Sem irradiation for hardness assurance screening and process definition

Abstract
Low-energy electron irradiation of complementary metal-oxide semiconductor (CMOS) devices has been correlated to cobalt-60 gamma irradiation in terms of oxide space charges and interface states.1 This paper reports on the results obtained using the low-energy electron beam of a standard commercial scanning-electron-microscope (SEM) for in-process hardness assurance screening and as a tool for rapid evaluation of process variations designed to improve total-dose radiation hardness. The techniques for SEM testing are described, and the results of correlation studies of radiation effects produced by the SEM, gamma radiation (Co-60), and 106-eV sources compared. The variance in total dose radiation hardness over a single wafer and from wafer to wafer has been investigated for the CMOS CD-4007 array and the results are reported.