Yield Improvement in Chemical Mechanical Planarization Via Material Removal Variation on a Surface

Download or read book Yield Improvement in Chemical Mechanical Planarization Via Material Removal Variation on a Surface written by Muthukkumar Kadavasal Sivaraman and published by . This book was released on 2005 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chemical Mechanical Planarization is one of the most required semiconductor processing modules used in fabrication facilities world wide. Among various surface material removal processes, CMP process is primed for its ability to obtain both local and global planarity on a given surface. The model developed by Fu and Chandra et al, calculates the dishing height based on MRR equations. The model provides a way for step by step material removal based on proportionality parameters like interface pressure, table speed and pattern density. The thesis provides a complete chart for developing a control mechanism for CMP process. The thesis bifurcate the approach into Die scale and Wafer Scale. In die scale, a comprehensive control algorithm is developed based on the MRR equations with pressure and velocity as the control parameter. The model establishes a control over the step height uniformity and upper surface uniformity in both uniform pattern density and varying pattern density surfaces. At wafer scale, an analytical model that relates wafer-pad interface pressure and carrier loading is explained and based on that a FEM analysis is carried out to study the impact of non uniform loading on wafer-pad interface. Both the die scale and wafer models, paved way for developing an integrated control flow chart that can have an impact on the wafer surface at both die scale and wafer scales at the same time. Although, a chart or flow map with necessary models and simulations are in place, to put the entire control mechanism work in a realistic environment there are many other requirements. Like a full fledged pixel or zonal controller should be developed and large scale experimental analysis should be performed based on real time data from manufacturing units.