Enhanced phase stability and morphological stability of Ni(Si,Ge) on strained Si_(0.8)Ge_(0.2)

摘要

NiSi_(0.8)Ge_(0.2) film formed on a strained Si_(0.8)Ge_(0.2) layer epitaxially grown on a Si(100) substrate wafer is morphologically stable up to 750℃. The NiSi_(0.8)Ge_(0.2) film is found to be strongly oriented along its <010> direction. This remarkable stability is thus possibly caused by the tendency of an epitaxial alignment between the NiSi_(0.8)Ge_(0.2) film and the Si_(0.8)Ge_(0.2) layer. The presence of Ge in NiSi forming the ternary solution NiSi_(0.8)Ge_(0.2) hinders the formation of NiSi_2 even at 850℃.