Radiation-Hard CCD Detectors and Imagers for Space Applications

Silicon-on-insulator (SOI) materials have been used extensively to fabricate electronic circuitry which must operate in harsh radiation environments. Spire proposes to extend the advantage of radiationi hardness to highly efficient visible light detectors andimagers by building them on SOI substrates produced by the SIMOX (Separation by IMplantation of OXygen) process. Recent advances in SIMOX technology have resulted in the commercial availability of very high quality SOI substrates. Among these advances has been Spire's development of a low energy SIMOX (LES) processing yielding ultra-thin structures with very low defect density. The first SIMOX-based n-on-p photodiodes capable of efficient visible light detection were fabricated at Spire, where it has also been shown that the silicon top layer thickness can be adjusted to confer wavelength selectivity on these photodiodes. In Phase I several test structures, including CCDs, will be fabricated on high-quality SIMOX substrates, then their electrical and optical performance will be measured before and after irradiation and compared to that of conventional detectors. In Phase II, detector design will be perfected, fabrication processes optimized, and advanced, radiation-hard CCD imagers constructed on SIMOX wafers will be demonstrated.