Nonalloyed ohmic contacts to n-type GaAs by pulsed ruby laser diffused tin from tin-silica film

Nonalloyed ohmic contacts were formed on n
⁺
diffused layers on GaAs. The n
⁺
layers were formed on semi-insulating substrates by depositing a layer of tin-silica film and irradiating by ruby laser alone without thermal diffusion. Vacuum-evaporated AuGe-Ni contacts display low specific contact resistance ≃1.8 × 10
^-6
Ω.cm
²
, without alloying.