Bilayered Etch-Stop Layer of Al2O3/SiO2 for High-Mobility In-Ga-Zn-O Thin-Film Transistors

Abstract

We proposed a bilayered etch-stop layer (BiESL) composed of Al2O3/SiO2 for the high-mobility oxide thin-film transistor (TFT) fabricated with low-resistivity Cu electrodes. The In-Ga-Zn-O TFT employing the BiESL showed no marked degradation in its high mobility and transfer characteristics even after the conventional passivation process using SiNx film, which causes hydrogen incorporation into the active channel. Excellent barrier properties of atomic-layer-deposited Al2O3 film could provide the feasibility for the direct deposition of organic planarization film without the need for an extra passivation layer. The proposed BiESL structure was also suggested to be compatible with the simple patterning process of Cu electrodes. (C) 2013 The Japan Society of Applied Physics