Amorphous gallium-arsenic-nitrogen (a-GaAsN) thin films were deposited by sputtering a crystalline GaAs target with different mixtures of argon and nitrogen. X-ray photoelectron spectroscopy (XPS) and x-ray excited Auger electron spectroscopy (XAES) were employed to study the Ga and As core levels and the corresponding LMM Auger transitions of films with different N concentrations. Chemical information of these samples was obtained through the analysis of the Auger parameter, which is exempt from problems inherent in the interpretation of XPS and XAES shifts, revealing aspects associated with the composition of the a-GaAsN films. In particular, these experimental results show the preferential bonding of N to Ga atoms in the formation of N-rich amorphous GaAsN films. (C) 2000 American Institute of Physics. [S0003-6951(00)02816-3].761622112213