The First Monolithic Silicon Carbide Active Pixel Sensor Array for Solar Blind UV Detection

This Small Business Innovation Research Phase I project will address the needs of space astronomy, military threat detection, and scientific research for image sensors that are sensitive in the ultraviolet while insensitive in the visible spectrum. This is because solar illuminated backgrounds are orders of magnitude greater than the ultraviolet radiation of interest (solar blocking filters exhibit low UV transmission and scattered light). This program will develop monolithic imaging arrays made of 4H-Silicon Carbide, whose band gap is 3.25 eV versus 1.12 eV for silicon. This results in high UV sensitivity image sensor arrays with very low response in the visible/infrared along with negligible dark current without the need for cooling. Monolithic integration of each individual Schottky detector pixel with its own CMOS readout circuitry eliminates reliability concerns common to bump bonding of thin visible-blind semiconductor materials (GaN etc) with silicon readout integrated circuits (ROICs). In addition, Silicon Carbide is a more mature, defect free, material than Gallium Nitride. Finally, the wide band gap of 4H-SiC results in a higher level of radiation tolerance as compared to Silicon.