Precursor ion damage and angular dependence of single event gate rupture in thin oxides

Heavy-ion-induced soft breakdown of thin gate oxides

“…The total leakage current is a summation of these paths conducting in parallel. This interpretation is consistent with the observed area dependence of the leakage current and with earlier reports [8]- [10]. Fig.…”

“…Qualitatively, it appears that the electric field required for SEGR/HBD decreases with increasing LET, confirming earlier work in thicker oxides [6]- [8]. is extracted at V.…”

“…1 and 2, it is clear that the postradiation oxide conduction in these thin oxides is a function of both LET and bias (as reported in Ceschia et al [9], [10] and in thicker oxides by Sexton et al [6], [8] and Johnston et al [7]). For both Au and I, the oxides exhibit soft breakdown (SBD) at lower voltages (including 0 V) [8]- [10] and hard breakdown (gate rupture) at voltages greater than 3.5 V. The SBD is indicated by the 10 increase in , increased noise, and the exponential dependence of leakage on (at the higher voltages, -curves appear as nearly straight lines on the log-linear scale). Note also that subsequent traces are roughly parallel.…”

“…Although radiation produces only a modest shift in the threshold voltage of the thin gate oxides used in advanced MOS technology, these thin oxides were still susceptible to radiation effects. In the last few years, pioneering work has uncovered a variety of new radiation-induced effects in thin gate oxides [1]- [10], including radiation-induced leakage current (RILC) in gamma and electron irradiated oxides [1]- [5] and single-event gate rupture (SEGR) [6]- [8] and radiation-induced soft breakdown (RSB) [7]- [10] in oxides exposed to high linear energy transfer (LET) heavy-ion irradiation. Despite this work, the effects of radiation on the reliability of ultrathin oxides ( 4 nm) have not been extensively characterized.…”

X-Ray and Proton Radiation Effects on 40 nm CMOS Physically Unclonable Function Devices

“…4-4(a). unbroken nFET is increased gate leakage current due to proton-induced defect formation [37], [38]. However, Fig.…”