Improved electrical performance of a sol–gel IGZO transistor with high-k Al2O3 gate dielectric achieved by post annealing

Published on 2019-07-22T03:27:35Z (GMT) by
Abstract We have explored the effect of post-annealing on the electrical properties of an indium gallium zinc oxide (IGZO) transistor with an Al2O3 bottom gate dielectric, formed by a sol–gel process. The post-annealed IGZO device demonstrated improved electrical performance in terms of threshold variation, on/off ratio, subthreshold swing, and mobility compared to the non-annealed reference device. Capacitance–voltage measurement confirmed that annealing can lead to enhanced capacitance properties due to reduced charge trapping. Depth profile analysis using X-ray photoelectron spectroscopy proved that percentage of both the oxygen vacancy (VO) and the hydroxyl groups (M–OH) within the IGZO/Al2O3 layers, which serve as a charge trapping source, can be substantially reduced by annealing the fabricated transistor device. Furthermore, the undesired degradation of the contact interface between source/drain electrode and the channel, which mainly concerns VO, can be largely prevented by post-annealing. Thus, the facile annealing process also improves the electrical bias stress stability. This simple post annealing approach provides a strategy for realising better performance and reliability of the solid sol–gel oxide transistor.

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Lee, Esther; Kim, Tae; Lee, Seung; Kim, Jee; Kim, Jaeun; Jeong, Tae; et al. (2019): Improved electrical performance of a sol–gel IGZO transistor with high-k Al2O3 gate dielectric achieved by post annealing. figshare. Collection. https://doi.org/10.6084/m9.figshare.c.4584146.v1