An Analytical Model for Step Height Reduction in CMP with Different Pattern Densities

The material removal rate during chemical mechanical polishing (CMP) depends sensitively on pattern geometry and density. Different material removal rates in CMP result in excessive erosion of the dielectric layer or dishing of metal lines. An analytical model for step height reduction is proposed using a linear system method. The magnitude spectra and the phase spectra of a specified CMP process are given. The evolutions of polishing height in the up area and polishing height in the down area for different pattern density, pad stiffness, and down pressure and slurry selectivity are presented and compared with the experimental data. The evolution of the topography on the wafer surface is simulated. The influences of the polish parameters on the step height reduction on CMP at different cases are discussed.

[1]  David Dornfeld,et al.  Effects of abrasive size distribution in chemical mechanical planarization: modeling and verification , 2003 .

[2]  T. Cale,et al.  Multiscale material removal modeling of chemical mechanical polishing , 2003 .

[3]  Abhijit Chandra,et al.  An analytical dishing and step height reduction model for chemical mechanical planarization (CMP) , 2003 .

[4]  Lixiao Wu.  Analytical Model for Chemical Mechanical Polishing of Features with Different Pattern Density , 2006 .

[5]  Joost J. Vlassak,et al.  A model for chemical–mechanical polishing of a material surface based on contact mechanics , 2004 .

[6]  David Dornfeld,et al.  Material removal regions in chemical mechanical planarization for submicron integrated circuit fabrication: coupling effects of slurry chemicals, abrasive size distribution,and wafer-pad contact area , 2003 .

[7]  Nannaji Saka,et al.  Evolution of Copper-Oxide Damascene Structures in Chemical Mechanical Polishing I. Contact Mechanics Modeling , 2002 .

[8]  Frank G. Shi,et al.  Modeling of chemical-mechanical polishing with soft pads , 1998 .

[9]  Yeau-Ren Jeng,et al.  A Material Removal Rate Model Considering Interfacial Micro-Contact Wear Behavior for Chemical Mechanical Polishing , 2005 .

[10]  David Dornfeld,et al.  Material removal mechanism in chemical mechanical polishing: theory and modeling , 2001 .

[11]  S. Runnels.  Feature‐Scale Fluid‐Based Erosion Modeling for Chemical‐Mechanical Polishing , 1994 .

[12]  Leon M Keer,et al.  Wear‐Contact Problems and Modeling of Chemical Mechanical Polishing , 1998 .

[13]  D. Boning,et al.  Characterization and modeling of oxide chemical-mechanical polishing using planarization length and pattern density concepts , 2002 .