ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
Results of x-ray and 60Co-γ irradiations on differently processed metal-oxide-semiconductor (MOS) capacitors are carried out. From experiments at 80 K, the field-dependent charge yield fH(E) and the ionization coefficient K are found. In addition, a simple method is described for calculating the hole trapping factor A. For this purpose, just the measured values of the midgap voltage shifts after irradiation at 80 K and room temperature (RT) are used. The investigations of oxide charge buildup Qfr and interface state generation Dit by x-ray irradiation at RT indicate that samples subject to high-temperature (HT) annealing exhibit a more sensitive interface and a less sensitive bulk of the oxide than those not subject to this step. This is found to be in contrast to results of 60Co-γ irradiations at RT. In this case, samples subject to HT annealing show higher sensitivities of the interface and the oxide bulk than corresponding samples without HT annealing. Independent of technology and oxide thickness, the oxide bulk and the interface are more sensitive to x-ray irradiation than to 60Co-γ irradiation. The dependency of the midgap voltage shift, the interface state density and the hole trapping factor on oxide thickness dox is shown. For both x-ray and 60Co-γ irradiation the same relationships ΔUMG∝dnox; ΔDit∝dn−1ox; A∝dn−2ox (n=2.6) are found (ΔUMG is the midgap voltage shift). Differences between x-ray and 60Co-γ irradiations occur in the coefficients of the ΔUMG, ΔDit, and A vs dox proportionalities.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.334763
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