CMP Pad with Non-Expandable Particles for Planarization
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Solution Overview
Problem
Conventional chemical mechanical polishing pads, both porous and non-porous, face challenges in achieving effective planarization due to issues like deformation and dishing, with porous pads being less effective and non-porous pads being difficult to machine with desired macrotexture and microtexture.
Innovation Solution
A chemical mechanical polishing pad with a matrix polymer and 1 to 20 wt % non-reactive, non-expandable polymeric particles, along with less than 2 wt % expandable polymeric microspheres, providing a polishing layer with crescent-shaped openings that enhance planarization and machinability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If porous pads are used, then microtexture is provided through pore expansion, but planarization effectiveness decreases due to excessive conformance to substrate variations
Solution Approach 1:
The patent changes the physical state of polymeric particles from expandable (porous) to non-expandable (solid), fundamentally altering how microtexture is formed. Instead of relying on pore expansion during conditioning, the invention uses pre-formed solid particles that create microtexture through their physical presence and interaction with the substrate during polishing, thereby maintaining rigidity while achieving effective planarization
Solution Approach 2:
The patent creates a composite polishing layer combining a matrix polymer with dispersed non-reactive non-expandable polymeric particles. This composite structure provides both the rigidity needed for effective planarization and the microtexture necessary for polishing performance, resolving the contradiction between manufacturability and planarization effectiveness
2Manufacturing precision
If non-porous pads are used, then rigidity and planarization effectiveness improve, but machinability deteriorates due to difficulty in creating desired macrotexture
Solution Approach 1:
The patent changes the physical state of polymeric particles from expandable to non-expandable, which fundamentally alters the material's response to machining. The non-expandable solid particles maintain their shape and size during manufacturing, enabling precise control over macrotexture formation through machining while preserving the rigidity needed for effective planarization
Solution Approach 2:
The patent introduces local heterogeneity by dispersing non-reactive non-expandable polymeric particles throughout the matrix polymer. These particles create localized regions with different physical properties, enabling precise control over macrotexture formation in specific areas while maintaining overall rigidity and planarization effectiveness
3Ease of manufacture
If expandable polymeric microspheres are used, then porosity and microtexture are achieved, but dishing and deformation increase during polishing
Solution Approach 1:
The patent fundamentally changes the physical state of polymeric particles from expandable to non-expandable. This parameter change eliminates the volume expansion that causes dishing and deformation during polishing, while still achieving microtexture through the physical presence and interaction of solid particles with the substrate
Solution Approach 2:
The patent uses non-reactive non-expandable polymeric particles that maintain their structural integrity throughout the polishing process. Unlike expandable microspheres that change volume and cause deformation, these solid particles remain stable, providing consistent microtexture without inducing dishing or deformation
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The polishing pad achieves improved planarization with reduced dishing and enhanced machinability, maintaining rigidity while allowing for precise macrotexture creation, effectively polishing substrates without substantial deformation or defects.
Implementation Method 1
the polishing layer comprises a matrix polymer and 1 to 20 wt % based on total weight of the polishing layer of non-reactive, non-expandable polymeric particles dispersed in the matrix polymer and less than 2 wt % expandable polymeric microspheres
Implementation Method 2
an SEM of a cut surface of the polishing layer shows a crescent shaped opening adjacent to at least a portion of the polymer particles and separating a surface of that portion of the polymer particles from the matrix polymer
Implementation Method 3
The carrier assembly provides a controllable pressure between the wafer and polishing pad
Implementation Method 4
a polishing medium (e.g., polishing solution or slurry) is dispensed onto the polishing pad and is drawn into the gap between the wafer and polishing layer
Data Source
AI summary
A chemical mechanical polishing pad includes a polishing layer. The polishing layer comprises a matrix polymer and 1 to 20 wt % based on total weight of the polishing layer of non-reactive, non-expandable polymeric particles dispersed in the matrix polymer and less than 2 wt % expandable polymeric microspheres. An SEM of a cut surface of the polishing layer shows a crescent shaped opening adjacent to at least a portion of the polymer particles and separating a surface of that portion of the polymer particles from the matrix polymer.