Title :
Variation in SEU sensitivity of dose-imprinted CMOS SRAMs
Author :
Stassinopoulos, E.G. ; Brucker, G.J. ; Van Gunten, O. ; Kim, H.S.
Author_Institution :
NASA/Goddard Space Flight Center, Greenbelt, MD, USA
fDate :
12/1/1989 12:00:00 AM
Abstract :
The authors report on an experimental study of dose-induced changes in SEU (single-event-upset) sensitivity of CMOS static RAMs. Two time regimes were investigated following exposure of memories to cobalt-60 gamma rays: the near term, within a few hours after exposure, and the long term, after many days. Samples were irradiated both at room and at liquid nitrogen temperatures. The latter procedure was used in order to freeze in the damage state until SEU measurements could be made prior to annealing. Results show that memories damaged by dose are more sensitive to upsets by heavy ions. The induced changes are substantial: threshold linear energy transfer (LET) values decreased by as much as 46% and asymptotic cross sections increased by factors of 2 to 4 (unannealed samples)
Keywords :
CMOS integrated circuits; gamma-ray effects; integrated memory circuits; ion beam effects; radiation hardening (electronics); random-access storage; 77 K; 60Co gamma rays; SEU sensitivity; asymptotic cross sections; dose-imprinted CMOS SRAMs; dose-induced changes; experimental study; gamma rays; induced changes; long term; near term; room temperature; single-event-upset; static RAMs; threshold linear energy transfer; time regimes; upsets by heavy ions; Annealing; Energy exchange; Extraterrestrial measurements; Gamma rays; Nitrogen; Random access memory; Satellites; Space vehicles; Steady-state; Temperature sensors;
Journal_Title :
Nuclear Science, IEEE Transactions on
