Research on a Novel Planarization Method as an Alternative or Complement to CMP

摘要

Research into an alternative or complementary method of substrate planarization is reported. This new technology is based on applying a sacrificial planarization coating to a substrate, pressing this coating layer against an optically flat surface, and using either an etch-back or CMP process to transfer the flat surface of the planarization material to the substrate layer or layers. In the past, etch-back processes have been used extensively for planarizing dielectric materials. However, poor local planarization caused by pattern density variations limits this technology. CMP also has difficulty planarizing over different pattern densities. By using the new press planarization step, the planarization of the sacrificial material is not affected by pattern density. When etch-back and CMP processes are coupled with this technology, improved results can be obtained. At this time most of the research is focused on maximizing within-die and within-wafer planarization of the sacrificial layer and the etch-back process. This paper describes the sacrificial planarization material, etch performance, pertinent process factors, benefits, and an outline of future work.