摘要 |
The present invention discloses a method of SiGe epitaxy with high germanium concentration, a germanium concentration can be increased by reducing the percentage of silane and germane during introduction silane and germane. With the same flow of germanium source, the germanium concentration is significantly increased as the germane flow is reduced, therefore a defect-free SiGe epitaxial film with a germanium atomic percentage of 25˜35% can be obtained. The present invention can balance epitaxial growth rate and germanium doping concentration by using existing equipments to obtain a high germanium concentration, and the epitaxial growth rate is only reduced a little, which can keep the SiGe epitaxial layer having no defect to meet the requirements of devices and can maintain sufficient throughput. |