Interdiffusion in SiGe/Si Epitaxial Heterostructures

The Si-Ge interdiffusivity in epitaxial strained Si/Si
_1-y
Ge
_y
/strained Si/relaxed Si
_1-x
Ge
_x
and strained Si/relaxed Si
_1-x
Ge
_x
heterostructures was systematically extracted for Ge fractions between 0 and 0.56 over a temperature range of 770 - 920 degC. Boltzmann-Matano analysis was applied to extract interdiffusivity from diffused Ge profiles of strained Si/relaxed Si
_1-x
Ge
_x
heterostructures. TSUPREM-4 was used to fit SIMS profiles and refine the extracted interdiffusivity. Significantly enhanced Si-Ge interdiffusion was observed in Si
_1-y
Ge
_y
layers under compressive strain. These results were incorporated into an interdiffusion model that successfully predicts experimental interdiffusion of various SiGe heterostructures