Comparison of 60Co Response and 10 KeV X-Ray Response in MOS Capacitors

Recently there has been great practical interest in using low energy (10 keV) x-rays rather than the usual 60Co for radiation testing of microelectronic circuits. In this work we examine some of the mechanisms underlying the radiation response of MOS capacitors in these two environments. Specifically we measure the thickness dependent dose enhancement in thin SiO2 films, and we measure the field dependence of the recombination. We found significant dose enhancement for 10 keV x-rays for thin oxides, and the recombination is generally greater at field of practical interest for 10 keV x-rays than for 60Co. The implications of these results for device testing are discussed.