The Influence of Feature-Scale Surface Geometry on CMP Processes

Abstract

The influence of feature-scale surface pattern dimensions on chemical mechanical polishing (CMP) processes has been studied through numerical simulations using a discretized geometry approach. The development of planarity for a symmetrical 3 ϫ 3 array of square roughness elements with various lateral dimensions and spacing was simulated. Geometrical shielding of roughness elements by neighboring elements was found to cause asymmetrical surface polishing during the CMP processes. Given a specified trench spacing, a stronger doming effect was predicted for smaller sized protrusions. For a fixed feature size, the most significant doming effect was found to occur when the trench width is comparable to the gap size between the pad and the protrusion. These effects can be associated with variations in the flow pattern of the polishing slurry in the vicinity of the roughness elements.

Optimization of tribological properties of silicon dioxide during the chemical mechanical planarization process

“…[1][2][3][4][5] Current semiconductor fabrication technology for logic and memory devices requires CMP to achieve the required multilevel interconnection densities. [1][2][3][4][5] Current semiconductor fabrication technology for logic and memory devices requires CMP to achieve the required multilevel interconnection densities.…”

Analysis of Feature-Scale Wear in Chemical Mechanical Polishing: Modeling and Experiments

“…Fluid mechanics: The effect of flowfield and hydrodynamic pressure of the slurry was not taken into account in this model. Past models have suggested that the slurry shear rate directly affects the wear of the wafer sample [1,26,27], while other studies have shown that the sample contact stress is affected by the slurry hydrodynamic pressure [35,36]. Neither of such assumptions are taken into account in the current model.…”

“…On the feature scale, studies by Chekina et al [21], Chang et al [22], Saxena et al [23], Nguyen et al [24], and Sawyer [25] have modeled dishing and erosion in CMP. Additionally, Yao et al [26,27] used shear-based wear modeling to predict the time evolution of surface features on a wafer sample.…”

Application of soft landing to the process control of chemical mechanical polishing

“…Chemical mechanical polishing (CMP) has the capability of achieving such stringent requirements over a step height of several microns. Since the introduction of the new technology in the 80s, the CMP provides advantages of defect reduction, wide windows for etching and lithography and yield improvement [5,6,13]. Combining the chemical reactions and mechanical force abrasion, the wafer surface can be polished to achieve global planarity.…”