Effects of high temperature rapid thermal annealing on Ge films grown on Si(001) substrate

Tensile strain, crystal quality, and surface morphology of 500 nm thick Ge films were improved after rapid thermal annealing at 900 ℃ for a short period (< 20 s). The films were grown on Si(001) substrates by ultra-high vacuum chemical vapor deposition. These improvements are attributed to relaxation and defect annihilation in the Ge films. However, after prolonged (>20 s) rapid thermal annealing, tensile strain and crystal quality degenerated. This phenomenon results from intensive Si–Ge mixing at high temperature.