X-ray photoelectron spectroscopic investigation of the GaAs nitridation mechanism with an ECR plasma source

The mechanism of arsenic replacement by nitrogen to produce beta-GaN in GaAs(001) samples exposed to the flux of an electron cyclotron resonance (ECR) plasma source is discussed on the basis of core level photoemission and photodiffraction data collected in situ. An amorphisation step is clearly evidenced which could favour nitrogen incorporation but should be kept at a minimum in order to maintain a cubic crystallographic template to stabilize-the Ga-N bonds into epitaxial beta-GaN.