The surface roughness, ρ, of alloyed AuGeNi metallizations to n-type InP have been measured and compared to the specific contact resistance, rc. It was found that p was large for annealing temperatures above 370°C. Below 370°C the surface was smooth. The maximum value of p (120 nm) coincided with the minimum value of rc (7×10-8 Ωcm2) at 420°C annealing. In addition, outgrowths (∼2–4 μm in height), devastating for any further device processing, were observed for annealing temperatures between above 410°C. Using AES it was found that the outgrowths contained a large amount of Au, In and P with the original, as-deposited AuGeNi metallization lying on top. A two step annealing process was developed in order to overcome the outgrowth problem. In the first step the AuGeNi metallization was annealed for long times at a low temperature 370°C, which is the onset of low rc and large p. In the second step a short annealing at 500°C was employed to congruently melt the Au-In binary phase formed at 370°C. It was found that p remained in the order of 120 nm, but no outgrowths were observed and rc was further reduced to 5×10-8 Ωcm2.