Loading…
Electron beam irradiation effects in thick-oxide MOS capacitors
MOS capacitors were fabricated on n-type 〈111〉 silicon wafers with aluminum contacts. The oxide thickness ranged from 1000Å to 12,000Å. These capacitors were irradiated with an electron beam at doses of 10 11 to 10 17 electrons/cm 2 and energies of 5 kV and 15 kV. C-V measurements were made to chara...
Saved in:
Published in: | IEEE transactions on nuclear science 1974-08, Vol.21 (4), p.14-19 |
---|---|
Main Authors: | , , , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that cite this one |
Online Access: | Get full text |
Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
Summary: | MOS capacitors were fabricated on n-type 〈111〉 silicon wafers with aluminum contacts. The oxide thickness ranged from 1000Å to 12,000Å. These capacitors were irradiated with an electron beam at doses of 10 11 to 10 17 electrons/cm 2 and energies of 5 kV and 15 kV. C-V measurements were made to characterize the effects of irradiation. In the thin oxide samples and in the thick oxide samples at 15 kV, the C-V curves revealed a positive fixed charge accumulation in the oxide at dose levels above 1013 electrons/cm 2 . In the thicker oxide samples at 5 kV there was evidence of negative charge trapping at the lower dose levels changing to positive at the highest dose. In all cases, there was a reversal in the sense of the hysteresis effects in the C-V curves above 10 15 electrons/cm 2 , implying slow surface states which could follow the dc bias voltage but not the ac test signal. There was also a marked increase in the magnitude of the turn-on voltage for strong inversion implying an increase in fast surface states or lateral ionic charge nonuniformities. |
---|---|
ISSN: | 0018-9499 1558-1578 |
DOI: | 10.1109/TNS.1974.6499261 |