Quantitative Analysis of Trap Behaviors for Deuterium Annealing Effect on IGZO TFTs by TCAD and Experimental Characterization

초록

In this article, we investigate the effect of annealing in deuterium (D-2) ambient on the performance and reliability of InGaZnO (IGZO) thin-film transistors (TFTs). We examined the current-voltage (I-V) characteristics, as well as the ON-state current (I-on), OFF-state current (I-off), and subthreshold slope (SS) under three different conditions: after device fabrication (as-fabricated), in a deteriorated state (after 7 days), and after D-2 annealing. To analyze the reliability of IGZO TFTs, the oxygen vacancy (V-O) behavior was observed by extracting the subgap density of state (DOS) using I-V data. Quantitative and qualitative analyses of the changes in ion distribution inside the IGZO channel after D-2 annealing were performed by X-ray photoelectron spectroscopy (XPS) and secondary-ion mass spectrometry (SIMS), respectively, both of which verified the effect of the D-2 annealing. The validity of our results was further verified by comparing them to model parameters generated using a technology computer-aided design (TCAD) simulation.

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