Title :
Comparison of enhanced device response and predicted X-ray dose enhancement effects on MOS oxides
Author :
Fleetwood, D.M. ; Beutler, D.E. ; Lorence, L.J., Jr. ; Brown, D.B. ; Draper, B.L. ; Riewe, L.C. ; Rosenstock, H.B. ; Knott, D.P.
Author_Institution :
Sandia Nat. Labs., Albuquerque, NM, USA
fDate :
12/1/1988 12:00:00 AM
Abstract :
The response of MOS capacitors to low- and medium-energy X-ray irradiation is investigated as a function of gate material (TaSi or Al), oxide thickness, and electric field. The measured device response is compared to the predicted response. In comparisons of 10-keV X-ray and Co-60 irradiations of Al-gate MOS capacitors at an oxide electric field of 1 MV/cm, predictions and experiments agree to within better than 20% for oxide thicknesses ranging from 35 to 1060 nm. For capacitors with TaSi/Al gates, they agree to within better than 30% at 1 MV/cm, with the largest differences occurring for 35-nm gate oxides. At other electric fields, the disagreement between experiment and prediction increases significantly for both Al- and TaSi/Al-gate capacitors. For medium-energy (~100-keV average photon energy) X-irradiations, the enhanced device response exhibits a much stronger dependence on endpoint bremsstrahlung energy than expected from TIGERP or CEPXS/ONETRAN simulations. Implications for hardness assurance testing are discussed
Keywords :
X-ray effects; metal-insulator-semiconductor structures; oxidation; Al-SiO2-Si; CEPXS/ONETRAN; MOS capacitors; TIGERP; TaSi-Al-SiO2-Si; X-ray dose enhancement effects; X-ray irradiation; endpoint bremsstrahlung energy; enhanced device response; hardness assurance testing; oxide electric field; oxide thickness; Computational modeling; Computer simulation; Laboratories; MOS capacitors; MOS devices; Monte Carlo methods; Predictive models; Spontaneous emission; Testing; Very large scale integration;
Journal_Title :
Nuclear Science, IEEE Transactions on
