Publications

Abstract not provided.

Abstract not provided.

Abstract not provided.

This paper investigates the effects of high dose rate ionizing radiation and total ionizing dose (TID) on tantalum oxide (TaOx) memristors. Transient data were obtained during the pulsed exposures for dose rates ranging from approximately 5.0 × 107rad(Si)/s to 4.7 × 108rad(Si)/s and for pulse widths ranging from 50 ns to 50 μs. The cumulative dose in these tests did not appear to impact the observed dose rate response. Static dose rate upset tests were also performed at a dose rate of ∼3.0 × 108rad(Si)/s. This is the first dose rate study on any type of memristive memory technology. In addition to assessing the tolerance of TaOx memristors to high dose rate ionizing radiation, we also evaluated their susceptibility to TID. The data indicate that it is possible for the devices to switch from a high resistance off-state to a low resistance on-state in both dose rate and TID environments. The observed radiation-induced switching is dependent on the irradiation conditions and bias configuration. Furthermore, the dose rate or ionizing dose level at which a device switches resistance states varies from device to device; the enhanced susceptibility observed in some devices is still under investigation. Numerical simulations are used to qualitatively capture the observed transient radiation response and provide insight into the physics of the induced current/voltages.

The locations of conductive regions in TaOx memristors are spatially mapped using a microbeam and Nanoimplanter by rastering an ion beam across each device while monitoring its resistance. Microbeam irradiation with 800 keV Si ions revealed multiple sensitive regions along the edges of the bottom electrode. The rest of the active device area was found to be insensitive to the ion beam. Nanoimplanter irradiation with 200 keV Si ions demonstrated the ability to more accurately map the size of a sensitive area with a beam spot size of 40 nm by 40 nm. Isolated single spot sensitive regions and a larger sensitive region that extends approximately 300 nm were observed.

Abstract not provided.

Abstract not provided.

In this report, measurements of the prompt radiation-induced conductivity (RIC) in 3 mil samples of Pyralux® are presented as a function of dose rate, pulse width, and applied bias. The experiments were conducted with the Medusa linear accelerator (LINAC) located at the Little Mountain Test Facility (LMTF) near Ogden, UT. The nominal electron energy for the LINAC is 20 MeV. Prompt conduction current data were obtained for dose rates ranging from ~2 x 10⁹ rad(Si)/s to ~1.1 x 10¹¹ rad(Si)/s and for nominal pulse widths of 50 ns and 500 ns. At a given dose rate, the applied bias across the samples was stepped between -1500 V and 1500 V. Calculated values of the prompt RIC varied between 1.39x10^-8 Ω^-1 · m^-1 and 2.67x10^-7 Ω^-1 · m^-1 and the prompt RIC coefficient varied between 1.25x10^-18 Ω^-1 · m^-1/(rad/s) and 1.93x10^-17 Ω^-1 · m^-1/(rad/s).

Abstract not provided.

Abstract not provided.

Abstract not provided.

Abstract not provided.

Abstract not provided.

Abstract not provided.

Abstract not provided.

Abstract not provided.

Abstract not provided.

Abstract not provided.

Abstract not provided.

Abstract not provided.

Abstract not provided.

Low dose rate experiments on field-oxide-field-effect-transistors (FOXFETs) fabricated in a 90 nm CMOS technology indicate that there is a dose rate enhancement factor (EF) associated with radiation-induced degradation. One dimensional (1-D) numerical calculations are used to investigate the key mechanisms responsible for the dose rate dependent buildup of radiation-induced defects in shallow trench isolation (STI) oxides. Calculations of damage EF indicate that oxide thickness, distribution of hole traps and hole capture cross-section affect dose rate sensitivity. The dose rate sensitivity of STI oxides is compared with the sensitivity of bipolar base oxides using model calculations. © 2011 IEEE.