Interfacial reactions of Ni on Si _1-xGe _x (x=0.2,0.3) at low temperature by rapid thermal annealing

The interfacial reaction of Ni with relaxed Si _1-xGe _x (x=0.2,0.3) films in the low temperature range, viz., 300-500°C, has been investigated and compared with that of Ni with Si (i.e., x=0). Ni ₂(Si _1-xGe _x) and Ni ₃(Si _1-xGe _x) ₂ were observed at 300°C whereas a uniform film of Ni(Si _1-xGe _x) was formed at 400°C for both Si _0.8Ge _0.2 and Si _0.7Ge _0.3 substrates. At 500°C, a mixed layer consisting of Ni(Si _1-yGe _y) and Si _1-zGe _z was formed with a relation of z>x>y. 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 _1-xGe _x) (x=0.2,0.3) derived from the transmission electron microscope and sheet resistance results are 19 and 23 μcm, respectively.