Plasma nitridation and microstructure of high-k ZrO2 thin films fabricated by cathodic arc deposition

ZrO2 thin films as high-k gate dielectric materials are deposited by hybrid cathodic arc deposition involving oxygen and nitrogen gases and their properties are investigated. The incorporation of N into the ZrO2 structure increases the crystallization temperature, and the microstructure of the nitrided ZrO2 thin films is improved based on X-ray diffraction and atomic force microscopy characterization. The enhancement is believed to be due to the formation of Zr-N bonds that increase the degree of particle disorder in the thin films. Our study suggests that a hybrid cathodic arc deposition process conducted in the presence of nitrogen is an effective method to improve the properties of ZrO2 thin films. The new process can be applied to other gate dielectrics and may accelerate the development of alternative high k dielectric thin films in advanced microelectronic devices and structures.