Toward Monolithic GaN on Si Inter-Sub-Band Infrared Optoelectronics

We have successfully demonstrated the first CMOS-compatible monolithic epitaxial integration of GaN-based infrared (IR) detectors on Si. The device is a GaN/AlGaN quantum cascade detector (QCD) grown selectively in windows on a 4-in Si (111) substrate using plasma-assisted molecular beam epitaxy. The CMOS compatibility of the QCD growth method was verified by applying it to Si circuitry fabricated on (100) surface of a double hetero-oriented silicon on insulator (SOI) substrate. The photo signal, centered at a wavelength of 4.6 <tex-math notation="LaTeX">μ m </tex-math> , was measured at 110 K. The zero-bias responsivity of 81 <tex-math notation="LaTeX">μ A </tex-math> /W at 18 K and detectivity of <tex-math notation="LaTeX">1.2× 10^7 </tex-math> Jones were recorded.