| Summary: | The ultra-short pulsed laser annealing process enhances the performance of MoS<sub>2</sub> thin film transistors (TFTs) without thermal damage on plastic substrates. However, there has been insufficient investigation into how much improvement can be brought about by the laser process. In this paper, we observed how the parameters of TFTs, i.e., mobility, subthreshold swing, I<sub>on</sub>/I<sub>off</sub> ratio, and V<sub>th</sub>, changed as the TFTs’ contacts were (1) not annealed, (2) annealed on one side, or (3) annealed on both sides. The results showed that the linear effective mobility (μ<sub>eff_lin</sub>) increased from 13.14 [cm<sup>2</sup>/Vs] (not annealed) to 18.84 (one side annealed) to 24.91 (both sides annealed). Also, I<sub>on</sub>/I<sub>off</sub> ratio increased from <inline-formula> <math display="inline"> <semantics> <mrow> <mn>2.27</mn> <mo>×</mo> <msup> <mrow> <mn>10</mn> </mrow> <mn>5</mn> </msup> </mrow> </semantics> </math> </inline-formula> (not annealed) to <inline-formula> <math display="inline"> <semantics> <mrow> <mn>3.14</mn> <mo>×</mo> <msup> <mrow> <mn>10</mn> </mrow> <mn>5</mn> </msup> </mrow> </semantics> </math> </inline-formula> (one side annealed) to <inline-formula> <math display="inline"> <semantics> <mrow> <mn>4.81</mn> <mo>×</mo> <msup> <mrow> <mn>10</mn> </mrow> <mn>5</mn> </msup> <mo> </mo> </mrow> </semantics> </math> </inline-formula>(both sides annealed), with V<sub>th</sub> shifting to negative direction. Analyzing the main reason for the improvement through the Y function method (YFM), we found that both the contact resistance (R<sub>c</sub>) and the channel interface resistance (R<sub>ch</sub>) improves after the pulsed laser annealings under different conditions. Moreover, the R<sub>c</sub> enhances more dramatically than the R<sub>ch</sub> does. In conclusion, our picosecond laser annealing improves the performance of TFTs (especially, the R<sub>c</sub>) in direct proportion to the number of annealings applied. The results will contribute to the investigation about correlations between the laser annealing process and the performance of devices.
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