Campus Units

Aerospace Engineering, Mechanical Engineering

Document Type

Article

Publication Version

Published Version

Publication Date

8-2005

Journal or Book Title

Journal of Manufacturing Science and Engineering

Volume

127

Issue

3

First Page

545

Last Page

554

DOI

10.1115/1.1949616

Abstract

A scratch intersection based material removal mechanism for CMP processes is proposed in this paper. The experimentally observed deformation pattern by SEM and the trends of the measured force profiles (Che et al., 2003) reveal that, for an isolated shallow scratch, the material is mainly plowed side-way along the track of the abrasive particle with no net material removal. However, it is observed that material is detached close to the intersection zone of two scratches. Motivated by this observation, it is speculated that the deformation mechanism changes from ploughing mode to shear-segmentation mode as the abrasive particle approaches the intersection of two scratches under small indentation depth for ductile metals. The proposed mechanistic material removal rate (MRR) model yields Preston constant similar to those observed experimentally for CMP processes. The proposed model also reveals that the nature of the slurry-pad interaction mechanism, and its associated force partitioning mechanism, is important for determining the variation of MRR with particle size and concentration. It is observed that under relatively soft pads, small particles and low particle concentration, the pad undergoes local deformation, yielding an increased MRR with increasing particle size and concentration. At the other extreme, the intact walls of the surface cells and the connecting cell walls between the surface pores deform globally, resembling a beam or a plate, and a decreasing trend in MRR is observed with increasing particle size and concentration. The predicted MRR trends are compared to existing experimental observations.

Comments

This article is from Journal of Manufacturing Science and Engineering 127 (2005): 545, doi: 10.1115/1.1949616. Posted with permission.

Copyright Owner

ASME

Language

en

File Format

application/pdf

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