Showing papers by "Robert A. Reed published in 2003"

Single-event effects ground testing and on-orbit rate prediction methods: the past, present, and future

Abstract: Over the past 27 years, or so, increased concern over single-event effects (SEEs) in spacecraft systems has resulted in research, development, and engineering activities centered around a better understanding of the space radiation environment, SEE predictive methods, ground test protocols, and test facility developments. This research has led to fairly well developed methods for assessing the impact of the space radiation environment on systems that contain SEE sensitive devices and the development of mitigation strategies either at the system or device level. However, as new technology has emerged, these ground test and predictive methods have certain short falls.

Heavy-ion broad-beam and microprobe studies of single-event upsets in 0.20-/spl mu/m SiGe heterojunction bipolar transistors and circuits

Abstract: Combining broad-beam circuit level single-event upset (SEU) response with heavy ion microprobe charge collection measurements on single silicon-germanium heterojunction bipolar transistors improves understanding of the charge collection mechanisms responsible for SEU response of digital SiGe HBT technology. This new understanding of the SEU mechanisms shows that the right rectangular parallel-piped model for the sensitive volume is not applicable to this technology. A new first-order physical model is proposed and calibrated with moderate success.

An SEU hardening approach for high-speed SiGe HBT digital logic

Abstract: A new circuit-level single-event upset (SEU) hardening approach for high-speed SiGe HBT current-steering digital logic is introduced and analyzed using both device and circuit simulations. The workhorse D-type flip-flop circuit architecture is modified in order to significantly improve its SEU immunity. Partial elimination of the effect of cross-coupling at the transistor level in the storage cell of this new circuit decreases its vulnerability to SEU. The SEU response of this new circuit is quantitatively compared with three other D flip-flop architectures, including the unhardened circuit, a conventional NAND gate based circuit, and a current-sharing hardened (CSH) circuit, at both variable data rate and switching current. The new circuit shows substantial improvement in SEU response over the unhardened version, with little increase in layout complexity and power consumption. While the NAND gate based circuit still shows better SEU response than the other circuits, its high power consumption will preclude its use in space applications. Our results suggest that this new circuit architecture exhibits sufficient SEU tolerance, low layout complexity, and modest power consumption, and thus should prove suitable for many space applications requiring very high-speed digital logic.

3-D simulation of heavy-ion induced charge collection in SiGe HBTs

Abstract: This paper presents the first 3-D simulation of heavy-ion induced charge collection in a SiGe HBT, together with microbeam testing data. The charge collected by the terminals is a strong function of the ion striking position. The sensitive area of charge collection for each terminal is identified based on analysis of the device structure and simulation results. For a normal strike between the deep trench edges, most of the electrons and holes are collected by the collector and substrate terminals, respectively. For an ion strike between the shallow trench edges surrounding the emitter, the base collects appreciable amount of charge. Emitter collects negligible amount of charge. Good agreement is achieved between the experimental and simulated data. Problems encountered with mesh generation and charge collection simulation are also discussed.

Impact of proton irradiation on the static and dynamic characteristics of high-voltage 4H-SiC JBS switching diodes

Abstract: The effects of proton irradiation on the static ( dc) and dynamic (switching) performance of high-voltage 4H-SiC Junction Barrier Schottky (JBS) diodes are investigated for the first time. In contrast to that observed on a high-voltage Si p - i - n diode control device, these SiC JBS devices show an increase (degradation) in series resistance (R/sub S/), a decrease (improvement) of reverse leakage current, and increase (improvement) in blocking voltage after high-fluence proton exposure. Measured breakdown voltages of post-irradiated SiC diodes increase on average by about 200 V after irradiation. Dynamic reverse recovery transient measurements show good agreement between the various dc observations regarding differences between high-power SiC and Si diodes, and show that SiC JBS diodes are very effective in minimizing switching losses for high-power applications, even under high levels of radiation exposure.

Proton tolerance of third-generation, 0.12 /spl mu/m 185 GHz SiGe HBTs

Abstract: We present results on the impact of proton irradiation on the dc and ac characteristics of third-generation, 0.12 /spl mu/m 185 GHz SiGe HBTs. Comparisons with prior technology generations are used to assess how the structural changes needed to enhance performance between second and third generation technology couple to the observed proton response. The results demonstrate that SiGe HBT technologies can successfully maintain their a Mrad-level total dose hardness, without intentional hardening, even when vertically-scaled in order to achieve unprecedented levels of transistor performance.

The effects of operating bias conditions on the proton tolerance of SiGe HBTs

Abstract: The effects of operating bias conditions on the proton tolerance of Silicon–Germanium (SiGe) heterojunction bipolar transistors (HBTs) are investigated for the first time. While this SiGe HBT technology is relatively insensitive to different bias conditions during radiation exposure, the cases with all terminals grounded and with the emitter–base junction reverse-biased show slightly enhanced degradation at proton fluences above 2 × 1013 p/cm2 compared to the other bias configurations, consistent with 2D simulations, and can thus be viewed as worst case conditions.

