THE ACHIEVEMENT OF NEAR-THEORETICAL-MINIMUM CONTACT RESISTANCE TO INP

We have investigated the electrical and metallurgical behavior of the InP/Au/Ni contact system. We show that when a layer of Au, 100 angstro m or more in thickness, is introduced between n-InP and Ni contact met allization, specific contact resistivity R(c) values in the low 10(-8) OMEGA cm2 range are achieved after sintering. It is suggested that th ese ultralow values of R(c) are due to the presence, at the metal-InP interface, of a Ni3P layer combined with a stoichiometry change in the InP surface. We show, in addition, that it is possible to achieve ver y low R(c) values with this system without incurring device destroying sinter-induced metallurgical interdiffusion.