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

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.