Medium Frequency Physical Vapor Deposited Al2O3 and SiO2 as Etch-Stop-Layers for Amorphous Indium-Gallium-Zinc-Oxide Thin-Film-Transistors

article
In this work, we report on amorphous-Indium-Gallium-Zinc-Oxide (a-IGZO) thin-film transistor (TFT) with medium frequency physical vapor deposited (mf-PVD) etch-stop-layer (ESL). TFT with mf-PVD ESL show comparable characteristics such as fieldeffect mobility (μFE), sub-threshold slope (SS−1) and current ratio (ION/OFF) to the conventional plasma enhanced chemical vapor deposition (PECVD) ESL based TFT, however significant differences were observed in gate bias-stress stabilities. The TFTs with mf-PVD ESL showed lower threshold-voltage (VTH) shifts compared to TFTs with PECVD ESL when stressed under a gate field of +/−1 MV/cm for duration of 104 seconds in dark and light conditions. We associate the better bias-stress stability of the mf-PVD ESL based TFT to better passivating properties and the low hydrogen content of the mf-PVD layer compared to PECVD layer.
TNO Identifier
868223
Source
ECS Journal of Solid State Science and Technology, 4(2), pp. Q38-Q42.
Pages
Q38-Q42