3D-Printed CMP Pads with Tunable Zeta Potential
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Solution Overview
Problem
Current chemical-mechanical polishing (CMP) processes suffer from defects due to abrasive particles and metallic contaminants, which are difficult to remove, leading to suboptimal planarization of semiconductor substrates.
Innovation Solution
The development of tunable composite polishing articles, specifically 3D-printed CMP pads with adjustable hydrophilicity and zeta potential, utilizing cationic monomers and porosity-forming compositions to enhance the polishing process by repelling contaminants and improving substrate planarization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional polishing pads are used, then polishing process can be performed, but defects are generated due to abrasive particles and metallic contaminants
Solution Approach 1:
The patent changes the chemical parameters of the polishing pad by incorporating cationic monomers with positive charge groups. This parameter change modifies the electrostatic interaction between the pad and contaminants, causing metallic particles and abrasive contaminants to be repelled from the polishing interface, thereby reducing defects without compromising polishing quality
Solution Approach 2:
The patent creates a composite polishing pad material combining conventional polymeric matrix with cationic monomer components. This composite structure provides both the mechanical functionality of the base material and the contaminant-repelling properties of the cationic groups, achieving improved polishing quality while mitigating harmful contaminant effects
2Manufacturing precision
If abrasive polishing slurries are used, then planarization can be achieved, but abrasive particles damage the substrate surface
Solution Approach 1:
The patent converts the harmful effect of abrasive particles by using cationic monomers to create electrostatic repulsion. The same electrostatic forces that would normally attract charged abrasive particles to the substrate are now reversed, causing particles to be repelled from the polishing interface. This transforms the harmful abrasive action into a protective effect while maintaining planarization capability
3Productivity
If metallic contaminants are generated during CMP, then polishing process continues, but contaminants embed in substrate and are difficult to remove
Solution Approach 1:
The patent applies preliminary anti-action by incorporating cationic monomers into the polishing pad before the polishing process begins. These positive charge groups create an electrostatic barrier that repels metallic contaminants as they are generated during polishing, preventing their embedding in the substrate. This preliminary protective action occurs continuously throughout the polishing process, maintaining substrate cleanliness without reducing productivity
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 effectively reduces defects and improves the planarization efficiency by controlling the zeta potential and hydrophilicity of the polishing pad, effectively removing contaminants and enhancing the polishing process.
Implementation Method 1
tunable properties such as hydrophilicity and zeta potential... The addition or subtraction of protonated groups on a solid surface generates a charge on the surface... The electrostatics between the solid and liquid interface has a large influence on the charge of the interfacial double layer
Implementation Method 2
tunable properties such as hydrophilicity and zeta potential... Increasing the hydrophilicity and tuning the Zp of the pads
Implementation Method 3
dispensing one or more droplets of a porosity-forming composition onto the support, wherein at least one component of the porosity-forming composition is removable to form the pores in the porous polishing pad
Implementation Method 4
The curable resin precursor composition comprises a first resin precursor component that comprises a multifunctional acrylate oligomer, a second resin precursor component that comprises a multifunctional acrylate monomer... exposing the one or more droplets of the curable resin precursor composition to electromagnetic radiation to at least partially cure the curable resin precursor composition
Data Source
AI summary
In one implementation, a method of forming a porous polishing pad is provided. The method comprises depositing a plurality of composite layers with a 3D printer to reach a target thickness. Depositing the plurality of composite layers comprises dispensing one or more droplets of a curable resin precursor composition onto a support. Depositing the plurality of composite layers further comprises dispensing one or more droplets of a porosity-forming composition onto the support, wherein at least one component of the porosity-forming composition is removable to form the pores in the porous polishing pad.