Title :
Forward and reverse characteristics of irradiated MOSFETs
Author :
Paccagnella, A. ; Ceschia, M. ; Verzellesi, G. ; Betta, G. F Dalla ; Bellutti, P. ; Fuochi, P.G. ; Soncini, G.
Author_Institution :
Dipartimento di Elettronica e Inf., Padova Univ., Italy
fDate :
6/1/1996 12:00:00 AM
Abstract :
pMOSFETs biased with Vgs<Vgd during Co 60 γ irradiation have shown substantial differences between the forward and reverse subthreshold characteristics, induced by a non-uniform charge distribution in the gate oxide. Correspondingly, modest differences have been observed in the over-threshold I-V characteristics. After irradiation, the forward subthreshold curves can shift at higher or lower gate voltages than the reverse ones. The former behaviour has been observed in long-channel devices, in agreement with the classical MOS theory and numerical simulations. The latter result has been obtained in short-channel devices, and it has been correlated to a parasitic punch-through conduction mechanism
Keywords :
MOSFET; carrier density; electric charge; gamma-ray effects; interface states; semiconductor device models; semiconductor-insulator boundaries; Co; Co60 γ irradiation; Si-SiO2; forward characteristics; gate oxide; irradiated MOSFETs; long-channel devices; nonuniform charge distribution; over-threshold I-V characteristics; p-channel MOSFETs; pMOSFETs; parasitic punch-through conduction mechanism; reverse characteristics; short-channel devices; subthreshold characteristics; CMOS technology; Conductivity; Interface states; Ionizing radiation; MOS capacitors; MOS devices; MOSFET circuits; Numerical simulation; Threshold voltage; Voltage measurement;
Journal_Title :
Nuclear Science, IEEE Transactions on
