Optical Characterization of Ge-on-Si Grown by using RTCVD

We have investigated the characterization of Ge-on-Si Grown by using RTCVD. From the HR-XRD analysis, the Ge epi-layer shows good crystalline homogeneity and the lattice parameter of the Ge layer along the growth direction was calculated as 5.654 Å, indicating the compressive strain of 0.07%. The Ge peak Raman shift for each sample indicates compressive strain from the bulk Ge reference. The roll-off in photocurrent after 1600 nm is expected due to the decreased absorption of Ge.