Establishing the discipline of physics-based CMP modeling

摘要

For the past decade, a physically based com- prehensive process model for chemical mechanical polishing has eluded the semiconductor industry. However, a long-term collaborative effort has now resulted in a workable version of that approach. The highly fundamental model is based on advanced finite element analysis and is beginning to show promise in CMP process development, When chemical mechanical polishing (CMP) modeling first emerged in the early 1990s, the computational cost of "solving the CMP problem" with brute force simulations was considered beyond reach. Thus, the term "CMP process model" became associated with the many phenomenological models created by investigators in the field. These models are actually mathematical encapsulations of investigators' understanding of the CMP process. As such, the models reproduce existing knowledge but cannot be used to explore new physical situations. Instead of replacing expensive experimental work, these models require more tests for validation, and then are limited to exploration in process segments close to where they have been validated. For this reason, the popularity and range of application of phenomenological models have been limited. Although to some extent, belief that the process can be modeled using physics has suffered, many of the key aspects of CMP are actually well understood in classical physics.