Study on Ohmic Contact to Thin and Low-Doped N-GaAs Semiconductor

Ni/Ge/Au/Ni/Au and Pd/In ohmic contacts on bulk-doped N-GaAs semiconductor (Nd=10¹⁸cm^-3) and Ion-implanted N-GaAs semiconductor (dose=8×10¹²cm², implanted depth d=0.2μm are successfully fabricated. The experimental results and the contact mechanism are discussed. The alloyed contacts display long-term stability with low contact resistivity (10⁶cm² for 10¹⁸cm^-3 doping, 10^-3Ωcm² for 8×10¹²cm² implantation). The fabrication procedure is compatible with GaAs device technology.