Electrical characteristics of ultra-thin gate oxides (<3 nm) prepared by direct current superimposed with alternating-current anodization
Abstract
Ultra-thin gate oxides with thickness smaller than 3 nm were prepared by anodic oxidation (anodization) in deionized water under direct-current biasing superimposed with alternating-current signal (DAC-ANO). It is experimentally observed that the DAC-ANO oxides after suitable high temperature annealing have better electrical characteristics than conventional rapid thermal oxides (RTO). Other advantages of DAC-ANO oxides include lower leakage current, higher time-zero dielectric breakdown and time-dependent dielectric breakdown endurance, and less stress-induced leakage current. The charge trapping behavior under high field stress is less significant in DAC-ANO oxides than in RTO ones. The improved reliability of DAC-ANO oxides can be explained by the nature of AC switching effect. DAC-ANO oxide is a potential candidate in the application of ultra-thin gate oxide to deep sub-micron devices.
- Publication:
-
Solid State Electronics
- Pub Date:
- January 2004
- DOI:
- 10.1016/S0038-1101(03)00257-0
- Bibcode:
- 2004SSEle..48...23C