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Single event transient (SET) pulse-widths were measured as a function of linear energy transfer (LET) by using pulse capture circuits and simulated with mixed-mode 3-D device simulations. We found that the carrier recombination process dominates the LET dependence of the pulse-widths. Index Terms--Logic cell, single event transient, SOI.

Waveforms of digital single-event transients, radiation-induced voltage transients in logic gates, can be observed by connecting two transistors to a target logic gate. Additional transistors monitor voltage transients through their drain currents, which can be measured using the conventional 50-[ohm] transmission-line technique widely used for measuring transient currents in single elementary transistors. Experimental results obtained in pulsed-laser irradiation tests demonstrate the validity of the observation technique and clearly reveal the pulse evolution as a function of the laser pulse energy. Index Terms--Integrated circuit radiation effects, pulsed laser irradiation, semiconductor device radiation effects, single event transients (SETs), soft errors, waveform observations.

A scan flip-flop (FF) is designed to observe both single event transient (SET) and single event upset (SEU) soft errors in logic VLSI systems. The SET and SEU soft errors mean the upset caused by latching an SET pulse that originates in combinational logic blocks and the upset caused by a direct ion hit to the FF, respectively. An irradiation test method using the scan FF is proposed to obtain SET and SEU soft-error rates at each FF distributed in logic VLSI systems. A test chip is designed using a 0.2-[micro]m fully-depleted silicon-on-insulator standard cell library. The basic concepts have been validated with Verilog timing simulations. The cell-level implementation costs of the proposed scan FF are estimated to be reasonable. Index Terms--Integrated circuit radiation effects, irradiation test, logic VLSI system, scan architecture, single event transient, single event upset.

A table-based technique for estimating single-event transient pulses is evaluated in the most crucial case for bulk MOSFET technologies where an ion penetrates the drain region. A device model of a bulk MOSFET is built in a 2-D numerical device simulation framework, and heavy-ion-induced transient currents flowing through its drain terminal are calculated. From the currents, single-event transient voltage pulses in an inverter are estimated with the table-based estimation technique. The results are compared with ones simulated in the mixed mode with the same device model and circuit configuration. The estimated are comparable to the results in the mixed-mode device simulations. Moreover, the estimation accuracy can be improved using a drain-capacitance compensation technique. An extrapolation technique based on the drain-voltage dependency of heavy-ion-induced transient currents is also presented to reduce the experimental costs for modeling. Index Terms--Graphical derivation, heavy ions, integrated circuit radiation effects, look-up table modeling, semiconductor device radiation effects, single event transients (SETs), transient currents.

Described is an estimation technique of single event transient voltage pulses in VLSI circuits from heavy-ion-induced transient currents measured in a single MOSFET. Waveforms of the transient voltage pulses are fully estimated by using transient current data obtained in various drain voltage conditions. Modeling of the irradiated device behavior for use in device/circuit simulations is not required. The concept is validated using a 2-D mixed-mode device simulation. Index Terms--Estimation, graphical derivation, heavy ions, integrated circuit radiation effects, semiconductor device radiation effects, simulation, single event transients (SETs), transient currents, voltage pulses.

Current components of heavy-ion-induced transient currents in a 0.2-[micro]m fully-depleted SOI MOSFET are analyzed in the time domain. The analysis demonstrates that the transient currents have another slow-decay current component that is different from the two conventional current components: a prompt discharge current and a slow-decay parasitic bipolar current. The slow-decay component revealed here is a flow of deposited carriers stored in the body region to maintain quasi-neutrality, and it drastically widens the transient pulse. Index Terms--Heavy ions, parasitic bipolar transistor, silicon on insulator (SOI) technology, single event transients, time domain analysis, transient currents.

Effects of homogenous uniaxial and biaxial strains on the thermal oxidation processes of Si with newly developed techniques are discussed. It is found that stress during the thermal oxidation does not cause any change in the electronic states of the oxide, which are characterized by x-ray photoelectron spectroscopy and x-ray absorption near edge structure.