Improved reliability for gate dielectric of low-temperature polysilicon thin-film transistors by NO-plasma nitridation

Low-temperature polysilicon thin-film transistors (poly-Si TFTs) fabricated under 600degreesC are treated with nitridation using NO plasma. Samples with nitrided gate oxide, nitrided active polysilicon, or both layers nitrided are produced respectively to compare their reliability. It is found that all the nitrided devices demonstrate improved reliability over the control one under both high-field and hot-carrier stresses. Moreover, nitridation on the oxide produces better results under high-field stress while nitridation on the polysilicon is better under hot-carrier stress. The effectiveness of this low-temperature plasma. nitridation on TFTs makes the process potentially applicable to the production of high-quality flat-panel displays on glass substrate. (C) 2003 Elsevier Science Ltd. All rights reserved.