Test structures for total dose testing of SOI (silicon-on-insulator) mosfets
Simple test structures are described that are useful for optimizing the radiation hardness of, and devloping test methods for, silicon-on-insulator integrated circuits. ''Island-edge'' and edgeless n-channel transistors have been fabricated in SIMOX (Separation by Implanted Oxygen) and ZMR (Zone-Melt Recrystallized) material. The island-edge structures were formed with or without hardened sidewall isolation. By comparing the radiation results of these structures, we are able to clearly discriminate top-gate, sidewall, and back-gate parasitic leakage, all of which are very important to control in an ionizing radiation environment. With the application of -5 V substrate bias during irradiation, transistors in SIMOX and ZMR with hardened sidewalls exhibited acceptable characteristics at total doses in excess of 1.0 Mrad(Si). We have also used these test structures to compare the response of SOI transitors to Co-60 and 10-keV x-ray irradiation. We find that as expected from previous studies of oxides of similar thickness, the top-gate and sidewall insulator responses to Co-60 and 10-keV x-ray irradiation differ by less than 20 percent for the ZMR and SIMOX devices. Back-gate response, on the other hand, differed significantly for the two sources. For the SIMOX transistors, with 0.4 ..mu..m buried insulator thickness, the Co-60 irradiation induced up to a 50% overresponse (in terms of back-channel threshold voltage shifts, with O V back-gate bias applied during irradiation), relative to 10-keV x-rays. For the ZMR transistors, with 2.0 ..mu..m buried insulator thickness, the Co-60 response exceeds the x-ray response by up to a factor of 3.
- Research Organization:
- Sandia National Labs., Albuquerque, NM (USA)
- DOE Contract Number:
- AC04-76DP00789
- OSTI ID:
- 5019763
- Report Number(s):
- SAND-88-1027C; CONF-880492-1; ON: DE88008473
- Country of Publication:
- United States
- Language:
- English
Similar Records
Evaluation of silicon-on-insulator MOS (metal-oxide-semiconductor) transistor response to 10-keV x-ray and cobalt-60 irradiation
Radiation-tolerant, sidewall-hardened SOI/MOS transistors
Related Subjects
420800* -- Engineering-- Electronic Circuits & Devices-- (-1989)
DOSE RATES
ELECTRONIC CIRCUITS
HARDENING
INTEGRATED CIRCUITS
MEASURING INSTRUMENTS
MICROELECTRONIC CIRCUITS
MOS TRANSISTORS
PHYSICAL RADIATION EFFECTS
RADIATION DETECTORS
RADIATION EFFECTS
RADIATION HARDENING
SEMICONDUCTOR DETECTORS
SEMICONDUCTOR DEVICES
SI SEMICONDUCTOR DETECTORS
TESTING
TRANSISTORS