Formation of ohmic contacts on semi-insulating GaAs by laser deposition of In

A method for producing ohmic contacts on semi-insulating GaAs by laser ablation with subsequent laser deposition of In is proposed. The contacts are formed at room temperature; thus, the high-temperature annealing used in other technologies is excluded. The ohmic properties of the contacts are retained in a range of currents that is several orders of magnitude wide, regardless of the direction of current. The electric potential is distributed linearly along the sample, and the current is limited only by the bulk resistivity of the material itself. The method is promising for the formation of high-precision arrays of ohmic contacts that penetrate the whole thickness of the sample in the fabrication of microelectronic devices.