Force Analysis Model for Elastomer CMP Pad by Diamond Tool
4 years ago
Authors:
Phạm Quốc Phong
Publication date:
01 / 06 / 2019
Name of Publishers:
International Journal of Mechanical & Mechatronics Engineering
Abstract:
Chemical mechanical polishing/planarization
(CMP) process is a primary wafer and thin film planarization
process for semiconductor fabrication. In CMP process, a
diamond dresser with well-distributed diamond grits is usually
applied to regenerate the surface topography of polishing pad
for maintaining the wafer material removal rate (MMR). This
paper aims to develop a model of reaction force on quasi-
orthogonal machining by a pyramid single-diamond tool on a
soft elastomer pad. Forces have been analyzed under two
dressing conditions which are face dressing direction (FDD) and
edge dressing direction (EDD). The reaction force model for the
pad has been investigated considering geometry of diamond grit
and contact areas between the diamond grit and the pad
surface. The reaction force profile obtained by experiment
agrees with a simulation of normal reaction forces. Results of
this study can be applied to predict diamond wear rate for
diamond dressing process. Furthermore, it can be extended to
design diamond dresser for optimum pad cutting rate (PCR)
during dressing process for semiconductor fabrication.