关键词：电子信息；半导体；光电探测器；锗硅
摘 要：We have investigated for the first time the electrical properties of metal-semiconductor-metal (MSM) photodectors fabricated using black silicon- germanium on silicon substrate (Si1-xGex/Si) for I-V, optical response, external quantum efficiency (EQE), internal quantum efficiency (IQE), and responsivity and reflectivity. Silicon-germanium (Si1-xGex)/Si with variations of Ge were blackened by metal enhanced chemical etching (MECE) using nanometer- scale gold particles as catalyst and HF:H2O2:CH3COOH solution as etchant. The etched surface was black, textured, and showed strong suppression of reflectivity. These properties are consistent with Si1-xGex becoming highly micro-structured due to metal catalysis and wet etching. Using the blackened SiGe/Si, MSM photodiodes were fabricated and tested. The lowering of reflection using a U.S. Army Research Laboratory (ARL)-developed technique has helped the enhancement of absorption in Si1-xGex to provide increased optical response, which is an important milestone towards practical, extended wavelength (approximately 2 microns) electro-optical applications.