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Showing papers by "Robert A. Reed published in 2011"


Proceedings Article•DOI•
10 Apr 2011
TL;DR: In this paper, experimental results indicate that scaling increases the sensitivity of microelectronics to soft errors from low-energy muons, and simulations suggest an increasing role of muons in the soft error rate for smaller technologies.
Abstract: Experimental results are presented that indicate technology scaling increases the sensitivity of microelectronics to soft errors from low-energy muons. Results are presented for 65, 55, 45, and 40 nm bulk CMOS SRAM test arrays. Simulations suggest an increasing role of muons in the soft error rate for smaller technologies.

69 citations


Journal Article•DOI•
TL;DR: In this article, through-wafer two-photon absorption laser experiments were performed on bulk FinFETs and the drain region dominated the charge collection, with as much as 45 fC of charge collected in the drain regions.
Abstract: Through-wafer two-photon absorption laser experiments were performed on bulk FinFETs. Transients show distinct signatures for charge collection from drift and diffusion, demonstrating the contribution of charge generated in the substrate to the charge collection process. This result was validated through heavy ion testing on more advanced bulk FinFETs with fin widths as narrow as 5 nm. The drain region dominates the charge collection, with as much as 45 fC of charge collected in the drain region.

66 citations


Journal Article•DOI•
TL;DR: In this paper, the authors evaluated the response of graphene materials and devices to 10-keV X-ray irradiation and ozone exposure and found significant radiation-induced increases in the resistance of suspended graphene layers; the charge neutral point of the graphene layer also shifts positively with increasing total dose.
Abstract: We have evaluated the responses of graphene materials and devices to 10-keV X-ray irradiation and ozone exposure. Large positive shifts are observed in the current-voltage characteristics of graphene-on- SiO2 transistors irradiated under negative gate bias. Moreover, significant radiation-induced increases are found in the resistance of suspended graphene layers; the charge neutral point (CNP) of the graphene layer also shifts positively with increasing total dose. Raman spectroscopy shows that similar defects are generated in graphene-on-SiO2 sheets by 10-keV X-ray irradiation and ozone exposure. First principles calculations of the relevant binding energies, and reaction and diffusion barriers for oxygen on graphene, strongly suggest that oxygen adsorption and reactions, along with the resulting p -type doping, can lead to the observed degradation of irradiated or ozone-exposed graphene materials and devices.

64 citations


Journal Article•DOI•
TL;DR: In this article, a new methodology of prediction for SEU based on SET modeling is proposed based on the ADDICT model for predicting single event transients and upsets in bulk transistors and SRAMs down to 65 nm.
Abstract: A new methodology of prediction for SEU is proposed based on SET modeling. The modeling of multi-node charge collection is performed using the ADDICT model for predicting single event transients and upsets in bulk transistors and SRAMs down to 65 nm. The predicted single event upset cross sections agree well with experimental data for SRAMs.

55 citations


Journal Article•DOI•
TL;DR: In this article, the effects of radiation on electronics, with emphasis on the impact of new materials, are reviewed and solutions change significantly as new materials are introduced and feature sizes become smaller.

40 citations


Journal Article•DOI•
TL;DR: In this paper, the authors show that the presence of high-Z materials, like tungsten, can increase the single event upset (SEU) and multiple cell upset (MCU) cross sections of high critical charge (Qcrit) devices exposed to the terrestrial neutron environment because of interactions with high energy ( >; 100 MeV) neutrons.
Abstract: Neutron-induced charge collection data and computer simulations presented here show that the presence of high-Z materials, like tungsten, can increase the single event upset (SEU) and multiple cell upset (MCU)cross sections of high critical charge (Qcrit) devices exposed to the terrestrial neutron environment because of interactions with high energy ( >; 100 MeV) neutrons. Time-of-flight data and computer simulations presented here demonstrate that 14 MeV neutrons do not produce highly ionizing secondary particles. Thus, 14 MeV neutrons can only simulate the SEU response of 65 nm SRAM devices in the terrestrial neutron environment for devices with a Qcrit <; 27fC, and can simulate the 2-bit MCU response to within a factor of two only for very low Qcrit devices, <; 1.2 fC.Additionally, it is shown that 14 MeV neutrons cannot adequately simulate the 3 or more bit MCU response for typical 65 nm SRAM devices.

37 citations


Proceedings Article•DOI•
18 Nov 2011
TL;DR: In this article, the authors consider the effect of the buried insulating layer (buried oxide - BOX) on total ionizing dose (TID) radiation effects, particularly for fully depleted (FD) SOI.
Abstract: Silicon-On-Insulator (SOI) has long been recognized to provide inherent resistance to transient ionizing radiation effects due to the isolation from the substrate. The buried insulating layer (buried oxide - BOX) is also known to introduce problematic considerations for total ionizing dose (TID) radiation effects, particularly for fully-depleted (FD) SOI. Recent work in characterization of TID effects in partially depleted (PD) SOI indicates that the inherently high doping levels of the body region result in insensitivity to TID [1–2]. The pros and cons generally apply to all SOI-based technologies, including thin-film CMOS as well as thick film bipolar, LDMOS, and power MOSFETs. Space and military devices continue to be an opportunity for thin and thick SOI devices where the BOX limits global photocurrets in high dose-rate environments, and local photocurrents in heavy-ion space environments. At the same time, single-event effects (SEE) have become an increasing reliability concern in terrestrial electronics, particularly in sub-65 nm CMOS circuits. Small amounts of charge representing each bit of information, high clock speeds, low operating voltages, and high packing densities all exacerbate the sensitivity to ionizing particles. Terrestrial neutron effects, and more recently direct ionization by protons and muons, are significant considerations in present and emerging electronic devices [3–4], motivating a closer look at SEE in ultra-thin (UT) FDSOI.

