Radiation Hard, High Precision, Agile Star Tracker

In this program, Voxtel will demonstrate SOI-CMOS imagers for high-performance star tracking applications. Fabricating CMOS imagers on SOI wafers, allows the device and detector layers to be separated with an insulating layer, so each can be individually optimized and operated with separate ground returns. High QE and high MTF come from backside illumination and depleting the entire volume of detector through substrate bias and high resistivity silicon. SOI-CMOS circuits offer immunization from radiation and SOI-CMOS reduces parasitic capacitances, which eliminates substrate bounce, and transient coupling problems. SOI's planar structure also makes it easier to passivate surfaces for low dark-current. This advantage, in turn, makes the device more resistant to ionizing radiation. SOI also allows ADCs and other functions to be easily integrated on chip without degrading imaging performance. The resulting imagers have higher operating speeds, lower readout noise, and lower fixed-pattern-noise. In Phase I, we will fabricate, characterize, and radiation test prototype SOI CMOS imagers, and we will demonstrate how high frame rate, variable integration time, dynamic windowing enables tracking during high-rate slewing. In Phase II, we will fabricate a fully-functional 2Kx2K, 12-micron pixel SOI-CMOS star-tracking imagers, and we will perform extensive radiation and reliability testing.