研磨墊調節之磨削機構及其對化學機械研磨(CMP)製程之影響

Abstract

在半導體的製程中,隨著線寬不斷的微縮與線路層數不斷增加‚晶圓表面凹凸不平也愈來愈嚴重,對黃光製程(微影製程)來說‚如何將光罩上的圖案轉移至晶圓上逐漸變成一項極為困難的挑戰‚而晶圓表面凹凸不平對PVD製程也容易造成階梯覆蓋能力(step coverage)變差造成電子遷移或高電阻的問題‚因而有了化學機械拋光(CMP)製程需求的產生,CMP製程除了可以將晶圓表面凹凸不平加以磨平以外,在更先進的銅製程更是需要CMP將多餘的銅移除.然而要維持CMP製程的穩定性適當的研磨墊及研磨墊調節器是扮演相當重要的腳色.本論文主要探討以新式研磨墊調節器(Pad conditioner)在化學機械拋光製程中來獲得更好更穩定的製程。

In advanced semiconductor processes, with continuously decrement in line dimension and increment in layers adopted for multi-layer interconnect structure, the challenge with surface flatness and topography becomes more and more serious. For photolithography technology, how to accurately transfer pattern definition from mask to wafer surface becomes a very difficult task. Moreover, the un-even topography on wafer surface also induces variations in step height coverage and results in concerns such as electron migration and high current resistance. Chemical Mechanical Planarization (CMP) has thus become the novel process to tackle these topography related issues. CMP not only enables planrized surface to remove uneven material but also removes excess Cu to define Cu line in advanced Cu technology. Therefore, it is critical to maintain process stability and robustness through optimization of pad and pad conditioner selection. This paper will explore roles in advanced pad conditioning configuration in enabling more stable and robust CMP processes.