Fixed Charge Induced by Ion Implantation Used to Control the Threshold Voltage for Oxide TFTs

We propose Ar-ion $(\text{Ar}^{+})$ incorporation into an $\text{SiO}_{2}$ layer through a thin Al layer by ion implantation to control the threshold voltage $(V_{\text{th}})$ of metal-oxide-semiconductor (MOS). We demonstrate that $1\mathrm{x}10^{15}-\text{cm}^{-2}-\text{Ar}^{+}$ implantation at 10 keV effectively decreased positive fixed oxide charges by 3 $3\mathrm{x}10^{11}\text{cm}^{-2}$ for a MOS sample of 10-nm Al/100-run $\text{SiO}_{2}/\text{Si}$ substrate. This method will be useful to control $V_{\text{th}}$ for IGZO TFTs.