Facile fabrication of p-type Al2O3/carbon nanocomposite films using molecular layer deposition

Abstract

Molecular layer deposition (MLD) is an organic thin film deposition method with high uniformity and precise controllability over thickness. "Alucone (aluminum alkoxide)" thin film was fabricated by MLD using hydroquinone (HQ) and trimethylaluminum (TMA) precursors at 200 degrees C. Upon exposure to 50% humidity condition at 25 degrees C, HQ-TMA alucone films shows decrease of thickness and increase of roughness, but with a considerable slower rate than its diethyleneglycol-TMA analogue. The alucone MLD thin films were annealed under vacuum at temperatures between 300 and 800 degrees C. Upon thermal annealing, the thickness of annealed alucone film contracts, and graphitic carbon regions appear according to Raman, Auger, and XPS analyses. The post-annealed Al2O3/carbon composite shows enhanced electrical conduction compared to as-deposited alucone, becoming a p-type semiconductor. When the alucone film is annealed at 750 degrees C, its carrier concentration exhibits the highest value of 2.7 x 10(19) cm(-3), with the lowest electrical resistivity of 8.7 x 10(-2) Omega cm. Currently developed p-type A1(2)O(3)/C composite films can be useful for various electronic applications.