A5020182377- Radiation Effects in Electronics
- Semiconductor materials and devices
- VLSI and Analog Circuit Testing
- Advanced DC-DC Converters
- Integrated Circuits and Semiconductor Failure Analysis
- Silicon Carbide Semiconductor Technologies
- Low-power high-performance VLSI design
- Electrostatic Discharge in Electronics
- Multilevel Inverters and Converters
- Wireless Power Transfer Systems
- Risk and Safety Analysis
- Technology Assessment and Management
- Advancements in Semiconductor Devices and Circuit Design
- Systems Engineering Methodologies and Applications
- Advanced Power Amplifier Design
- Electromagnetic Compatibility and Noise Suppression
- Software Reliability and Analysis Research
- Microgrid Control and Optimization
- Induction Heating and Inverter Technology
- GaN-based semiconductor devices and materials
- Advanced Battery Technologies Research
- Analog and Mixed-Signal Circuit Design
- Radio Frequency Integrated Circuit Design
- Reliability and Maintenance Optimization
- Radiation Detection and Scintillator Technologies
Vanderbilt University
2015-2025
University School of Nashville
2022
University of Tennessee at Chattanooga
2014
University of Arizona
1991-2003
University of Colorado Boulder
1987-2003
University of Colorado System
1986
Abstract Ultrawide‐bandgap (UWBG) semiconductors, with bandgaps significantly wider than the 3.4 eV of GaN, represent an exciting and challenging new area research in semiconductor materials, physics, devices, applications. Because many figures‐of‐merit for device performance scale nonlinearly bandgap, these semiconductors have long been known to compelling potential advantages over their narrower‐bandgap cousins high‐power RF electronics, as well deep‐UV optoelectronics, quantum...
Charge sharing between adjacent devices can lead to increased Single Event Upset (SEU) vulnerability. Key parameters affecting charge are examined, and relative collected at the hit node nodes quantified. Results show that for a twin-well CMOS process, PMOS be effectively mitigated with use of contacted guard-ring, whereas combination nodal separation, interdigitation is required mitigate NMOS effect technology studied
Design oriented criteria are developed for distributed power systems with constant loads to guarantee stability during large disturbances. The place design constraints on the input filter parameters, such as Q factor, and amount of "ideal" load that a system can support. based Lyapunov theory, mixed potential functions, existence equilibrium points. analytical validated by means computer simulations.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML"...
Because of their tolerance transformer nonidealities, resonant converters are considered to be well-suited high-voltage applications. The series and parallel topologies, as well a newly discovered hybrid topology compared for Design criteria which incorporate nonidealities developed used in the construction high voltage prototypes each topology. It is found that leads lowest peak switch current most ideal behavior.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML"...
<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> The distributions of SET pulse-widths produced by heavy ions in 130-nm and 90-nm CMOS technologies are measured experimentally using an autonomous pulse characterization technique. event cross section is the highest for pulses between 400 ps to 700 process, while it dominated range 500 900 process. increasing probability longer with scaling a key factor determining combinational logic soft errors...
Heavy ion-induced single-event burnout (SEB) is investigated in high-voltage silicon carbide power MOSFETs. Experimental data for 1200-V SiC MOSFETs show a significant decrease SEB onset voltage particle linear energy transfers greater than 10 MeV/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> /mg, above which the threshold nearly constant at half of rated maximum operating these devices. TCAD simulations parasitic bipolar junction...
Heavy-ion data suggest that a common mechanism is responsible for single-event burnout (SEB) in 1200-V power MOSFETs and junction barrier Schottky (JBS) diodes. Similarly, heavy-ion also leakage current degradation both devices. This mechanism, based on ion-induced, highly localized energy pulses, demonstrated simulations shown to be capable of causing SEB the JBS
A tutorial paper is presented on modeling and design of transformers coupled inductors. Beginning with a brief review electromagnetic laws magnetic circuit models, the electric models inductors are developed, including both magnetizing leakage effects. It shown that while voltage waveforms windings primarily related by turns ratio for devices, winding currents determined very different mechanisms. An integrated structure transformer inductor same core also discussed, as well special case...
A new on-chip single-event transient (SET) test structure has been developed to autonomously characterize the widths of random SET pulses. Simulation results show measurement granularity 900 ps for a 1.5 mum technology and also indicate that rapidly scales down with technology. Laser tests were used demonstrate circuit operation on chips fabricated using process. The experimental pulsewidths varying from about over 3 ns as laser energy was increased
A three-dimensional (3D) technology computer-aided design (TCAD) model was used to simulate charge collection at multiple nodes. Guard contacts are shown mitigate the and more quickly restore well potential, especially in PMOS devices. Mitigation of shared NMOS devices is accomplished through isolation P-wells using a triple-well option. These techniques have been partially validated heavy-ion testing three versions flip-flop shift register chains.