Current single event effects results for candidate spacecraft electronics for NASA

Abstract: We present data on the vulnerability of a variety of candidate spacecraft electronics to proton and heavy ion induced single event effects. Devices tested include digital, analog, linear bipolar, and hybrid devices, among others.

Current total ionizing dose results and displacement damage results for candidate spacecraft electronics for NASA

Abstract: We present data on the vulnerability of a variety of candidate spacecraft electronics to total ionizing dose and displacement damage. Devices tested include optoelectronics, digital, analog, linear bipolar devices, hybrid devices, analog-to-digital converters (ADCs), and digital-to-analog converters (DACs), among others.

Proton tolerance of multiple-threshold voltage and multiple-breakdown voltage CMOS device design points in a 0.18 /spl mu/m system-on-a-chip CMOS technology

Abstract: The paper presents the results of an investigation of the proton tolerance of the multiple-threshold voltage and multiple-breakdown voltage device design points contained in a 0.18 /spl mu/m system-on-a-chip CMOS technology. The radiation response of the CMOS devices having three different device design configurations are characterized and compared for equivalent gamma doses up to 300 krad(Si), using the threshold voltage, off-state leakage, and effective mobility to assess the dc performance. All three CMOS device configurations show a very slight degradation of threshold voltage and effective mobility with increasing dose. We also present for the first time the frequency response and S-parameters of these RF CMOS devices under proton radiation. The S-parameters and cut-off frequency show little degradation up to 300 krad(Si) total dose. These results suggest that the CMOS devices in this 0.18 /spl mu/m SoC CMOS technology are well-suited for RF circuit applications in an ionizing radiation environment without intentional total-dose hardening.

Proton-induced transients and charge collection measurements in a LWIR HgCdTe focal plane array

Abstract: We compare measurements and modeling of 27 and 63 MeV proton-induced transients in a large-format HgCdTe long wavelength infrared (LWIR) focal plane assembly operating at 40 K. Charge collection measurements describe very limited diffusion of carriers to multiple pixels showing significantly reduced particle induced cross-talk for the lateral diffusion structure.

The operation of 0.35 μm partially depleted SOI CMOS technology in extreme environments

Abstract: We evaluate the usefulness of partially depleted SOI CMOS devices fabricated in a 0.35 μm technology on UNIBOND material for electronics applications requiring robust operation under extreme environment conditions consisting of low and/or high temperature, and under substantial radiation exposure. The threshold voltage, effective mobility, and the impact ionization parameters were determined across temperature for both the nFETs and the pFETs. The radiation response was characterized using threshold voltage shifts of both the front-gate and back-gate transistors. These results suggest that this 0.35 μm partially depleted SOI CMOS technology is suitable for operation across a wide range of extreme environment conditions consisting of: cryogenic temperatures down to 86 K, elevated temperatures up to 573 K, and under radiation exposure to 1.3 Mrad(Si) total dose.

Proton response of low-frequency noise in 0.20 μm 90 GHz fT UHV/CVD SiGe HBTs

Abstract: The influence of proton exposure on the low-frequency noise of 0.20 μm UHV/CVD SiGe HBTs is presented. The noise degradation after irradiation shows a strong dependence on transistor geometry. Our previously developed noise theory is used to understand this behavior, and a comparison is made between these new results on third generation SiGe technology and our prior results on the first generation SiGe technology.

Using proton irradiation to probe the origins of low-frequency noise variations in SiGe HBTs

Abstract: We use proton irradiation to probe the origins of the geometry-dependent variation of low-frequency noise in 120 GHz SiGe heterojunction bipolar transistors (HBTs). Before irradiation, small-sized transistors show a strong variation in noise magnitude across many samples, whereas the noise in larger devices is more statistically reproducible. Although the noise magnitude shows little degradation after 2/spl times/10/sup 13/ p/cm/sup 2/ irradiation, the observed noise variation decreases. Its dependence on both geometry and bias is quantified. This fundamental geometrical scaling effect is investigated using theoretical calculations based on the superposition of generation/recombination (G/R) noise sources.

Operating SOI CMOS technology in extreme environments

Abstract: Partially-depleted SOI CMOS devices fabricated in a 0.35 /spl mu/m technology on UNIBOND material were evaluated for electronics applications requiring robust operation under extreme environment conditions consisting of: low and/or high temperatures, and under substantial radiation exposure. The threshold voltage and effective mobility were determined across temperature for SOI CMOS. The radiation response was characterized using threshold voltage shifts of both the front-gate and back-gate transistors. These results suggest that this 0.35 /spl mu/m partially-depleted SOI CMOS technology Is suitable for operation across a wide range of extreme environment conditions consisting of: cryogenic temperatures down to 86 K, elevated temperatures up to 573 K, and under radiation exposure to 1.3 Mrad(Si) total dose.

