Selective Epitaxial Growth of Ge-on-Si for Photodiode Applications

• Main Authors: Kim, Meekyung, Olubuyide, Oluwamuyiwa, Yoon, Jung, Hoyt, Judy
• Format: Conference Proceeding
• Language: English
• ISSN: 1938-5862; 1938-6737
• DOI: 10.1149/1.2986843

The goal of this work is to study and optimize the growth parameters for Ge-on-Si for photodiodes operating at 1.55 um. Approximately 1 um-thick, relaxed Ge is grown in exposed Si regions on oxide-patterned Si wafers. Germanium selectivity, faceting, morphology, and threading dislocation density are investigated as a function of growth and processing conditions. Ge faceting was reduced by increasing the growth temperature and germane partial pressure, and at the optimized growth condition of 750{degree sign}C and 10T, an RMS surface roughness of 1.3 nm was obtained for 10 x 10 um AFM scans. Threading dislocation density was reduced for structures smaller than 5 um, but the dislocation density depends on post-growth annealing conditions and Ge film thickness.