Abstract
A novel defect passivation process in polycrystalline silicon (poly-Si) thin-film transistors (TFTs) utilizing nitrous oxide (N2O) plasma has been performed to significantly improve the electrical characteristics of poly-Si TFTs. For example, the on/off current ratio increased to 6.58 × 106; the threshold voltage decreased to 0.55 V, and the field effect mobility increased to 48.2 cm2/Vs. The distribution of N incorporated in this oxide and these poly-Si films was examined by means of secondary ion mass spectroscopy (SIMS) and Auger electron spectroscopy (AES). It is believed that the nitrogen radicals which dissociated from the N2O gas as well as the hydrogen radicals which dissociated from the residual H2O can both diffuse into the active poly-Si layer to passivate the grain-boundary defect states and accumulate at the gate SiO2/poly-Si interface to reduce the interface state density. Thus, the hot-carrier reliability of TFTs was also enhanced after the N2O plasma treatments.
Original language | English |
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Pages (from-to) | 2028-2031 |
Number of pages | 4 |
Journal | Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers |
Volume | 36 |
Issue number | 4 A |
DOIs | |
State | Published - 1 Apr 1997 |
Keywords
- Defect passivation
- Hot-carrier reliability
- NO plasma
- Polycrystalline silicon
- Thin-film transistor