Elastic Membrane with Bulging Partition Wall for CMP Pressure Uniformity
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Solution Overview
Problem
Conventional chemical mechanical polishing (CMP) systems face challenges in uniformly transmitting pressure to wafers due to the rigidity of elastic membranes with partition walls, leading to variations in film thickness and shape, which are not adequately controlled in the circumferential direction.
Innovation Solution
The elastic membrane is enhanced with a bulging partition wall structure that improves elasticity, allowing for better stretchability and uniform pressure distribution by forming pressurizing chambers and using fluid supply and vacuum mechanisms to apply and release pressure effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If partition walls are added to divide pressure chambers in the circumferential direction, then control of pressing force in circumferential direction is enabled, but the elastic membrane becomes difficult to stretch and pressure transmission uniformity deteriorates
Solution Approach 1:
The pressure chamber is divided into multiple regions by partition walls extending in the radial direction, enabling independent pressure control in different circumferential zones. This segmentation allows precise control of pressing force distribution while maintaining overall pressure transmission uniformity through optimized partition wall design
Solution Approach 2:
The partition walls are designed with varying thickness along their length, with thinner sections near the pressing surface and thicker sections near the backing plate. This local quality variation enables the membrane to stretch effectively while maintaining structural integrity and pressure transmission uniformity across different regions
2Strength
If elastic membrane is made rigid to maintain structural integrity, then durability is improved, but elasticity and stretchability deteriorate
Solution Approach 1:
The elastic membrane is designed with varying thickness parameters, being thinner in regions requiring high elasticity and stretchability, and thicker in regions requiring structural support. This parameter variation allows the membrane to exhibit both durability and elasticity simultaneously
Solution Approach 2:
The elastic membrane is constructed using composite material structure combining different material properties or layered configurations, enabling simultaneous achievement of structural integrity and elastic deformation capability under polishing conditions
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
This solution enables improved uniformity in film thickness and shape across the wafer surface, addressing the limitations of conventional CMP systems by enhancing the elasticity of the polishing head and membrane, thus ensuring more precise and consistent polishing results.
Implementation Method 1
supplying a fluid to a pressurizing chamber formed by a partition wall having a bulge structure to apply a pressing force to the pressing portion
Implementation Method 2
When applying a pressure to the pressure chamber formed of an elastic membrane made of an elastic material commonly used in a CMP apparatus, the elastic membrane expands and comes into close contact with the wafer
Implementation Method 3
supplying a fluid to a pressure chamber... while holding the substrate, to press the substrate against a polishing pad
Data Source
AI summary
An elastic membrane that can improve elasticity is disclosed. The elastic membrane has a pressing portion and a partition wall having a bulging structure.