A Study of High Dielectric Constant Material TiO2 Deposited by Electron Beam Evaporation for DRAM Capacitors

• Main Authors: Liang, Ting-Hua, 梁庭華
• Other Authors: Su Shyang
• Format: Others
• Language: zh-TW
• Published: 1996
• Online Access: http://ndltd.ncl.edu.tw/handle/04098952902900584893

碩士 === 國立交通大學 === 電子研究所 === 84 === In this work, the effects of electrode materials (W, WN, Ta, TaN, Mo, and TiN)on the leakage current of TiO2 films were studied. The optimum electrode materials for high- and low- temperature processes (800 ℃ and 400 ℃) are shown. No obvious correlation between ψms and Vcrit (voltage at 10E-6 A/ cm2)is found in our experimental results. We also discussed post-TiO2-deposition annealing effect using TaN top electrode. The effects of annealing ambient, annealing temperature, and annealing time are included. In annealing ambient effect, temperature dependence of leakage current was investigated. On the other hand, the effects of TiO2 film thickness and doping concentration of boron-doped substrate were analyzed. We have then demonstrated that rapid thermal N2O (RTN2O) annealing is the most effective method in suppressing leakage current of TiO2 films, compared with furnace O2 (FO) and rapid thermal O2 (RTO) annealing. For future studies, optimal process conditions of RTN2O annealing are required to further improve performance of TiO2 capacitors.