Abstract: Low resistance contacts for microelectronic devices such as field effect transistors are formed by defining an area on a face of a semiconductor substrate, and forming a layer of an alloy on the defined area wherein the alloy comprises a first material and a second material which may be separated by a segregating step. By doping the alloy layer, a diffusion step may be used to form shallow doped regions in the semiconductor substrate. The alloy is segregated thereby forming a first layer comprising the first material on the defined area, and a second layer comprising the second material. In a preferred embodiment, the alloy comprises a compound of silicon and germanium. The alloy may be segregated by oxidizing the silicon thereby forming a first layer of germanium and a second layer of silicon dioxide. The germanium has a low bandgap thereby providing a low resistance contact to the silicon substrate. Accordingly, a low resistance contact on a shallow doped portion of a semiconductor substrate is provided.