Artificially nanostructured Cu:Al2O3 films produced by pulsed laser deposition

Abstract

The processes leading to the formation of Cu:Al2O3 composite films on Si (001) with a well defined nanostructure by alternate pulsed laser deposition (a-PLD) in vacuum are investigated. Alternately amorphous Al2O3 layers and Cu nanocrystals nucleated on the Al2O3 surface are formed, according to the PLD sequence. The Al2O3 deposited on the Cu nanocrystals fills in the space between them until they are completely buried, and subsequently, a continuous dense layer with a very flat surface (within 1 nm) is developed. The nucleation process of the nanocrystals and their resulting oblate ellipsoidal shape are discussed in terms of the role of the energetic species involved in the PLD process and the metal-oxide interface energy.