Radiation damage of 1.0 mm CMOS VLSI as a function of latchup immunity

Abstract

The radiation damage of CMOS VLSI as a function of latchup immunity has been examined. Substantial effects of neutrons and electrons on I/sub L/ (latchup current) have been found. There is an increase of I/sub L/ with neutron and electron dosage. A nonnegligible restoration was observed after subsequent annealing. The increase of I/sub L/ was found to be caused by degradation of I/sub C/ (h/sub FE/). The degradation of I/sub c/ was observed as a function of base width. The degradation of I/sub c/ was absorbed principally by volume recombination rather than surface recombination. There is no problem with the latchup immunity of CMOS VLSI due to irradiation. From the manufacturer's point of view, this result suggests a way of improving latchup immunity for advanced CMOS VLSIs.<>