MOS Characteristics of synthesized HfAlON-HfO2 stack using AlN-HfO2

Abstract

We demonstrate a top-surface aluminized and nitrided HfO2 gate dielectric using a synthesis of ultrathin aluminum nitride (AlN) and HfO2. The reaction of AlN with HfO2 through a subsequent high-temperature annealing incorporates Al and N into an HfO2 layer, which results in a synthesis of HfAlON near the top surface of HfO2, forming an HfAlON-HfO2 stack structure. This approach suppresses interfacial layer growth and improves thermal stability of the dielectric, resulting in significant improvement in leakage current. It also shows no adverse effects caused by N and Al incorporation at the bottom interface. © 2004 IEEE.