High quality SiO2 gate insulator suitable for poly-Si TFTs on plastic substrates employing inductively coupled plasma-chemical vapor deposition with N2O plasma treatment and excimer laser annealing

Abstract

Electrical characteristics, such as capacitance–voltage characteristics (C–V) and break-down field, of SiO2 films deposited on plastic substrates by inductively coupled plasma chemical vapor deposition at 150°C were improved by excimer laser annealing and N2O plasma pre-treatment. Excimer laser annealing at an energy density of 250mJ/cm2 produced a flat-band voltage of the SiO2 film shifted close to 0V while the effective oxide charge density considerably reduced. The breakdown field was improved from 7MV/cm to 9.5MV/cm after N2O plasma treatment. By employing excimer laser annealing and N2O plasma pre-treatment, the flat-band voltage was improved from −9V to −1.8V and the effective charge density was reduced to the level found for TEOS SiO2 deposited at 400°C.