GERMANIUM-DOPED AND TELLURIUM-DOPED GAAS FOR NONALLOYED P-TYPE AND N-TYPE OHMIC CONTACTS

Epitaxial ohmic contacts to GaAs were grown by liquid phase epitaxy. H eavily Ge-doped GaAs was grown to prepare ohmic contacts to p-GaAs whi le Te was used for the n-type contacts. Hall measurements were carried out for the samples grown from melts in which the mole fraction of Ge was varied between 1.55 atomic % and 52.2 atomic %, while the Te mole fractions varied between 0.03% and 0.5%. Specific contact resistance, r(c), as low as r(cp) = 2.9 X 10(-6) ohm-cm(2) for Ge doping of p = ( N-a-N-d) = 6.0 x 10(19) holes/cm(3) was measured for p-contracts and r (cn) = 9.6 x 10(-5) ohm-cm(2) was measured for Te doping of n = (N-d-N -a) = 8.9 x 10(18) electrons/cm(3) for GaAs metallized with non-alloye d contacts of Ti/Al. (C) 1995 American Institute of Physics.