Broad Beam and Ion Microprobe Studies of Single-Event Upsets in High Speed 0.18micron Silicon Germanium Heterojunction Bipolar Transistors and Circuits

Abstract: SiGe based technology is widely recognized for its tremendous potential to impact the high speed microelectronic industry, and therefore the space industry, by monolithic incorporation of low power complementary logic with extremely high speed SiGe Heterojunction Bipolar Transistor (HBT) logic. A variety of studies have examined the ionizing dose, displacement damage and single event characteristics, and are reported. Accessibility to SiGe through an increasing number of manufacturers adds to the importance of understanding its intrinsic radiation characteristics, and in particular the single event effect (SEE) characteristics of the high bandwidth HBT based circuits. IBM is now manufacturing in its 3rd generation of their commercial SiGe processes, and access is currently available to the first two generations (known as and 6HP) through the MOSIS shared mask services with anticipated future release of the latest (7HP) process. The 5 HP process is described and is characterized by a emitter spacing of 0.5 micron and a cutoff frequency ff of 50 GHz, whereas the fully scaled 7HP HBT employs a 0.18 micron emitter and has an fT of 120 GHz. Previous investigations have the examined SEE response of 5 HP HBT circuits through both circuit testing and modeling. Charge collection modeling studies in the 5 H P process have also been conducted, but to date no measurements have been reported of charge collection in any SiGe HBT structures. Nor have circuit models for charge collection been developed in any version other than the 5 HP HBT structure. Our investigation reports the first indications of both charge collection and circuit response in IBM s 7HP-based SiGe process. We compare broad beam heavy ion SEU test results in a fully function Pseudo-Random Number (PRN) sequence generator up to frequencies of 12 Gbps versus effective LET, and also report proton test results in the same circuit. In addition, we examine the charge collection characteristics of individual 7HP HBT structures and map out the spatial sensitivities using the Sandia Focused Heavy Ion Microprobe Facility s Ion Beam Induced Charge Collection (IBICC) technique. Combining the two data sets offers insights into the charge collection mechanisms responsible for circuit level response and provides the first insights into the SEE characteristics of this latest version of IBM s commercial SiGe process.

Proton-induced secondary particle environment for infrared sensor applications

Abstract: We present measurements of the proton-induced secondary particle environment in the vicinity of an infrared focal plane array. Measurements were made of the energy depositions from secondary electrons and scattered protons from the interior of a cryogenic test dewar using an infrared detector array. The results are compared with model predictions and analyzed for implications to space-based infrared sensors.

Monte carlo treatment of displacement damage in bandgap engineered HgCdTe detectors

Abstract: The conclusion are: 1 Description of NIEL calculation for short, mid, and longwave HgCdTe material compositions 2 Full recoil spectra details captured and analyzed Importance of variance in high Z materials 3 Can be applied directly to calculate damage distributions in arrays 4 Future work will provide comparisons of measured array damage with calculated NIEL and damage energy distributions 5 Technique to assess the full recoil spectrum behavior is extendable to other materials

Probing proton damage in SOI CMOS technology by using lateral bipolar action

Abstract: We investigate proton damage in SOI CMOS devices on UNIBOND using a variety of lateral bipolar operational modes. We show that the impact of interface states and oxide charge can be more clearly observed using lateral bipolar action than by using normal FET operational characteristics. We also investigate the radiation-induced interface states at the Si/buried oxide interface and oxide charges in the buried oxide of this SOI CMOS technology using the DCIV method.

The impact of system configuration on device radiation damage testing of optical components

Abstract: We report on the significant impact that system configuration had on the radiation damage testing of a light emitting diode-phototransistor pair for the Hubble Space Telescope Wide Field/Planetary Camera 2.

Proton Tolerance of Multiple-Threshold Voltage and Multiple-Breakdown Voltage CMOS Device Design Points in a 0.18 System-on-a-Chip

Abstract: The paper presents the results of an investigation of the proton tolerance of the multiple-threshold voltage and multiple-breakdown voltage device design points contained in a 0.18 system-on-a-chip CMOS technology. The radiation response of the CMOS devices having three different device design configurations are characterized and compared for equivalent gamma doses up to 300 krad(Si), using the threshold voltage, off-state leakage, and effective mobility to assess the dc perfor- mance. All three CMOS device configurations show a very slight degradation of threshold voltage and effective mobility with increasing dose. We also present for the first time the frequency response and -parameters of these RF CMOS devices under proton radiation. The -parameters and cut-off frequency show little degradation up to 300 krad(Si) total dose. These results suggest that the CMOS devices in this 0.18 SoC CMOS tech- nology are well-suited for RF circuit applications in an ionizing radiation environment without intentional total-dose hardening. Index Terms—CMOS, proton radiation, RF technology, system-on-chip.