Pt/Ti/p-InGaAsP NONALLOYED OHMIC CONTACT FORMED BY RAPID THERMAL PROCESSING.

Nonalloyed ohmic contacts of Pt/Ti to 5 x 10 sup (18) cm sup (-3) doped p-InGaAsP (lambda sub g = 1.3microns) have been fabricated by Rapid Thermal Processing of sputter and E-gun deposited metallizations. While the former as-deposited had a rectifying characteristic, the latter showed ohmic behavior prior to any heat treatment, with a specific contact resistance of 4 x 10 sup (-3) ohm cm sup 2. Rapid Thermal Processing at temperatures higher than 400C caused the formation of Ohmic contacts for the sputtered metals also, but with the evaporated metals producing slightly lower contact resistance. The lowest specific contact resistance values of 3.6-5.5 x 10 sup (-4) ohm cm sup 2 for evaporated and sputtered metallizations, respectively, were achieved in both cases as a result of heating at 450C for 30 sec.