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A voltage-controlled-oscillator (VCO) circuit has been designed for radiation-hardened-by-design (RHBD) single-event transient (SET) mitigation. The RHBD technique, which can be readily implemented in mixed-signal phase-locked loops and delay-locked loops, is shown to substantially improve the single-event performance of the VCO while decreasing the rms phase jitter due to power supply noise. Additionally, using the probabilistic analysis technique presented, the RHBD VCO shows a maximally improved SET response over that of the conventional VCO, decreasing the output phase displacement to below the nominal phase jitter. Index Terms--Delay-locked loops, phase-locked loops, radiation effects, radiation hardening, single-event transients, voltage-controlled oscillators.

Single-photon (SPA) and two-photon laser absorption (TPA) techniques are established as reliable, effective methods to study specific single-event (SE) phenomena in advanced CMOS technologies. However, dense metal-fill in these nanoscale processes can prevent the use of top-side SPA in some cases. This paper demonstrates a novel methodology enabling top-side laser SPA single-event effects (SEEs) measurements in the presence of dense metal-fill for a test circuit fabricated in a commercial 90 nm CMOS process and validates it using unimpeded, through-wafer TPA approach. This is achieved by measuring and comparing the SEU thresholds for the sample circuit using both techniques. Index Terms--Complementary metal-oxide-semiconductor (CMOS), laser, metal-fill, single event (SE), single-photon absorption (SPA), two-photon absorption (TPA).

An on-chip charge-collection measurement circuit has been designed and fabricated in a 130 nm bulk CMOS process. Laser testing is used to verify the effectiveness of the on-chip charge-collection circuit technique for characterizing single event charge collection in advanced technologies. The on-chip charge-collection measurement circuit is used as an investigative tool for examining the effects of parasitic bipolar amplification for deep.submicron PMOS devices. Index Terms--Charge collection, [n.sup.+] diode, NMOS, n-well potential collapse, [p.sup.+] diode, parasitic bipolar transistor, PMOS, single event characterization.

The presence of single event (SE) induced interconnect crosstalk has been measured and demonstrated experimentally using single and two photon laser absorption techniques in the IBM 90 nm CMOS9SF process. The dependency of SE interconnect crosstalk on the interconnect length and on the amount of deposited charge has been quantified through 3D mixed-mode simulations at this technology for two different supply voltages. Experimental and simulation results show this effect to increase the cross-section susceptible to SEs requiring careful design considerations to assure desired hardness levels. Index Terms--Complementary metal-oxide-semiconductor (CMOS), interconnect crosstalk, single event (SE), technology computer aided design (TCAD).