Laminated Al2O3–HfO2 layers grown by atomic layer deposition for microelectronics applications

Abstract

Nanolaminated Al2O3–HfO2 and Al2O3/HfO2 bilayer thin films have been grown by plasma enhanced atomic layer deposition on silicon substrates. The nanolaminated system consists of alternating layers of Al2O3 and HfO2, while the bilayer system by contrast has been fabricated as a HfO2 about 15nm thick film deposited on a Al2O3 15nm thick film directly grown in contact with the silicon substrate. Both systems have been grown at a low temperature of 300°C and both systems possess 30nm total thickness. The dielectric properties and the structural evolution upon annealing treatment at 800°C of the nanolaminated system have been compared to those of the bilayer. The collected data pointed out to promising properties of the fabricated nanolaminated films.