Pulsed ruby laser diffusion of tin into GaAs

Spin-on tin silica films deposited on semi-insulating undoped GaAs were irradiated by a ruby laser at various incident energies. The resulting tin diffused layers, characterised by Hall effect measurements, show the formation of an n+ layer. The surfaces of the tin doped layers were observed in a scanning electron microscope and analysed in an electron microprobe. The concentration of tin in laser diffused and thermally diffused layers was compared by Rutherford backscattering measurements. Typical FET contact structures show higher breakdown voltages for laser diffused layers than for thermally diffused layers.