Characteristics of field-induced-drain (FID) poly-Si TFTs with high on/off current ratio

The characteristics of polycrystalline silicon thin-film transistors (poly-Si TFTs) with a field-induction-drain (FID) structure using an inversion layer as a drain are investigated. The FID structure not only reduces the anomalous leakage current, but also maintains a high on current. An off current of 1.5 pA/ mu m and an on/off current ratio of 10/sup 7/ (V/sub d/=10, V/sub g/=-20 V) are successfully obtained. These characteristics result from good junction characteristics between the p channel and n/sup +/ inversion layer. Reducing the threshold voltage of the FID region allows a simple circuit configuration for the FID TFTs.<
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