Effects of Ti Addition on Via Reliability in Deep Submicron Copper Interconnects Process
We investigated the effects of a Ti addition on the reliability and the electrical performance of Cu interconnects, comparing three different ways of Ti addition such as a) Ti layer insertion under Ta-TaN stacked barrier metal, b) Ti layer insertion between a Ta-TaN barrier and Cu, and c) the Ti doping from the surface of the electrochemical-plated (ECP) Cu film.The structure-A drastically suppresses the ressinduced voiding (SIV) under the via connected to a wide lower line due to adhesion improvement by Ti at the via-bottom, while the electromigration (EM) is not improved. In the structure-B, by contrast, the EM is improved but the SIV resistance is degraded. The Ti doping from the bottom surface of Cu film restricts the grain growth and increases the tensile stress, enhancing the SIV. The structure-C improves not only the SIV but also the EM resistance. The author found that some oxygen-related atoms gettering effect of Ti during the ECP-Cu annealing is a reason for the reliability improvements of the SIV and the EM. The improvement of adhesiveness at the interface between the via and the lower Cu line, and the oxygen gettering from Cu by Ti play an important role in suppressing the SIV and the EM.
Po-Ying Chen Shih-Chun Hung Wen-Kuan Yeh Ming Hsiung Tsai I-Fen Chen Wei-Chou Chen Kang-Ping Li Pei-Chen Yeh Hsin-Ying Huang
Department of Information Engineering, I-Shou University, No. 1, Sec. 1, Syuecheng Road, Dashu Towns Department of Electronic Engineering, National University of Kaohsiung, No. 700, Kaohsiung Universit
国际会议
上海
英文
1657-1659
2010-11-01（万方平台首次上网日期，不代表论文的发表时间）