Porous Pad Chemical Planarization Without Abrasive Slurry
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Solution Overview
Problem
Conventional chemical mechanical planarization (CMP) processes are dirty, prone to defects, and unpredictable, causing yield loss and increased maintenance costs due to abrasive slurry, mechanical abrasion, and unpredictable processes.
Innovation Solution
A method of chemical planarization using an abrasive-free solution on a porous pad, where the pad selectively removes material from higher substrate topologies through controlled contact, utilizing hydrolyzing and complexing agents within the pad layers, and employing lower pressure and rotational speeds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional CMP process uses abrasive slurry and mechanical abrasion, then material removal efficiency is improved, but defect generation and contamination increase
Solution Approach 1:
The patent replaces the mechanical abrasion system (abrasive slurry and mechanical friction) with a chemical system. The porous pad contains hydrolyzing and complexing agents that chemically remove material from the substrate surface through contact, eliminating the need for abrasive particles and mechanical scratching while maintaining material removal capability.
Solution Approach 2:
The invention uses a porous pad structure where the pores contain and deliver chemical agents directly to the substrate surface. The porous structure allows controlled release of hydrolyzing and complexing agents during the planarization process, enabling chemical material removal without requiring abrasive slurry.
2Productivity
If conventional CMP process uses high pressure and rotational speed, then planarization speed is improved, but process unpredictability and maintenance costs increase
Solution Approach 1:
The patent changes the fundamental operating parameters from high mechanical stress (high pressure and rotational speed) to low mechanical stress with chemical activity. The porous pad is contacted at lower pressures, and the planarization speed is controlled by chemical reaction rates rather than mechanical friction, leading to more predictable and controllable process outcomes.
3Productivity
If conventional CMP process uses abrasive slurry, then material removal capability is improved, but cleanliness and yield are worsened
Solution Approach 1:
The patent eliminates the abrasive slurry system entirely by substituting it with a chemical planarization mechanism. The porous pad delivers hydrolyzing and complexing agents that dissolve and remove material chemically, preventing the generation of abrasive particles and slurry contamination that plague conventional CMP processes.
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
Reduces defects and contamination, enhances process predictability, and lowers maintenance costs by eliminating mechanical abrasion and abrasive slurry, improving yield and productivity.
Implementation Method 1
utilizing hydrolyzing and complexing agents within the pad layers
Implementation Method 2
utilizing hydrolyzing and complexing agents within the pad layers
Data Source
AI summary
Examples are disclosed that relate to planarizing substrates without use of an abrasive. One example provides a method of chemically planarizing a substrate, the method comprising introducing an abrasive-free planarization solution onto a porous pad, contacting the substrate with the porous pad while moving the porous pad and substrate relative to one another such that higher portions of the substrate contact the porous pad and lower portions of the substrate do not contact the porous pad, and removing material from the higher portions of the substrate via contact with the porous pad to reduce a height of the higher portions of the substrate relative to the lower portions of the substrate. In some examples, linear motion may be used for chemically planarizing.