It is shown that the state-space averaging method can be extended by linear network theory from domain of pulse-width-modulated converters to a much larger class, including resonant switches and current-programmed mode. The canonical model concept also extended, it effect switching introduce feedback block into generalized model. These results are applied zero-current zero-voltage switches, new class nonlinear resonant-switch converters, Equivalent circuit models developed for both full...
A mathematical bit error rate (BER) model for upsets in memories protected by error-correcting codes (ECCs) and scrubbing is derived. This compared with expected upset rates sub-100-nm SRAM space environments. Because memory cells can be a critical charge (Q <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">crit</sub> ) of 1.1 fC or less, they may exhibit significantly higher than those reported earlier technologies. this, single-bit-correcting...
Three-dimensional TCAD models are used in mixed- mode simulations to analyze the effectiveness of well contacts at mitigating parasitic PNP bipolar conduction due a direct hit ion strike. 130 nm and 90 technology simulated. Results show careful contact design can improve mitigation. However, is seen decrease from simulations.
A layout technique that exploits single-event transient pulse quenching to mitigate transients in combinational logic is presented. TCAD simulations show as much 60% reduction sensitive area and 70% width for some cells.
Ion-induced degradation and catastrophic failures in high-voltage SiC junction barrier Schottky power diodes are investigated. The experimental results agree with earlier data showing discrete jumps leakage current for individual ions show that the boundary between a single-event-burnout-like effect is strong function of linear energy transfer reverse bias. TCAD simulations high localized electric fields under junction, temperatures generated directly contact, consistent hypothesis ion...
Low-energy ion-induced breakdown and single-event burnout (SEB) are experimentally observed in beta-gallium oxide ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula> -Ga2O3) Schottky diodes with voltages well below those of expected electrical breakdown. Fundamentally different responses were among alpha particle, Cf-252, heavy-ion irradiation. Technology computer-aided...
A general analytical procedure is presented for the equivalent circuit modeling of resonant converters, using series and parallel converters as examples. The switched tank elements a converter are modeled by lumped parameter circuit. element model consists, in general, discrete energy states, but may be approximated low-frequency continuous time model. These models completely characterize terminal behavior solvable any transfer function or impedance interest. With approximate it possible to...
A RHBD topology for digital phase-locked loops (DPLLs) has been developed single-event transient (SET) mitigation. By replacing the vulnerable current-based charge pump with a SET-resistant tri-state voltage-switching and low-pass filter, DPLL susceptibility was considerably reduced, while simultaneously decreasing lock-in time of DPLL. The design results in decreased area requirement minimal impacts on phase jitter power consumption. Furthermore, eliminates as most module significantly hardens
Analysis of 90 nm CMOS SET response quantifies the interaction between charge collection and redistribution in a matched-current-drive inverter chain. It is shown that pulse width difference an n-hit p-hit due to parasitic bipolar amplification on PMOS device. This exploited optimize transistor sizing n-well contact layout for RHBD combinational logic.
Heavy-ion testing of a radiation-hardened-by-design (RHBD) 90 nm dual interlocked cell (DICE latch) shows significant directional sensitivity results impacting observed cross-section and LET thresholds. 3-D TCAD simulations show this effect is due to charge sharing parasitic bipolar effects n-well potential collapse.
Simulations are used to characterize the single event transient current and voltage waveforms in deep submicron CMOS integrated circuits. Results indicate that mechanism controlling height duration of observed plateau is redistribution electrostatic potential substrate following a particle strike. Quantitative circuit technology factors influencing include restoring current, device sizing, well doping.
The effects of proton-induced displacement damage in GaN HEMTs on circuit-level RF power amplifier parameters such as circuit gain, stability, and output are presented. results explained based the device-level degradation. Commercial-off-the-shelf from two manufacturers were compared. Differences observed both device level responses. Suggestions to mitigate negative amplifiers also provided.
Ion- and terrestrial neutron-induced single-event burnout (SEB) data indicate that a thicker, more lightly doped epitaxial (epi) region significantly increases the threshold at which ion-induced SEB occurs in silicon carbide (SiC) power MOSFETs junction barrier Schottky (JBS) diodes. Simulations reduction of dissipation along core ion track is responsible for increased robustness devices have higher breakdown voltage ratings. Implications circuit design show using 3300-V MOSFET provides...
Experimental heavy-ion responses of silicon carbide (SiC) junction barrier Schottky (JBS) diodes are presented. Measured data indicate that heavy ions having range less than the epitaxial thickness do not cause degradation or catastrophic failure, even with device biased above rated breakdown voltage. also when have longer layer thickness, devices exhibit as single-event leakage current (SELC), well burnout (SEB) at biases half Device failure was observed irradiating high-energy long ranges,...