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The effects of device orientation on heavy ion-induced multiple-bit upset (MBU) in 65 nm SRAMs are examined. The MBU response is shown to depend on the orientation of the device during irradiation. The response depends on the direction of the incident ion to the n- and p-wells of the SRAM. The MBU response is simulated using Monte Carlo methods for a space environment. The probability is calculated for event size. Single-bit upsets in the space environment account for 90% of all events with exponentially decreasing probabilities of larger MBU events. Index Terms--Multiple-bit upset, MBU, MCU, SEU, heavy ion, SRAM, MRED, GEANT4, soft error.

Advanced nanocrystal nonvolatile memories have been exposed to heavy ion bombardment. They appear to be promising candidates for future spacecraft electronics. Index Terms--Component, electronics, nanocrystals, nonvolatile memory, radiation effects.

We present the first investigation of low energy (1.75 MeV) proton irradiation in SiGe HBT's and discuss proton energy effects in SiGe HBT technology. The results show that after 1.75 MeV 1 x [10.sup.14] p/[cm.sup.2], a semi-insulating substrate is obtained and the peak quality factor of the monolithic inductors is improved by about 18% at 1.6 GHz. Although large current gain degradation for the SiGe HBT's was observed in the RF bias region after 1 x [10.sup.14] p/[cm.sup.2], the degradation in peak [f.sub.T] is only about 11%. Proton energy studies from 1.75 MeV to 200 MeV in SiGe HBT's suggest that the conventional damage factor can be used to estimate energy-dependent proton-induced radiation damage in this technology. Index Terms--Damage factor, HBT, inductors, proton energy effects, proton tolerance, radiation, SiGe, silicon-germanium.

This paper presents the first investigation of the physical origins of the observed variable proton tolerance in multiple SiGe HBT BICMOS technology generations. We use the combination of an extensive set of newly measured proton data on distinct SiGe HBT BiCMOS technology generations, detailed calibrated 2-D MEDICI simulations for both the SiGe HBT and Si CMOS devices, as well as reverse-bias emitter-base and forward-bias electrical stress data to aid the analysis. We find that the scaling-induced increase in the emitter-base electric field under the spacer oxide in the SiGe HBT is primarily responsible for the degraded radiation tolerance with technology scaling, while the decrease in shallow-trench thickness is largely responsible for the improved nFET radiation tolerance with technology scaling. Index Terms--BiCMOS, bipolar transistor, SBT, proton radiation, shallow trench isolation, SiGe, silicon-germanium.

Historically, proton-induced single-event effects (SEEs) ground test data are collected independent of the orientation of the microelectronic device to the proton beam direction. In this study, we present experimental and simulation evidence that shows an effect of over an order of magnitude on the proton-induced single-event upset (SEU) cross section when the angle of incidence of the proton beam is varied. The magnitude of this effect is shown to depend on the incidence proton energy and the device critical charge. The angular effect is demonstrated for Silicon-On-Sapphire and Silicon-On-Insulator technologies, but would not necessarily be limited to these technologies.

We investigate the proton radiation tolerance of a 0.35-/[micro]m SOI technology on UNIBOND material. The radiation response is characterized by threshold-voltage shifts of the front-gate and back-gate transistors. An increase of the front-gate threshold voltage is observed on the n-channel MOSFETs after irradiation and is attributed to radiation-induced interface states at the front-gate oxide/silicon interface. A double [g.sub.m] peak behavior is observed on the back-gate [g.sub.m]-[V.sub.GS] curves for both n- and p-channel MOSFETs and is attributed to silicon/back-gate oxide interface traps with a delta-function-like distribution in the energy gap. The results suggest this 0.35-[micro]m technology on UNIBOND material performs well in a proton-radiation environment. Index Terms--Interface states, MOSFETs, partially depleted, proton, radiation, SOI, UNIBOND.

We present single-event transient (SET) test data on linear devices under many operational conditions in an attempt to understand the SET generation and characteristics. This is done in an attempt to define a low-cost conservative test methodology to characterize these effects. Index Terms--Bipolar analog integrated circuits, comparators, integrated circuits, ion radiation effects, laser radiation effects, linear circuits, operational amplifiers, radiation effects.

This paper investigates the impact of proton irradiation on the 1/f noise in ultra-high-voltage chemical-vapor deposition SiGe heterojunction bipolar transistors. The relative degradation of 1/f noise shows a strong dependence on device geometry. Both the geometry dependence and the bias dependence of 1/f noise change significantly after exposure to 2 x [10.sup.13] p/[cm.sup.2] protons. An expression describing the 1/f noise is derived and used to explain the experimental observations. Index Terms--1/f noise, proton irradiation, SiGe heterojunction bipolar transistor (HBT).

