微细凹槽电沉积铜工艺及影响因素研究

Study on Electrodeposition Process of Copper in Micro-grooves and Its Influencing Factors

微细凹槽内无空洞和缝隙缺陷铜填充是集成电路芯片铜布线制造工艺技术需解决的关键问题。采用酸性镀铜工艺,在镀铜硅片上开展了微细凹槽内电沉积铜填充研究;采用正交试验法和单因素实验,分析了电沉积过程中重要因素的影响排序和作用机理。研究结果表明,各影响因素数值的增加均能提高凹槽的填充率,电流密度和加速剂浓度的增加可以提高凹槽的填充速率,而电镀时间和整平剂浓度的增加以及过大的加速剂浓度则会降低填充速率。

The best way to optimize copper wiring manufacturing technology of integrated circuit chips would be to remedy copper filling without cavity and gap defects in micro-grooves.The electrodeposition of copper in fine grooves on copper-plated silicon wafers is carried out with acid copper plating process.According to orthogonal experiment and single factor experiment,the influence order and mechanism of important factors in electrodeposition process were analyzed. The results show that the filling rate of the groove can be improved by increasing the value of each influencing factor. The filling speed of the groove can be improved by increasing the current density and the concentration of accelerator,while the filling rate can be reduced by increasing the plating time,the concentration of leveling agent and the excessive concentration of accelerator.