| 摘要 |
PURPOSE:To precisely and easily evaluate the estimated life of a TFT which is used at a desired constant gate voltage and constant temperature by evaluating the estimated life thereof by a specific formula by using a time coefficient, boltage coefficient and temperature coefficient which are determined on the basis of a-BT stress test and respective specific formulae. CONSTITUTION:Based on the relationship between a thershold voltage shift quantity DELTAVth and the time t obtained from a-BT stress test, a time factor alphais determined Eq. (I). In addition, based on the relationship between a threshold voltage shift quantity DELTAVth and a gate voltage Vc which are obtained from a-BT stress test by using a different gate voltage Vc, a voltage coefficient (d) in Eq. (II) is determined. Further, based on the relationship between a threshold voltage shift quantity DELTAVth and the temperature T obtained from a-BT stress test which is conducted at a different temperature T, a temperature coefficient phi0 is determined in Eq. (III). As a result, a proportional constant c2 is determined in Eq. (IV) by using the obtained time factor alpha, voltage coefficient d and temperature coefficient phi0, and finally the life of an TFT is calculated from Eq. (V). |
