Surface degradation of InxGa1-xN thin films by sputter-anneal processing: A scanning photoemission microscope study

In English The effects of nitrogen ion sputtering and thermal anneal processing on the surface electronic structure of the ternary III-V semiconductor In0.12Ga0.88N have been studied using scanning photoemission microscopy. No phase separation of the material is observed for annealing temperatures up to 650degreesC. However, samples annealed at 700degreesC for 5 h show clear evidence of phase separation. Furthermore, annealing at these temperatures with the sample surface directly exposed to ultrahigh vacuum produces a surface greatly deficient in In and with considerable surface roughness. This can be circumvented by using a sacrificial sample in physical contact with the film to artificially increase the local vapor pressure of Ga, In, and N during annealing. (C) 2003 American Institute of Physics.