Growth and electrical properties of AlOx grown by mist chemical vapor deposition

Abstract

Aluminum oxide (AlOx) thin films were grown using aluminum acetylacetonate (Al(acac)3) as a source solute by mist chemical vapor deposition (mist CVD). The AlOx thin films grown at temperatures above 400°C exhibited a breakdown field (EBD) over 6 MVcm and a dielectric constant (κ) over 6. It is suggested that residual OH bonding in the AlOx thin films grown at temperatures below 375°C caused degradation of the breakdown field (EBD). With FC type mist CVD, the reaction proceeded efficiently (Ea 22-24 kJmol) because the solvent, especially H2O, worked as a stronger oxygen source. The AlO x film could be grown at 450°C with a high deposition rate (23 nmmin) and smooth surface (RMS 1.5 nm). Moreover, the AlOx thin films grown by mist CVD had excellent practicality as insulators because the gate leakage current (IG) of the oxide thin film transistor (TFT) with an IGZOAlOx stack was suppressed below 1 pA at a gate voltage (V G) of 20 V. © 2013 Copyright 2013 Author(s). This article is distributed under a Creative Commons Attribution 3.0 Unported License.