EXTREMELY LOW-RESISTANCE AU MN/NI/AU OHMIC CONTACT TO P-GAAS/

p-type alloyed ohmic contacts of Au/Mn/Ni/Au have been fabricated for application to compound semiconductor devices. Extremely low resistanc e contacts to 3X10(19) cm(-3) Be-doped p-GaAs were achieved by electro n-beam evaporation and rapid thermal annealing. Contacts were thermall y stable, and the contact resistance remained below 0.04 Omega mm in t he temperature range from 360 to 450 degrees C. Annealing at 400 degre es C for 40 s resulted in a minimum contact resistance of 0.012 Omega mm, corresponding to a specific resistivity of 1.6X10(-8) Omega cm(2), which is very close to the theoretical predictions. The mechanism of formation of Au/Mn ohmic contacts was discussed, based on Auger electr on spectroscopy data. (C) 1995 American Vacuum Society.