We present the first experimental results of the effects of 63-MeV proton irradiation on SiGe heterojunction bipolar transistor (HBT) analog and radio-frequency (RF) circuits and passive elements. A SiGe HBT bandgap reference circuit, commonly used to generate stable on-chip voltages in analog ICs, a SiGe HBT voltage-controlled oscillator, a key building block for RF transceivers, and an LC bandpass filter routinely used in RF circuit design were each irradiated to proton fluences as high as 5 x [10.sup.13] p/[cm.sup.2]. The degradation associated with these extreme proton fluences was found to be minimal, suggesting that SiGe HBT technology is robust for these types of circuit applications. Index Terms--Bipolar transistor, circuits, heterojunction bipolar transistor (HBT), passives, silicon germanium (SiGe).

The effects of 63-MeV proton irradiation on SiGe: C heterojunction bipolar transistors (HBTs) are reported for the first time. The dc characteristics and neutral base recombination of these SiGe: C HBTs are investigated for proton fluences up to 5 x [10.sup.13] p/[cm.sup.2]. A comparison is made with SiGe HBTs fabricated in the same technology. Despite the fact that these SiGe: C HBTs degrade significantly during proton exposure, there is no indication that the carbon doping has any significant impact on the radiation response. Index Terms--Neutral base recombination, proton irradiation, SiGe: C heterojunction bipolar transistor (HBTs).

We investigate the proton tolerance of fully depleted silicon-on-insulator (SOI) MOSFETs with H-gate and regular-gate structural configurations. For the front-gate characteristics, the H-gate does not show the edge leakage observed in the regular-gate transistor. An anomalous kink in the back-gate linear [I.sub.D]-[V.sub.GS] characteristics of the fully depleted SOI nFETs has been observed at high radiation doses. This kink is attributed to charged traps generated in the bandgap at the buried oxide/silicon film interface during irradiation. Extensive two-dimensional simulations with MEDICI were used to understand the physical origin of this kink. We also report unusual self-annealing effects in the devices when they are cooled to liquid nitrogen temperature. Index Terms--Fully depleted, H-gate, kink, proton, radiation, self-annealing, SIMOX, SOI MOSFETs.

We present data on recent optocoupler in-flight anomalies and the subsequent ground test irradiation performed. Discussions of the single event mechanisms involved, transient filtering analysis, and design implications are included. Proton-induced transients were observed on higher speed optocouplers with a unique dependence on the incidence particle angle. The results indicate that both direct ionization and nuclear reaction-related mechanisms are responsible for the single events observed.

This paper presents radiation effects characterization performed by the NASA Goddard Space Flight Center (GSFC) on spaceflight candidate 16Mbit DRAMs. This includes heavy ion, proton, and Co60 irradiations on single-chip devices as well as proton irradiation of a stacked DRAM module. Lastly, a discussion of test methodology is undertaken.

As spacecraft unlock the potential of fiber optics for spaceflight applications, system level bit error rates become of concern to the system designer. We present ground test data and analysis on candidate system components.

We present the first experimental results of the effects of 63 MeV proton irradiation on both the lateral and vertical scaling properties of SiGe HBT BiCMOS technology. Three distinct generations of (unhardened) SiGe technology are examined. The first generation SiGe HBTs experience very minor degradation in current gain at proton fluence as high as 2 x [10.sup.13] p/[cm.sup.2]. The second and third generations SiGe HBTs, however, show 60-70% degradation in current gain under similar conditions, suggesting that emitter-base spacer optimization may be required as the technology is scaled. Si nFETs from the first generation SiGe BiCMOS technology are only hard to about 40 krad equivalent gamma dose, and are limited by drain-to-source leakage along the shallow trench edge. The second generation Si nFETs, however, improve with scaling since the shallow trench is thinned, and can withstand up to 150 krad of equivalent dose.

We measure the energy dependence of proton-induced LED degradation using large numbers of devices and incremental exposures to gain high confidence in the proton energy dependence and device-to-device variability of damage. We compare single versus double heterojunction AlGaAs technologies (emitting at 880 nm and 830 nm, respectively) to previous experimental and theoretical results. We also present a critical review of the use of nonionizing energy loss in AlGaAs for predictions of on-orbit degradation and assess the uncertainties inherent in this approach.