Strain dependence of Si-Ge interdiffusion in epitaxial heterostructures on relaxed Si_(1-x)Ge_x substrates

摘要

The strain dependence of Si-Ge interdiffusion in epitaxial Si/Si_(1-y)Ge_y/Si heterostructures on relaxed Si_(1-x)Ge_x substrates has been studied using secondary ion mass spectrometry, Raman spectroscopy, and simulations. At 800 and 880℃, significantly enhanced Si-Ge interdiffusion is observed in Si/Si_(1-y)Ge_y/Si heterostructures (y=0.56, 0.45, and 0.3) with Si_(1-y)Ge_y layers under compressive strain of -1%, compared to those under no strain. In contrast, tensile strain of 1% in Si_(0.70)Ge_(0.30) layer has no observable effect on interdiffusion in Si/Si_(0.70)Ge_(0.30)/Si heterostructures. These results are relevant to the device and process design of high mobility dual channel and heterostructure-on-insulator metal oxide semiconductor field effect transistors.