The interfacial reaction of Ni with relaxed Si 1Ϫx Ge x ͑xϭ0.2,0.3͒ films in the low temperature range, viz., 300-500°C, has been investigated and compared with that of Ni with Si ͑i.e., xϭ0͒. Ni 2 (Si 1Ϫx Ge x ͒ and Ni 3 (Si 1Ϫx Ge x ) 2 were observed at 300°C whereas a uniform film of Ni͑Si 1Ϫx Ge x ͒ was formed at 400°C for both Si 0.8 Ge 0.2 and Si 0.7 Ge 0.3 substrates. At 500°C, a mixed layer consisting of Ni(Si 1Ϫy Ge y ) and Si 1Ϫz Ge z was formed with a relation of zϾxϾy. Sheet resistance measurement results show that the silicided film attains its lowest value at an annealing temperature of 400°C. The approximate values of the resistivity of the corresponding uniform Ni(Si 1Ϫx Ge x ) (xϭ0.2, 0.3) derived from the transmission electron microscope and sheet resistance results are 19 and 23 ⍀ cm, respectively.