Raymond L. Ladbury

SEE and TID Characterization of an Advanced Commercial 2Gbit NAND Flash Nonvolatile Memory

An advanced commercial 2Gbit NAND flash memory (90 nm technology, one bit/cell) has been characterized for TID and heavy ion SEE. Results are qualitatively similar to previous flash results in most respects, but we also detected a new dynamic failure mode

An Investigation of Dose Rate and Source Dependent Effects in 200 GHz SiGe HBTs

We present an investigation of the observed variations in the total dose tolerance of the emitter-base spacer and shallow trench isolation oxides in a commercial 200 GHz SiGe HBT technology. Proton, gamma, and X-ray irradiations at varying dose rates are found to produce drastically different degradation signatures at the various oxide interfaces. Extraction and analysis of the radiation-induced excess base current, as well as low-frequency noise, are used to probe the underlying physical mechanisms. Two-dimensional calibrated device simulations are employed to correlate the observed results to the spatial distributions of carrier recombination in forward- and inverse-mode operation for both pre- and post-irradiation levels. Possible explanations of our observations are offered and the implications for hardness assurance testing are discussed

Recent radiation damage and single event effect results for candidate spacecraft electronics

We present data on the vulnerability of a variety of candidate spacecraft electronics to proton and heavy ion induced single event effects and proton-induced damage. Devices tested include optoelectronics, digital, analog, linear bipolar, hybrid devices, Analog-to-Digital Converters (ADCs), Digital-to-Analog Converters (DACs), and DC-DC converters, among others.

A compendium of recent optocoupler radiation test data

We present a compendium of optocoupler radiation test data including data on neutron, proton and heavy ion displacement damage (DD), single event transients (SET) and degradation due to total ionizing dose (TID). Proton data includes ionizing and non-ionizing damage mechanisms.

Total dose performance of radiation hardened voltage regulators and references

Total dose tests of commercially available radiation hardened bipolar voltage regulators and references show reduced sensitivity to low dose rate enhancement and varying sensitivity to bias under exposure. Behavior of critical parameters in different dose rate and bias conditions is compared and the impact to hardness assurance methodology is discussed.

Radiation-induced charge collection in infrared detector arrays

A modeling approach is described for predicting charge collection in space-based infrared detector arrays due to ionizing particle radiation. The modeling uses a combination of analytical and Monte Carlo techniques to capture the essential features of energetic ion-induced charge collection to detector pixels in a two-dimensional array. The model addresses several aspects that are necessary for high-fidelity simulation of complex focal plane array structures including multiple layers, subregions within layers, variation of linear energy transfer with range, secondary electron scattering, free-field diffusion, and field-assisted diffusion. Example results are given and predictions are compared to experimental data.

Effects of Ion Atomic Number on Single-Event Gate Rupture (SEGR) Susceptibility of Power MOSFETs

The relative importance of heavy-ion interaction with the oxide, charge ionized in the epilayer, and charge ionized in the drain substrate, on the bias for SEGR failure in vertical power MOSFETs is experimentally investigated. The results indicate that both the charge ionized in the epilayer and the ion atomic number are important parameters of SEGR failure. Implications on SEGR hardness assurance are discussed.

Current single event effects results for candidate spacecraft electronics for NASA

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.

Radiation Performance of 1 Gbit DDR SDRAMs Fabricated in the 90 nm CMOS Technology Node

We present single event effect (SEE) and total ionizing dose (TID) data for 1 Gbit DDR SDRAMs (90 nm CMOS technology) as well as comparing this data with earlier technology nodes from the same manufacturer

Impact of Spacecraft Shielding on Direct Ionization Soft Error Rates for Sub-130 nm Technologies

We use ray tracing software to model various levels of spacecraft shielding complexity and energy deposition pulse height analysis to study how it affects the direct ionization soft error rate of microelectronic components in space. The analysis incorporates the galactic cosmic ray background, trapped proton, and solar heavy ion environments as well as the October 1989 and July 2000 solar particle events.