Ruthenium and sulfide passivation of In/sub 0.53/Ga/sub 0.47/As

The effectiveness of chemical surface modification of In/sub 0.53/Ga/sub 0.47/As using Na/sub 2/S, (NH/sub 4/)/sub 2/S/sub x/ and RuCl/sub 3/ has been studied through X-ray photoelectron spectroscopy (XPS), spectral response and Schottky barrier height measurements. XPS studies have shown that modification steps caused removal of native oxides and formation of S or Ru bonds with surface atoms. The minority carrier diffusion length L/sub p/ thus increased from 1.65 to 1.89 /spl mu/m due to reduction of surface recombination velocity S/sub r/ from 9.5/spl times/10/sup 3/ to 2.4/spl times/10/sup 3/ cm.s/sup -1/. Increase in Schottky barrier height /spl phi//sub 3n/ from 0.26 to 0.58 eV due to (NH/sub 4/)/sub 2/S/sub x/ treatment and reduction in ideality factor also occurred.