Optical and compositional characterization of GaAs(Ti) thin films deposited by R.F. magnetron sputtering

摘要

GaAs thin films with Ti incorporated, to which we refer to as GaAs(Ti), have been deposited by R.F. sputtering on fused silica and c-GaAs substrates under different process conditions. The films were characterized by EPMA, XPS and XRD to study the composition and structural dependence on the deposition conditions, paying special attention on the Ti content of the films. The optical responses of the films were analyzed by spectrofotometric, PDS and FTIR measurements. The Ti content is in all the samples above 10~(20) atoms/cm~3, so we can consider them as GaAs films highly Ti doped. It has been observed that an evolution of the Ga/As atomic content in relation with the Ti incorporation, which together with the results obtained from XPS measurements, indicates a possible substitution of Ga by Ti atoms in the deposited films.