TY - GEN
T1 - Two-stage model for lifetime prediction of highly stable amorphous-silicon thin-film transistors under low-gate field
AU - Liu, Ting
AU - Wagner, Sigurd
AU - Sturm, James C.
PY - 2012/10/5
Y1 - 2012/10/5
N2 - Highly stable a-Si TFTs reported recently with extremely long operating lifetimes under DC gate bias are attractive for analog drivers of the OLEDs in AMOLED displays [1]. At room temperature, the time for the DC saturation current to drop to 50% is predicted to be 100 to 1,000 years. However, the lifetimes were extrapolated with a stretched-exponential model for defect creation in a-Si, based on only month-long room temperature tests. In this study, we present a two-stage threshold voltage shift model for lifetime prediction from temperature dependent measurements. We find that (i) a unified stretched exponential fit models the drain current degradation from 60°C to 140°; and (ii) there is a second instability mechanism that initially dominates up to hours or days at low temperatures, so that tests conducted only at room temperature may not predict lifetime accurately.
AB - Highly stable a-Si TFTs reported recently with extremely long operating lifetimes under DC gate bias are attractive for analog drivers of the OLEDs in AMOLED displays [1]. At room temperature, the time for the DC saturation current to drop to 50% is predicted to be 100 to 1,000 years. However, the lifetimes were extrapolated with a stretched-exponential model for defect creation in a-Si, based on only month-long room temperature tests. In this study, we present a two-stage threshold voltage shift model for lifetime prediction from temperature dependent measurements. We find that (i) a unified stretched exponential fit models the drain current degradation from 60°C to 140°; and (ii) there is a second instability mechanism that initially dominates up to hours or days at low temperatures, so that tests conducted only at room temperature may not predict lifetime accurately.
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U2 - 10.1109/DRC.2012.6257025
DO - 10.1109/DRC.2012.6257025
M3 - Conference contribution
AN - SCOPUS:84866942606
SN - 9781467311618
T3 - Device Research Conference - Conference Digest, DRC
SP - 245
EP - 246
BT - 70th Device Research Conference, DRC 2012 - Conference Digest
T2 - 70th Device Research Conference, DRC 2012
Y2 - 18 June 2012 through 20 June 2012
ER -