The device degradation of polycrystalline-silicon thin-film transistors stressed with different gate pulse waveforms is investigated. It is first observed that the degradation is dependent on the rising time of the gate pulses for the gate voltage swing below the threshold voltage. The degradation ratio of the mobility is analyzed with respect to two factors, namely, the magnitude of the lateral transient electric field and the change in the numbers of the carrier near the edges of the channel. A new index considering these two factors is proposed to depict the device degradation. It shows good linearity between the degradation in mobility and the proposed index.
- AC stress
- Dynamic stress
- Poly-Si thin-film transistors (TFTs)