Investigation of Ni(Pt)/Si-cap/SiGe solid phase reaction

Ni(Pt)/Si-cap/SiGe solid phase reaction with various Si cap layer thickness and Ge content has been investigated in this paper. The results suggest that the Si-cap layer needs to be carefully optimized to achieve the lowest sheet resistance (Rs). The thermal stability study shows that Ge atoms out-diffusion results in the strain relaxation and the decrease of Ge content of SiGe layer even after a low temperature post annealing, although the Rs apparently remain constant. After a higher temperature post annealing, the film agglomeration and Ge segregation cause a significant increase in Rs and decrease of compressive strain in SiGe layer.