The Effect of Lanthanum (La) Incorporation in Ultra-Thin ZrO2 High-k Gate Dielectrics

• Main Author: 周益賢
• Other Authors: 劉傳璽
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/77966009299506483899

碩士 === 國立臺灣師範大學 === 機電科技研究所 === 98 === This study is mainly to investigate the La doping effect on the electrical properties of ultra-thin La-doped ZrO2 (denoted by ZrLaO) films for high-k gate dielectric applications of advanced logic technologies. In this work, ZrLaO films were co-deposited on p-type Si wafers by RF magnetron sputtering in the Ar ambient at room temperature, where ZrO2 and La targets utilized RF power and DC power, respectively, for sputtering. For comparison, ZrO2 films of similar physical thickness were also independently formed on Si wafers. A post-deposition annealing (PDA) was then performed in N2 ambient at 650℃ and 850℃. To form MOS structures, Al was sputtered as the top electrode, followed by annealing at 400℃ in N2. The film thickness was determined by ellipsometry and high-resolution transmission electron microscopy (HRTEM). The crystallization phase of ZrO2 and ZrLaO after PDA was investigated by X-ray diffraction (XRD). The electrical properties of ZrO2 with or without La incorporation were also analyzed and compared, including leakage current measured at 300-450 K, dielectric constant, flat-band voltage shift, current conduction behavior, and Schottky barrier height.