Jerry L. Wert

HBD layout isolation techniques for multiple node charge collection mitigation

A three-dimensional (3D) technology computer-aided design (TCAD) model was used to simulate charge collection at multiple nodes. Guard contacts are shown to mitigate the charge collection and to more quickly restore the well potential, especially in PMOS devices. Mitigation of the shared charge collection in NMOS devices is accomplished through isolation of the P-wells using a triple-well option. These techniques have been partially validated through heavy-ion testing of three versions of flip-flop shift register chains.

Neutron-induced single event burnout in high voltage electronics

Energetic neutrons with an atmospheric neutron spectrum, which were demonstrated to induce single event burnout in power MOSFETs, have been shown to induce burnout in high voltage (>3000 V) electronics when operated at voltages as low as 50% of rated voltage. The laboratory failure rates correlate well with field failure rates measured in Europe.

First Nondestructive Measurements of Power MOSFET Single Event Burnout Cross Sections

A new technique to nondestructively measure single event burnout cross sections for N-channel power MOSFETs is presented. Previous measurements of power MOSFET burnout susceptibility have been destructive and thus not conducive to providing statistically meaningful burnout probabilities. The nondestructive technique and data for various device types taken at several accelerators, including the LBL Bevalac, are documented. Several new phenomena are observed.

Single event upset and charge collection measurements using high energy protons and neutrons

RAMs, microcontrollers and surface barrier detectors were exposed to beams of high energy protons and neutrons to measure the induced number of upsets as well as energy deposition. The WNR facility at Los Alamos provided a neutron spectrum similar to that of the atmospheric neutrons. Its effect on devices was compared to that of protons with energies of 200, 400, 500 and 800 MeV. Measurements indicate that SEU cross sections for 400 MeV protons are similar to those induced by the atmospheric neutron spectrum. >

First observations of power MOSFET burnout with high energy neutrons

Single event burnout was seen in power MOSFETs exposed to high energy neutrons. Devices with rated voltage /spl ges/400 volts exhibited burnout at substantially less than the rated voltage. Tests with high energy protons gave similar results. Burnout was also seen in limited tests with lower energy protons and neutrons. Correlations with heavy-ion data are discussed. Accelerator proton data gave favorable comparisons with burnout rates measured on the APEX spacecraft. Implications for burnout at lower altitudes are also discussed.

Propagating SET Characterization Technique for Digital CMOS Libraries

A circuit architecture based on simple logic gates is described which uses small chip areas and low speed testing to characterize single event transients for digital applications. Utility of this architecture is demonstrated with heavy ion data on a 130 nm library

Enhanced TID Susceptibility in Sub-100 nm Bulk CMOS I/O Transistors and Circuits

This paper evaluates the radiation responses of 2.5 V I/O transistors and regular-threshold MOSFETs from a 90 nm commercial bulk CMOS technology. The data obtained from Co ionizing radiation experiments indicate enhanced TID susceptibility in I/O devices and circuits, which is attributed to the p-type body doping. A quantitative model is used to analyze the effects of doping and oxide trapped charge buildup along the sidewall of the shallow trench isolation oxide. These effects are captured in the general electrostatic equation for surface potential, which can be correlated to off-state leakage current. Device simulations are used in concert with experimental measurements and the analytical model to provide physical insight into the radiation response of each device type.

Heavy Ion, High-Energy, and Low-Energy Proton SEE Sensitivity of 90-nm RHBD SRAMs

We measure the sensitivity of different 90-nm SRAM cells to single-event upsets (SEUs) caused by heavy ions, high energy protons, and low energy protons. We discuss radiation hardened by design techniques that impact SEU sensitivity.

Measurement of SEU Thresholds and Cross Sections at Fixed Incidence Angles

Current SEU testing and analysis techniques have as basic assumptions that the charge deposited at a junction depends linearly on the linear energy transfer (LET) of the ion and the pathlength of the ion through an imagined parallelepiped that represents the depletion region. This study tests these assumptions for two bipolar parts, AMD 27LSOO and Fairchild 93L422, by irradiating at fixed angles while varying the LET of two ion species. It was found that the 27LSOO shows a pronounced ion species dependence, and may show a deviation of deposited charge from the usual inverse-cosine times a fixed depletion depth, while the 93L422 exhibited the expected inverse-cosine dependence and no ion species dependence.

Angular Dependence of Single Event Sensitivity in Hardened Flip/Flop Designs

SEU data on 90 nm structures displays a strong dependence on incident angle. A right parallelepiped (RPP) approximation is clearly not applicable to the observed response. This paper presents the data, possible mechanisms, and implications for testing and error rate predictions.