Polishing Liquid for Fixed Abrasive Pad Conditioning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing CMP methods are inadequate for conditioning fixed abrasive polishing pads, as conventional conditioners can tear the pad material, leading to uneven polishing and defects in workpieces, while brushing has limited effectiveness and may cause scratching.
Innovation Solution
A polishing liquid with chemically inert, polymeric particles is used to remove deposits from fixed abrasive polishing pads, which are designed to be mechanically compatible with the pad material, allowing for simultaneous polishing and conditioning without damaging the pad or workpieces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional conditioners are used to remove deposits from the polishing pad, then the polishing surface can be restored, but the pad material is torn and uneven polishing occurs
Solution Approach 1:
The patent replaces the mechanical conditioning system (abrasive end effector) with a chemical-mechanical polishing liquid system. The polishing liquid contains particles that mechanically remove deposits while chemicals prevent pad material damage, substituting the harsh mechanical conditioning process with a gentler combined chemical-mechanical approach that restores the polishing surface without tearing the pad.
Solution Approach 2:
The polishing liquid comprises a composite formulation combining chemically inert particles (for mechanical deposit removal) with chemicals (for etching/oxidizing workpiece surfaces and protecting pad material). This composite material approach allows simultaneous deposit removal and pad protection, resolving the contradiction between surface restoration and polishing uniformity.
2Object-generated harmful factors
If brushing is used to clean the polishing pad, then deposits can be removed, but scratching of the pad or workpieces may occur
Solution Approach 1:
The patent replaces the brushing mechanical cleaning system with a polishing liquid system. The liquid delivers fine particles that gently remove deposits through controlled mechanical action combined with chemical effects, substituting the aggressive brush contact that causes scratching with a gentler particle-based cleaning mechanism.
Solution Approach 2:
The patent changes the parameters of the cleaning mechanism by using suspended particles with controlled size, hardness, and concentration in the polishing liquid. These parameters are optimized to remove deposits effectively while being soft enough to prevent scratching, unlike rigid brush bristles.
3Reliability
If separate conditioning operations are performed, then the polishing pad can be maintained, but process time and complexity increase
Solution Approach 1:
The patent merges the conditioning function with the polishing operation by incorporating deposit-removing particles and protective chemicals directly into the polishing liquid. This combines what were previously separate operations (polishing and conditioning) into a single integrated process, eliminating dedicated conditioning time while maintaining pad performance.
Solution Approach 2:
The polishing liquid serves multiple functions simultaneously: it removes deposits from the polishing pad, protects the pad material from damage, and performs the primary polishing function. This multi-functionality eliminates the need for separate conditioning operations, reducing process time while maintaining pad reliability.
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 solution enhances the uniformity and efficiency of the polishing process, reduces defects, and eliminates the need for separate conditioning operations, resulting in a cleaner and more stable polishing surface.
Implementation Method 1
A polishing liquid with chemically inert, polymeric particles is used to remove deposits from fixed abrasive polishing pads
Implementation Method 2
particles that are at least approximately chemically inert with respect to the abrasive elements... mechanically compatible with the pad material
Data Source
AI summary
Polishing liquids for activating and/or conditioning fixed abrasive polishing pads, and associated systems and methods are disclosed. A method in accordance with one embodiment of the invention includes disposing a polishing liquid on a polishing surface of a microfeature workpiece polishing pad. The polishing pad can include a matrix material and a plurality of abrasive elements fixedly distributed in the matrix material. The polishing liquid can include a plurality of particles that are at least approximately chemically inert with respect to the abrasive elements. In a particular embodiment, the particles can have a polymeric, non-ceramic composition. The method can further include moving at least one of the polishing pad and the plurality of particles relative to the other to remove deposits from the polishing pad. This operation can be performed serially or simultaneously with using the polishing pad to remove material from a microfeature workpiece.