High quality silicon-germanium-on-insulator wafers fabricated using cyclical thermal oxidation and annealing

摘要

An improved fabrication scheme for forming strained SiGe on insulator (SGOI) is demonstrated. Cyclical thermal oxidation and annealing (CTOA) process is introduced to mitigate issues associated with surface roughening and nonuniformity due to increased germanium (Ge) content during SiGe oxidation. Annealing in an inert ambient can be introduced between each oxidation phase to homogenize the Ge content. The root-mean-square surface roughness of the SGOI layer is evaluated to be 0.41 nm. With CTOA, a high quality SGOI substrate is obtained. This technique is promising for the fabrication of dislocation-free SGOI layers for applications in high mobility metal-oxide-semiconductor field-effect transistors.