36 citations


Journal Article•DOI•
TL;DR: In this article, an incremental enhancement approach that enables various SEU/performance trade-off was demonstrated on the same basic SRAM cell to achieve various degrees of hardness, by the selective utilization of enhancement features.
Abstract: SEU enhancements were introduced into a radiation hardened 90 nm CMOS technology to achieve upset immunity. An incremental enhancement approach that enables various SEU/performance trade-off was demonstrated on the same basic SRAM cell to achieve various degrees of hardness, by the selective utilization of enhancement features. Single event upset testing, as well as MRED simulation, have demonstrated a significant enhancements achieved with a minimal performance penalty.

32 citations


Proceedings Article•DOI•
01 Jul 2011
TL;DR: In this paper, the potential for using the degraded beam of high-energy proton radiation sources for proton hardness assurance testing for ICs that are sensitive to proton direct ionization effects is explored.
Abstract: The potential for using the degraded beam of high-energy proton radiation sources for proton hardness assurance testing for ICs that are sensitive to proton direct ionization effects are explored. SRAMs were irradiated using high energy proton radiation sources (~67-70 MeV). The proton energy was degraded using plastic or Al degraders. Peaks in the SEU cross section due to direct ionization were observed. To best observe proton direct ionization effects, one needs to maximize the number of protons in the energy spectrum below the proton energy SEU threshold. SRIM simulations show that there is a tradeoff between increasing the fraction of protons in the energy spectrum with low energies by decreasing the peak energy and the reduction in the total number of protons as protons are stopped in the device as the proton energy is decreased. Two possible methods for increasing the number of low energy protons is to decrease the primary proton energy to reduce the amount of energy straggle and to place the degrader close to the DUT to minimize angular dispersion. These results suggest that high-energy proton radiation sources may be useful for identifying devices sensitive to proton direct ionization.

31 citations


Journal Article•DOI•
TL;DR: In this paper, the effects of low and medium energy x-rays on back-end-of-line metallization layers, including copper interconnects, W vias, and borophosphosilicate glass (BPSG) and SiO2 passivation layers, were quantified.
Abstract: The effects of 10-keV and 400-keV endpoint-energy bremsstrahlung x-rays have been studied using the Monte Carlo simulator, MRED, for MOS capacitors with HfO2 gate dielectrics and TiN and TaN metal gates. We compute the reduction in dose that occurs for 10-keV x-ray irradiation of thin HfO2 gate dielectrics sandwiched between the metal gate and the Si substrate. We quantify the effects of back-end-of-line metallization layers, including copper interconnects, W vias, and borophosphosilicate glass (BPSG) and SiO2 passivation layers for low and medium energy x-rays. For thick metallization stacks irradiated by 10-keV x-rays, dose enhancement or attenuation can occur, depending on material type and overlayer thicknesses. For similar stacks irradiated with 400-keV endpoint-energy bremsstrahlung x-rays, significant dose enhancement is observed.

20 citations


Proceedings Article•DOI•
10 Apr 2011
TL;DR: In this article, the authors used pulsed laser-induced current transient experiments to understand the mechanisms of single event effects in bulk and fully depleted silicon-on-insulator p-channel FinFETs.
Abstract: Pulsed laser-induced current transient experiments are used to understand the mechanisms of single-event effects in bulk and fully depleted silicon-on-insulator p-channel FinFETs. The drain current transients are significantly larger in the bulk FinFETs than in the SOI devices. Bulk FinFETs collected 270 times more charge than SOI FinFETs. 98% of the charge collected in the bulk FinFETs is generated in the substrate. The rest of the collected charge (2%) is generated in the fins. Most of the collected charge in the SOI FinFets is generated in the fins.

Journal Article•DOI•
TL;DR: In this paper, the pulse widths of single-event transients produced by alpha particles in a 65nm bulk CMOS technology are reported, and the experimental setup and calibration of the alpha particle experiment is described in detail.
Abstract: Pulse widths of single-event transients produced by alpha particles in a 65-nm bulk CMOS technology are reported. The experimental setup and calibration of the alpha particle experiment is described in detail. A focused-ion beam is also utilized to explore how pulse broadening in the test circuit impacts the alpha particle SET measurements. The results of this work show that alpha particles are able to induce transient signals with a width of about 25 ps in this technology.

