Optimization of polishing kinematics and consumables during chemical mechanical planarization processes.

摘要

This dissertation presents a series of studies relating to optimization of kinematics and consumables during chemical mechanical planarization processes. These are also evaluated with the purposes of minimizing environmental and cost of ownership impacts.;In order to study diamond micro-wear and substrate wear during planarization processes, a series of static etch tests and wear tests were performed using different types of diamond discs subjected to various treatments. Scanning Electron Microscopy (SEM) and Inductively Coupled Plasma Membrane Spectroscopy (ICPMS) were used to estimate the extent of diamond micro-wear and substrate wear.;Next, the impact of various factors (type of slurry abrasive, pH, abrasive content and abrasive concentration) on pad wear rate during the planarization process was studied. Another study in this dissertation focuses on the development of a novel technique of using coefficient of friction (COF) data to distinguish between good and bad diamond discs. This study made use of the innovative tool diamond disc dragging device (DDD-100) designed and developed for the purpose of this study.;It is known that the performance of chemical mechanical planarization depends significantly on the polishing pad grooving type and the kinematics involved in the process. Variations in pad grooving type as well as pressure and sliding velocity can affect polishing performance. One study in this dissertation investigates the effect of pressure and sliding velocity on the polishing performance. The study is conducted with multiple pressure and sliding velocity variations to understand the characteristics of each condition. A subsequent study focuses on the impact of pad grooving type on polishing performance.;The greatest contribution of this dissertation involves development of a novel slurry injector to optimize the utilization of slurry during planarization processes. Slurry is a critical component in chemical mechanical planarization processes and accounts for approximately 50 percent of the cost of ownership (CoO). The novel injector, apart from reducing the consumption of slurry, also contributed in addressing problems associated with foaming, reduced the number of defects and achieved better within wafer non-uniformity (WIWNU).