Complementary Metal Oxide Semiconductor-Compatible SiGe Photodetectors on Ge-Condensed Silicon–Germanium-on-Insulator Templates for Silicon Photonic Integrated Circuits

Silicon–germanium-on-insulator (SGOI) photodetectors are a promising technology for integrated silicon photonics. This work introduces a cost-effective method for fabricating high-performance SGOI photodetectors with a high germanium content (∼40%). The process begins with the formation of ultrathin (∼6 nm) UT-SGOI substrates exhibiting excellent crystalline and morphological quality, achieved through an optimized low-temperature thermal condensation of SiGe/SOI layers. These substrates serve as high-quality templates for the epitaxial growth of thick SGOI photodetectors (up to 800 nm), as confirmed by AFM and TEM analyses. Electrical and optoelectronic characterizations reveal key performance features: low dark current, high photosensitivity, fast photoresponse, and robust stability at low bias. These results highlight the strong potential of this scalable approach for the development of advanced, complementary metal oxide semiconductor-compatible optoelectronic devices tailored for next-generation silicon photonics.