Reduced pressure-chemical vapor deposition of high quality Ge layers on SiGe/Si superlayers for microelectronics and optoelectronics purposes

摘要

We have investigated the structural properties of Ge thick films grown directly onto SiGe/Si superlayers/Si substrates using a production-compatible reduced pressure-chemical vapor deposition system. The thick Ge layers grown using germane and a low-temperature/high-temperature approach are in a tensile-strain configuration. X-ray-diffraction measurements showed that the Ge layer possesses a litter higher tensile strain as large as 0.31% than L/H conventional approach (0.17%), which is generated during the cooling from the high growth temperature due to the thermal-expansion mismatch between Ge and Si. In addition, we also exhibited the variations of Ge layers with changes of the superlayers. The process described in this letter for making high-quality Ge is uncomplicated and can be easily integrated with standard Si processes.