Simultaneous fabrication of very low resistance ohmic contacts to n-InP and p-InGaAs

A process to simultaneously form high-quality ohmic contacts to n-InP and p-InGaAs has been developed. Ti-Au metallization was applied to n-InP following an Ar+-sputter etching treatment and to p-InGaAs after Zn diffusion from doped spin-on glass. Utilizing a selective-wet etching step for the p-type material permits simultaneous fabrication of these contacts with specific contact resistances of well below 1*10-6 Omega cm2