Radiation effects at low electric fields in thermal, SIMOX, and bipolar-based oxides

Journal Article · Sun Dec 01 04:00:00 EST 1996 · IEEE Transactions on Nuclear Science

DOI:https://doi.org/10.1109/23.556834· OSTI ID:443020

Fleetwood, D M; Riewe, L C; Schwank, J R ^[1]; Witczak, S C; Schrimpf, R D ^[2]

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1. Sandia National Labs., Albuquerque, NM (United States)
2. Univ. of Arizona, Tucson, AZ (United States). Dept. of Electrical and Computer Engineering

The authors have performed thermally-stimulated-current (TSC) and capacitance-voltage measurements on 370--1,080 nm thermal, SIMOX, and bipolar-base oxides as functions of bias, dose rate, and temperature during irradiation. Base oxides built in a development version of Analog Devices` RF25 process show much more interface-trap buildup than XFCB oxides. Both net-oxide-trap and interface-trap charge densities for RF25 capacitors are enhanced significantly during low-dose-rate or high-temperature irradiation at 0 V over high-rate, 25 C exposures. TSC measurements show the increase in net-oxide-trap charge density is due to a decrease in trapped electron density with decreasing dose rate or increasing irradiation temperature (at least to 125 C), and not by increased trapped hole density. Similar enhancement of net-oxide-trap and interface-trap charge density with decreasing dose rate is found for soft thermal oxides irradiated at 0 V, but not 5 V. These results strongly suggest that space charge effects associated with holes metastably trapped in the bulk of the oxide can cause the enhanced bipolar gain degradation seen at low dose rates and/or high temperatures in many technologies. No enhanced radiation-induced charge trapping is observed for low-dose-rate or high-temperature, 0 V irradiation of SIMOX capacitors. Implications for hardness assurance tests are discussed.

• Research Organization: Sandia National Laboratory
• DOE Contract Number: AC04-94AL85000
• OSTI ID: 443020
• Report Number(s): CONF-960773--
• Journal Information: IEEE Transactions on Nuclear Science, Journal Name: IEEE Transactions on Nuclear Science Journal Issue: 6 Vol. 43; ISSN IETNAE; ISSN 0018-9499
• Country of Publication: United States
• Language: English

Related Subjects

44 INSTRUMENTATION
INCLUDING NUCLEAR AND PARTICLE DETECTORS
ELECTRICAL PROPERTIES
PHYSICAL RADIATION EFFECTS
RADIATION DOSES
SEMICONDUCTOR DEVICES
SPACE CHARGE
TEMPERATURE DEPENDENCE
TRAPPING