Design and optimization of NUV-enhanced 4H-SiC separate-absorption-charge-multiplication avalanche photodiodes

High sensitivity near-ultraviolet (NUV) avalanche photodiodes operating at wavelengths longer than 300 nm are useful for various applications, including surface exploration of Ocean Worlds and other planetary bodies via Raman spectroscopy. 4H-SiC has long been established as a proven UV detector technology; however, the responsivity of 4H–SiC avalanche photodiodes (APDs) diminishes dramatically at wavelengths longer than ≈ 280 nm due to its weak absorption at wavelengths approaching the indirect bandgap. The authors will present on the design and optimization of 4H-SiC separate absorption, charge and multiplication (SACM) APDs for broadband absorption from 266 to 340 nm.