Search NASA⌕ Search

Engineering topics

Aguirre, Brandon Adrian

Publications and source records attributed to Aguirre, Brandon Adrian.

At least 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Response of GaN-Based Semiconductor Devices to Ion and Gamma Irradiation

GaN has electronic properties that make it an excellent material for the next generation of power electronics; however, its radiation hardening still needs further understanding before it is used in radiation environments. In this work we explored the response of commercial InGaN LEDs to two different radiation environments: ion and gamma irradiations. For ion irradiations we performed two types of irradiations at the Ion Beam Lab (IBL) at Sandia National Laboratories (SNL): high energy and end of range (EOR) irradiations. For gamma irradiations we fielded devices at the gamma irradiation facility (GIF) at SNL. The response of the LEDs to radiation was investigated by IV, light output and light output vs frequency measurements. We found that dose levels up to 500 krads do not degrade the electrical properties of the devices and that devices exposed to ion irradiations exhibit a linear and non- linear dependence with fluence for two different ranges of fluence levels. We also performed current injection annealing studies to explore the annealing properties of InGaN LEDs.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2019

Sandia National Laboratories (FY19 Progress Report)

The Energetic Neutrons campaign led by Sandia National Laboratories (SNL) had a successful year testing electronic devices under 14 MeV neutron irradiation at OMEGA. During FY19 SNL employees were trained to take over new responsibilities while visiting LLE, continued collaborating with external organizations and generated knowledge that supports SNL's National Security mission.

99 GENERAL AND MISCELLANEOUS↗
DOE OSTI2018

Superlattice-enhanced silicon soft X-ray and charged particle detectors with nanosecond time response

Here, silicon detectors are an essential measurement tool for Inertial Confinement Fusion and High-Energy-Density Physics Applications, where temporal response of the order of nanoseconds is essential. Soft X-rays (<1 keV), Ultraviolet light, and low-energy electrons (<10 keV) can provide essential information in diagnosing rapidly changing plasma conditions, but reducing the detector dead layer is essential to improving detector response for these shallowly absorbed particles. This paper details a study of silicon detector surface preparation methods such as ion implant parameters, and the addition of a quantum 2D superlattice, to produce fast detectors that are highly sensitive to shallowly absorbed radiation. Measurements of visible light quantum efficiency, electron responsivity, and pulsed x-ray response indicate that detectors with a 2-layer superlattice enjoy a significant benefit over equivalent detectors using an ion implant at the illuminated surface.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2018

Analysis of the IBL and LBNL irradiated PIN and PN diodes

This report is a follow-up to the previous report on the difference between high fluence, high and low flux irradiations. There was a discrepancy in the data for the LBNL irradiated S5821 PIN diodes. There were diodes irradiated in the two batches (high and low flux) with the same flux and fluence for reference (lell ions/cm 2 /shot and 5, 10, and 20 ions/cm 2 total flux). Although these diodes should have the same electrical characteristics their leakage currents were different by a factor of 5-6 (batch 2 was larger). Also, the C-V measurements showed drastically different results. It was speculated that these discrepancies were due to one of the following two reasons: 1. Different times elapsed between radiation and characterization. 2. Different areas were irradiated (roughly half of the diodes were covered during irradiation). To address the first concern, we annealed the devices according to the ASTM standard [1]. The differences remained the same. To determine the irradiated area, we performed large area IBIC scans on several devices. Error! Reference source not found. below shows the IBIC maps of two devices one from each batch. The irradiated areas are approximately the same.

42 ENGINEERING↗
DOE OSTI2017

Stochastic Gain Degradation in III-V Heterojunction Bipolar Transistors due to Single Particle Displacement Damage

As device dimensions decrease single displacement effects are becoming more important. We measured the gain degradation in III-V Heterojunction Bipolar Transistors due to single particles using a heavy ion microbeam. Two devices with different sizes were irradiated with various ion species ranging from oxygen to gold to study the effect of the irradiation ion mass on the gain change. From the single steps in the inverse gain (which is proportional to the number of defects) we calculated Cumulative Distribution Functions to help determine design margins. The displacement process was modeled using the Marlowe Binary Collision Approximation (BCA) code. The entire structure of the device was modeled and the defects in the base-emitter junction were counted to be compared to the experimental results. While we found good agreement for the large device, we had to modify our model to reach reasonable agreement for the small device.

42 ENGINEERING↗
DOE OSTI2016

Comparison of gain degradation and deep level transient spectroscopy in pnp Si bipolar junction transistors irradiated with different ion species

Here, we studied the effect of light ion and heavy ion irradiations on pnp Si BJTs. A mismatch in DLTS deep peak amplitude for devices with same final gain but irradiated with different ion species was observed. Also, different ions cause different gain degradation when the DLTS spectra are matched. Pre-dosed ion-irradiated samples show that ion induced ionization does not account for the differences in DLTS peak height but isochronal annealing studies suggest that light ions produce more VP defects than heavy ions to compensate for the lack of clusters that heavy ions produce. The creation of defect clusters by heavy ions is evident by the higher content of E4 and V* 2 defects compared to light ions.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