIC) microscopy is applied for studying the recombination activity of α and β dislocations introduced by micro-indentation in n-type GaAs. Quantitative measurements of EBIC contrast profiles across several tens of single 60° dislocations reveal a distinct difference between the contrast values of the two dislocation types. The same difference observed in various crystals and at dislocations introduced at various temperatures provides evidence for the recombination activity associated with the core electron states of dislocations. From diffusion-length measurements in a dislocated region the reduced minority carrier lifetime at α dislocations of the order of 10−12 s is estimated.