School of Electrical, Computer and Energy Engineering
PhD Final Oral Defense
Total Dose Simulation for High Reliability Electronics
by
Garrett Schlenvogt
April 4th, 2014
10:00 am
ENGRC 490
Committee:
Dr. Hugh Barnaby, Chair
Dr. Stephen Goodnick
Dr. Dragica Vasileska
Dr. Keith Holbert
Abstract
New technologies enable the exploration of space, high-fidelity defense systems,
lighting fast intercontinental communication systems as well as medical technologies that
extend and improve patient lives. The basis for these technologies is high reliability
electronics devised to meet stringent design goals and to operate consistently for many
years deployed in the field.
An on-going concern for engineers is the consequences of ionizing radiation
exposure, specifically total dose effects. For many of the different applications, there is a
likelihood of exposure to radiation, which can result in device degradation and potentially
failure. While the total dose effects and the resulting degradation are a well-studied field,
and methodologies to help mitigate degradation have been developed, there is still a need
for simulation techniques to help designers understand total dose effects within their
design.
To that goal, the work presented here details simulation techniques to analyze as
well as predict the total dose response of a circuit. In this dissertation the total dose
effects are broken into two sub-categories, intra-device and inter-device effects in CMOS
technology. Intra-device effects degrade the as-indented performance of both n-channel
and p-channel transistors, while inter-device effects result in loss of device isolation. In
this work, multiple case studies are presented for which total dose degradation is of
concern. Through the simulation techniques, the individual device and circuit responses
are modeled post-irradiation. Application of these simulation techniques by circuit
designers allow predictive simulation of total dose effects, allowing focused design
changes to be implemented to increase radiation tolerance of high reliability electronics.