cu低k互连系统可靠性研究微电子学与固体电子学专业论文.docxVIP

AbstractAbstract Abstract Abstract The main purpose of this article is to study the reliability of copper／low—k interconnects，especially on Electromigration and Stress—migration failure．The test method and failure mechanism of Electromigration were studied，and effective methods to improve the electromigration reliability were discussed．Finite Element Analysis was used to study residual stress in Cu interconnects，different structures including various via diameter,line width，residual length，and dielectric material were investigated to analyze structural effects on residual stress．Stress．induced voiding test of Cu interconnects had been done to observe the voiding location．Stress—induced voiding failure in Cu interconnects with different via diameter Was studied．The voiding mechlaaism and the effect of via size on stress migration had been studied． The results indicated that the Cu／dielectric interface Was the fastest diffusion path． improving the interface characteristic Can effectively depress Electromigration failure． Residual stress reached the maximum value inside the vi巩and stress gradient achieved the peak value in 10Wer metal line under the COmer of the via．Residual stress decreased as the via diameter or the dielectric constant of lLD decreasing，and increased as the line width or the residual length decreasing．Stress gradient decreased as the via diameter, the dielectric constant of ILD or the residual length decreasing，and increased as the line width increasing．The vacancies diffused in the direction of the stress gradient and nucleate at the peak value of the stress gradient．The voiding rate Was eO—determined by the stress and the stress gradient． Keyword：Cu interconnects failure Electromigration Stress—migration 西安电子科技大学 西安电子科技大学 学位论文独创性(或创新性)声明 秉承学校严谨的学分和优良的科学道德，本人声明所呈交的论文是我个人在 导师指导下进行的研究工作及取得的研究成果。尽我所知，除了文中特别加以标 注和致谢中所罗列的内容以外，论文中不包含其他人已经发表或撰写过的研究成 果；也不包含为获得西安电子科技大学或其它教育机构的学位或证书而使用过的 材料。与我一同工作的同志对本研究所做的任何贡献均已在论文中做了明确的说 明并表示了谢意。 申请学位论文与资料若有不实之处，本人承担一切的法