Electrical Instability of Hydrogenated Amorphous Silicon Thin-Film Transistors for Active-Matrix Liquid-Crystal Displays
- 1 September 1998
- journal article
- Published by IOP Publishing in Japanese Journal of Applied Physics
- Vol. 37 (9R) , 4704-4710
- https://doi.org/10.1143/jjap.37.4704
Abstract
We investigated the threshold voltage shifts (ΔV T) of inverted-staggered hydrogenated amorphous silicon (a-Si:H) thin-film transistors (TFTs) induced by steady-state (dc) and pulsed (ac) gate bias-temperature-stress (BTS) conditions. Our study showed that, for an equivalent effective-stress-time, ΔV T has an apparent pulse-width dependence under negative BTS conditions–the narrower the pulse width, the smaller the ΔV T. This gate-bias pulse-width dependence is explained by an effective-carrier-concentration model, which relates ΔV T for negative pulsed gate-bias stress to the concentration of mobile carriers accumulated in the conduction channel along the a-Si:H/gate insulator interface. In addition, our investigation of the methodology of a-Si:H TFT electrical reliability evaluation indicates that, instead of steady-state BTS, pulsed BTS should be used to build the database needed to extrapolate ΔV T induced by a long-term display operation. Using these experimental results, we have shown that a-Si:H TFTs have a satisfactory electrical reliability for a long-term active-matrix liquid-crystal display (AMLCD) operation.Keywords
This publication has 11 references indexed in Scilit:
- Bias-stress-induced stretched-exponential time dependence of charge injection and trapping in amorphous thin-film transistorsApplied Physics Letters, 1993
- Defect pool in amorphous-silicon thin-film transistorsPhysical Review B, 1992
- Threshold Voltage Shift of Amorphous Silicon Thin-Film Transistors During Pulse OperationJapanese Journal of Applied Physics, 1991
- Characterization of instability in amorphous silicon thin-film transistorsJournal of Applied Physics, 1991
- Threshold voltage instability of a-Si:H TFTs in liquid crystal displaysJournal of Non-Crystalline Solids, 1989
- Time and temperature dependence of instability mechanisms in amorphous silicon thin-film transistorsApplied Physics Letters, 1989
- Bias dependence of instability mechanisms in amorphous silicon thin-film transistorsApplied Physics Letters, 1987
- Creation of near-interface defects in hydrogenated amorphous silicon-silicon nitride heterojunctions: The role of hydrogenPhysical Review B, 1987
- Resolution of amorphous silicon thin-film transistor instability mechanisms using ambipolar transistorsApplied Physics Letters, 1987
- Instability mechanism in hydrogenated amorphous silicon thin-film transistorsApplied Physics Letters, 1987