The effects induced by the gamma-ray responsible for the threshold voltage shift of commercial p-channel power VDMOSFET

Abstract

The vari a tions in the thresh old volt age shift in p-chan nel power VDMOSFET dur ing the gamma ray ir ra di a tion was in ves ti gated in the dose range from 10 to 100 Gy. The in ves ti gations were per formed with out the gate bias and with 5 V gate bias. The de vices with 5 V gate bias ex hibit a lin ear de pend ence be tween the thresh old volt age shift and the ra di a tion dose. The den si ties of ra di a tion-in duced fixed and switch ing traps were de ter mined from the sub-thresh old I-V char ac ter is tics us ing the midgap tech nique. It was shown that the cre ation of fixed traps is dom i nant dur ing the ir ra di a tion. The pos si ble mech a nisms re spon si ble for the fixed and switch ing traps cre ation are also an a lyzed in this pa per.

Probabilistic analysis of voltage divider ratios

“…The solution of this definite integral depends on the limiting values of β for which f(α,β) is non-zero, which again, according to relation (20), depend also on α. This means that fα is different for various ranges of α. β has to satisfy both (18) and (20) for f (α,β) to be non-zero. Which of these two intervals imposes a more stringent limit on the lower or upper bound of β depends on the value of α.…”

“…However, when the two normal distributions have non-zero means, as in the case of normally distributed divider resistances, distribution of the ratio is much more complicated [12,13,14]. It is therefore more convenient to use numerical simulation in this case, assuming that resistances have truncated normal distributions [15,16,17,18,19].…”

“…Limits expressed by(18) are shown as horizontal lines at β = R 2 ' and β = R 2 '', while the limits in(20) are the two hyperbolas β = R 1 '(1/α − 1) and β = R 1 ' '(1/α − 1). The upper and lower bounds to be used in the solution of integral (21) can now be deduced from the graph.The minimum possible vsalue of α, below which f (α,β) is zero, corresponds to the intersection of curves β = R 2 '' and β = R 1 '(1/α − 1), which gives α min = R 1 '/(R 1 ' + R 2 '').…”

Estimation of the lifetime of solar cells in real conditions using accelerated aging under the influence of neutron and gamma radiation

“…Those ef fects are more pro nounced when so lar cells are applied in real con di tions than when tested in lab o ra tory con di tions. For this rea son, test ing the life time of so lar cells is car ried out in lab o ra tory con di tions em ploy ing ac cel er ated ag ing, us ing ra dio ac tive ra di a tion [3][4][5][6].…”