Enhanced Subthreshold Characteristics and Operational Stability in Metal-Oxide Thin-Film Transistors Using IGZO-Capped Bilayer Channels

초록

In this paper, we report improved sub-threshold characteristics and operational stability using indium gallium zinc oxide (IGZO)-capped bilayer channel structures for solution-processed metal-oxide thin-film transistors (TFTs). By adopting the IGZO-capped bilayer channel structures (indium oxide (InOx)/IGZO, and indium strontium oxide (ISO)/IGZO), we could obtain metal-oxide TFTs with a steep sub-threshold slope, near zero-volt threshold voltage, and enhanced field-effect mobility and operational stability via a low-temperature photochemical activation process. We found that by using the bilayer channels, we could reduce the maximum bulk trap density of the channels from 5.72 x 10(17)/eV-cm(3) to 6.14 x 10(16)/eV-cm(3) and from 1.96 x 10(17)/eV-cm(3) to 9.64 x 10(16)/eV-cm(3) for InOx and ISO channels, respectively. In addition, we also improved the operational stability under a positive gate-bias stress, by using the bilayer channels. From these results, we can conclude that the IGZO-capped bilayer channel structure can offer the realization of high performance and stable metal-oxide TFTs fabricated via solution processing.

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