Journal Article•DOI•
01 Sep 2011
TL;DR: In this article, a 10-keV X-ray irradiation was found to increase oxide growth rate with increasing dose rate, which is attributed to the generation of ozone, which decomposes into molecular oxygen and highly reactive atomic oxygen at the surface of the Si wafer.
Abstract: Enhanced rates of oxide growth have been observed on silicon upon exposure to 10-keV X-ray irradiation. Oxide thicknesses were determined using spectroscopic ellipsometry on irradiated and control samples, and confirmed via X-ray photoelectron spectroscopy. The oxidation rate varied with the radiation total dose and dose rate. The increased oxidation rate is attributed to the generation of ozone, which decomposes into molecular oxygen and highly reactive atomic oxygen at the surface of the Si wafer. The generation of ozone by 10-keV X-rays was found to increase linearly with increasing dose rate. UV irradiation led to similarly enhanced oxidation rates. The potential application of this phenomenon to dosimetry is explored.

Journal Article•DOI•
TL;DR: In this article, experimental cross-section data for the interaction of protons with Al, Co, and Au at intermediate energies are compared with the predictions of the nuclear reaction models CEM03, BIC, Bertini INC, and INCL-ABLA.
Abstract: Experimental cross-section data for the interaction of protons with Al, Co, and Au at intermediate energies are compared with the predictions of the nuclear reaction models CEM03, BIC, Bertini INC, and INCL-ABLA. Fission cross-section data for the interaction of protons with W and Au in the energy range 50 MeV-3 GeV are also compared with the considered models. The study reveals that all of the models are satisfactory in limited ranges. However, of these, the CEM03 code from Los Alamos exhibits the broadest applicability for radiation effects computations.

Proceedings Article•DOI•
01 Sep 2011
TL;DR: In this paper, a complex dependence on the arrival time of the particle strike relative to the word-line clock is observed, which affects the soft-error sensitivity of SRAM cells, and the effect of process variation on the soft error sensitivity is discussed.
Abstract: Process variation affects the soft-error sensitivity of SRAM cells. A complex dependence on the arrival time of the particle strike relative to the word-line clock is observed.

Journal Article•DOI•
01 Sep 2011
TL;DR: In this article, three-dimensional simulations of a 45 nm SOI SRAM cell indicate that the contributions of charge generation and transport in the surrounding oxides have a potentially meaningful effect on the SEU response in nanotechnologies.
Abstract: Three-dimensional NanoTCAD simulations of a 45 nm SOI SRAM cell indicate that the contributions of charge generation and transport in the surrounding oxides have a potentially meaningful effect on the SEU response in nanotechnologies.

Journal Article•DOI•
TL;DR: In this article, the authors investigated the physical nature of the defects responsible for degradation in InAs-AlSb high-electron mobility transistors stressed with hot carriers and found that the devices are most degradation prone in operating conditions with high longitudinal (in the direction of IDS) electric fields in the channel.
Abstract: InAs-AlSb high-electron mobility transistors stressed with hot carriers may exhibit shifts in the peak transconductance toward more negative gate-voltages. The devices are most degradation prone in operating conditions with high longitudinal (in the direction of IDS) electric fields in the channel. Room-temperature annealing, gate current, and channel-mobility measurements suggest the presence of a metastable defect in the top AlSb layer. Device simulations and first-principles quantum-mechanical calculations are used to investigate the physical nature of the defects responsible for degradation. Metastable configurations of substitutional and interstitial oxygen have charge states and transition energies consistent with the degradation trends.


Proceedings Article•DOI•
10 Apr 2011
TL;DR: In this article, the single event performance of a dual-complementary D-type Flip-Flop (DC-DFF) implemented similarly to Dual Interlocked Cell (DICE) without pass-gates is described.
Abstract: This paper describes the single event performance of a dual-complementary D-type Flip-Flop (DC-DFF) implemented similarly to Dual Interlocked Cell (DICE-DFFs), but without pass-gates. Circuit-level modeling indicates that the DC-DFF is resistant to single event transient (SET) capture of errant signals on the data lines while increasing the operating speed, as compared to the DICE-DFF. However, the simulations also predict that the DC-DFF is susceptible to internal single events during data transitions. This susceptibility is not present in basic DICE designs, but is present in standard DFF designs. Heavy ion testing verified the simulations of the internal single-event clock-dependent mechanism in the DC-DFF design. This dynamic clock-dependent mechanism is described in detail.

Journal Article•DOI•
TL;DR: In this paper, Monte Carlo simulations demonstrate that electrons in a Europa-like radiation environment produce single events capable of depositing more than 100 keV in a shielded focal plane array (FPA).
Abstract: Monte Carlo simulations demonstrate that electrons in a Europa-like radiation environment produce single events capable of depositing more than 100 keV in a shielded focal plane array (FPA). Aluminum shielding slows down high energy free space electrons through collisions. Incident electrons can also generate secondary particles within shielding through electromagnetic cascades, nuclear interactions, and other mechanisms. When incident electrons and secondary particles deposit energy in FPA pixels, the result is transient increases in background noise. We compare the energy deposition integral cross sections and estimate the single event effect rate for a range of electron energies incident upon an FPA shielded with 1, 5, and 10 cm of aluminum.