Characterization of Pulsed Laser Beam Mixed AuTe/GaAs Ohmic Contacts

ABSTRACTThe formation of pulsed laser processed AuTe/n—GaAs ohmic contacts was investigated using I—V measurements, Rutherford Backscattering, and Mössbauer spectroscopy. Ohmic contact resistances comparable to those of furnace processed AuTe and AuGe/GaAs contacts were measured; however, a much thinner intermixed layer was obtained by the laser processing. No evidence for the formation of a n++—GaAs layer could be derived from the experimental data. The results are more consistent with the model explaining the ohmic conduction mechanism by the formation of a graded heterojunction structure.