Spectroscopic ellipsometry studies of reactively sputtered nitrogen-rich GaAsN films

摘要: Abstract Nitrogen-rich GaAsN thin films have been deposited at 500 °C by reactive rf sputtering of GaAs target in argon–nitrogen atmosphere. The arsenic content the was varied changing nitrogen percentage atmosphere and As/Ga ratio estimated X-ray fluorescence measurements. Spectroscopic ellipsometry measurements carried out on these measured ellispometric spectra were fitted with theoretical generated using suitable model sample structures. From best fit parameters dispersion model, band-gap values variation refractive index extinction coefficient as a function wavelength obtained for different percentages 12% to 100% atmosphere, which are hexagonal GaN, exhibit GaN-like optical properties, though effects due excess amorphous phase seen less than 40% nitrogen. 5% dominantly polycrystalline x N 1− (  ≈ 0.01 0.08) variations parameters, consistent their structure composition. arsenic-rich amorphous.