Radiation-enhanced short channel effects due to multi-dimensional influence from charge at trench isolation oxides
Radiation enhanced drain induced barrier lowering (DIBL) was experimentally observed and verified by 3-D simulations for submicron devices with trench isolation oxides. Submicron MOSFETs with shallow trench isolation were exposed to total-ionizing-dose radiation. Prior to irradiation, the devices exhibited near-ideal current-voltage characteristics, with no significant short-channel effects for as-drawn gate lengths of 0.4 {micro}m. Following irradiation, the off-state leakage current increased significantly for total doses above about 650 krad(SiO{sub 2}). In addition, the irradiated devices exhibited DIBL that increased the drain current by 5--10x for a gate length of 0.4 {micro}m (the nominal minimum gate length for this process) and much more for slightly shorter devices (0.35 {micro}m). The increase in the off-state leakage current and the accompanying DIBL are shown to be associated with a parasitic field-effect transistor that is present at the edge of the shallow trench. Three-dimensional simulations are used to illustrate the effect. Simulations show that trapped charge at the trench sidewalls enhance the DIBL by depleting the edges of the channel. Radiation-induced charge may decrease the effectiveness of short-channel engineering.
- Research Organization:
- Vanderbilt Univ., Nashville, TN (US)
- Sponsoring Organization:
- Defense Threat Reduction Agency
- OSTI ID:
- 20014748
- Journal Information:
- IEEE Transactions on Nuclear Science (Institute of Electrical and Electronics Engineers), Journal Name: IEEE Transactions on Nuclear Science (Institute of Electrical and Electronics Engineers) Journal Issue: 6Pt1 Vol. 46; ISSN 0018-9499; ISSN IETNAE
- Country of Publication:
- United States
- Language:
- English
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