Polyoxides grown on n/sup +/ polysilicon

Shye Lin Wu, Chun Yuan Chen, Ta Yow Lin, Chung Len Lee, Tan Fu Lei, Mong Song Liang
1997 IEEE Transactions on Electron Devices  
The polarity asymmetry on the electrical characteristics of the oxides grown on n + polysilicon (polyoxides) was investigated in terms of the oxidation process, the doping level of the lower polysilicon layer, the oxidation temperature and the oxide thickness. It was found that the thin polyoxide prepared by using a low-temperature wafer loading and N2 preannealing process, has a smoother polyoxide/polysilicon interface and exhibits a lower oxide tunneling current, a higher dielectric breakdown
more » ... ielectric breakdown field when the top electrode is positively biased, a lower electron trapping rate and a larger charge-to-breakdown than does the normal polyoxide. The polarity asymmetry is also strongly dependent on the doping level of the lower polysilicon layer, the oxidation temperature and the oxide thickness. It was found that only the thinner polyoxides (240Å) grown on the heavily-doped polysilicon film (30 /sq) by using the highertemperature oxidation process (950 C) conduct a less oxide tunneling current when the top electrode is positively biased.
doi:10.1109/16.554805 fatcat:qkvexqhxarfedarirdq7xytvue