Engineering topics

Thorbourn, D. O.

Publications and source records attributed to Thorbourn, D. O..

3 records

NASA NTRS2020

In-Situ Testing Methods for Mixed-Mode Harsh Environments

Future NASA missions are driving a need for instrumentation and space electronics that will operate at extreme temperatures, with low mass and extended deployments. This need results in devices that will experience dose damage at both low and high temperatures that will suppress annealing and induce accelerated wear out issues. Therefore, the ability to perform radiation tests on devices at temperature is critical. This paper analyses the methods and process to enable these test as developed at the JPL Dynamitron Facility. Since electronics are the radiation source for this facility, the steps to ensure parity with cobalt-60 testing are discussed. Also discussed are the implications for system level testing and mixed radiation mode testing for highly integrated and scaled devices.

Scheick, Leif Z↗

NASA NTRS2013

Charge Yield at Low Electric Fields: Considerations for Bipolar Integrated Circuits

A significant reduction in total dose damage is observed when bipolar integrated circuits are irradiated at low temperature. This can be partially explained by the Onsager theory of recombination, which predicts a strong temperature dependence for charge yield under low-field conditions. Reduced damage occurs for biased as well as unbiased devices because the weak fringing field in thick bipolar oxides only affects charge yield near the Si/SiO2 interface, a relatively small fraction of the total oxide thickness. Lowering the temperature of bipolar ICs - either continuously, or for time periods when they are exposed to high radiation levels - provides an additional degree of freedom to improve total dose performance of bipolar circuits, particularly in space applications.

ionizing radiation↗

NASA NTRS2012

Total Dose Effects on Bipolar Integrated Circuits at Low Temperature

Total dose damage in bipolar integrated circuits is investigated at low temperature, along with the temperature dependence of the electrical parameters of internal transistors. Bandgap narrowing causes the gain of npn transistors to decrease far more at low temperature compared to pnp transistors, due to the large difference in emitter doping concentration. When irradiations are done at temperatures of -140 deg C, no damage occurs until devices are warmed to temperatures above -50 deg C. After warm-up, subsequent cooling shows that damage is then present at low temperature. This can be explained by the very strong temperature dependence of dispersive transport in the continuous-time-random-walk model for hole transport. For linear integrated circuits, low temperature operation is affected by the strong temperature dependence of npn transistors along with the higher sensitivity of lateral and substrate pnp transistors to radiation damage.

linear integrated circuits↗