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 ZrO ₂ 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. © 2005 Elsevier B.V. All rights reserved.