减少缺陷及提高铜层化学机械抛光平面度的探讨

半导体器件上铜层化学机械抛光(CMP)的第一道工序一般需要使用一块硬抛光垫,在磨去阻挡层的工序中要用到软垫。在磨去阻挡层和电介质材料时,要把各家供应商的各种抛光液与这些抛光垫配合在一起使用。用于把铜大量地磨掉的硬垫,抛光后的平面度很好,而在磨掉阻挡层工序中使用的软垫,它所产生的缺陷很少,这是由于它本身的结构而且由于它很软的缘故。随着半导体器件变得越来越小、线条宽度缩小,半导体技术更不允许金属出现损失,也更不允许化学机械抛光出现缺陷。这些参数最终会影响器件的性能和成品率。因此市场需要一种化学机械抛光垫,它能够提高铜阻挡层的平面度,具备软垫进行抛光时缺陷少的优点。介绍一种新的化学机械抛光垫技术,它使用了专门设计的聚合物材料,从而满足产业界的要求。

The Quest for Reduced Defectivity While Maintaining Planarization in Copper CMP

Typical chemical mechanical polishing (CMP) of copper layers on semiconductor devices involves using a hard pad in the first step and a soft pad for the barrier layer removal step. Various slurries from a host of suppliers are used in conjunction with these pads to remove barrier and dielectric material. The hard pad used for the bulk removal of copper provides very good planarization, while the soft pad used in the barrier process yields very low defectivity due to its inherent structure and softness. As devices get smaller and line widths shrink, the technology becomes less tolerant of metal loss and CMP- related defects. These parameters ultimately impact device performance and yield. This has resulted in a market need for a CMP pad that improves planarization in the copper barrier step, while maintaining theexcellent defect levels achieved by soft pads. A new CMP pad technology is presented that incorporates specially engineered polymers designed to meet industry requirements.