Facile synthesis of AlOx dielectrics via mist-CVD based on aqueous solutions

Abstract

Aluminum oxide (AlOx) thin films were synthesized by mist-chemical vapor deposition (mist-CVD) using aluminum acetylacetonate (Al(acac)(3)) dissolved in an aqueous solvent mixture of acetone and water. Nitrogen gas was used to purge the precursor solution and growth rates between 7.5-13.3 nm/min were achieved at substrate temperatures of 250-350 degrees C. The AlOx layers deposited at temperatures below 350 degrees C exhibit 3-5 at% residual carbon levels, however those grown at 350 degrees C exhibit only 1-2 at% carbon impurity. Reasonable dielectric properties were obtained in the latter, with a dielectric constant (kappa) of similar to 7.0, breakdown field of 9 MV/cm and relatively low leakage current density of similar to 8.3 x10(-10) A/cm(2).