The First JFET-Based Silicon Carbide Active Pixel Sensor UV Imager

Solar-blind ultraviolet (UV) imaging is needed in the fields of astronomy, national defense, and bio-chemistry. United Silicon Carbide, Inc. proposes to develop a monolithic, solar-blind UV image sensor with 320 x 256 pixels on a 25 micron pitch with a frame rate of 50 frames per second and pixel fill factor over 80%. A silicon carbide (SiC) integrated circuit technology that is compatible with production in commercial silicon fabs will be used to fabricate the sensors. SiC is an ideal choice because of 1) its material properties that lead to high UV quantum efficiency while being inherently insensitive to visible and near IR light, negligible dark current up to high temperatures, and excellent radiation tolerance and 2) technological maturity demonstrated by commercially available 4-inch wafers and previous demonstrations of SiC integrated circuits by NASA, United Silicon Carbide Inc. and others. Monolithic integration improves sensor reliability and performance over hybrid approaches and the manufacturability of the n-channel JFET fabrication process provides a clear path to commercializing the technology. In addition to producing monolithic solar-blind UV sensors, the underlying SiC integrated circuit technology being developed has numerous harsh environment analog sensing and electronics applications.