High-Performance Back-Illuminated Ge_0.92Sn_0.08/Ge Multiple-Quantum-Well Photodetector on Si Platform For SWIR Detection

Recently, high-performance GeSn photodiodes (PDs) with external light illuminated on the device's top surface have been demonstrated various platforms. However, for image sensing systems a focal-plane array (FPA), front-illuminated sensors usually suffer from area limitations. Here, we report back-illuminated Ge0.92Sn0.08/Ge multiple-quantum-well (MQW) p-i-n PD 300-mm silicon substrate, which was realized entirely by complementary metal-oxide-semiconductor (CMOS) compatible processes. A broadband photoresponse between 1,000-2,100 nm observed, and responsivity is 0.2850 0.0085A/W at 1,550 2,000 nm, respectively. specific detectivity larger than 109 cm·Hz1/2/W achieved 1,050 1,900 nm, covering all conventional telecommunication bands (O to U band). Furthermore, influence of anti-reflective layers also studied in detail. The result shows black Si (b-Si) enhances more photocurrent 1,000-1,500 nm while SiO2 layer (400-nm-thickness) increases current beyond 1,500 nm. 3-dB bandwidth calculated be up 8 GHz mesa diameter 20 μm −2 V. Our experiments high-detectivity high-speed GeSn/Ge MQW potential applications operated short-wave infrared (SWIR) range.