Compliant Polishing Pad with Inflatable Base for Local Pressure Control
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Solution Overview
Problem
Conventional substrate polishing methods face challenges in achieving precise local material removal due to the redistribution of pressure, leading to non-planarity and uneven material removal, which can damage devices and reduce yield.
Innovation Solution
A polishing system with a flexible base and inflatable polishing pad that adjusts its contact area based on pressure, allowing for fine resolution and controlled pressure application to address local polishing needs, minimizing dishing and erosion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If carrier head applies differential pressure to peripheral edges for greater material removal, then material removal at edges is improved, but substrate stiffness redistributes pressure causing smoothing effect that makes local pressure application difficult
Solution Approach 1:
The polishing pad is segmented into multiple independently controllable regions, each capable of applying different pressure levels. This allows localized pressure application to specific areas of the substrate without the pressure being redistributed across the entire substrate by carrier head stiffness.
Solution Approach 2:
The polishing pad incorporates a flexible base with inflatable structures that enable dynamic adjustment of contact pressure and contact area. This dynamic control allows the system to adapt pressure distribution in real-time, overcoming the static pressure redistribution problem caused by substrate stiffness.
2Manufacturing precision
If conventional polishing systems are used on non-planar substrates, then polishing process is simple, but certain regions experience over-removal or under-removal of material damaging devices
Solution Approach 1:
The polishing pad uses a flexible base structure that can conform to non-planar substrate surfaces. This flexibility allows the pad to maintain uniform contact pressure across the substrate surface, preventing over-removal or under-removal of material in specific regions and protecting device integrity.
Solution Approach 2:
The system enables independent control of pressure and contact area parameters across different regions of the polishing pad. By adjusting these parameters dynamically, the system can compensate for substrate non-planarity and achieve uniform material removal while maintaining device integrity.
3Productivity
If polishing pad has large surface area for full substrate coverage, then overall polishing efficiency is improved, but local polishing control resolution is reduced
Solution Approach 1:
The polishing pad is divided into multiple independently controllable segments or regions. This segmentation allows the entire pad to maintain large surface area for full substrate coverage while enabling precise local control in each segment, thus achieving both high throughput and fine resolution local polishing control.
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 system provides improved local polishing control with precise material removal, reducing the risk of damage to devices and enhancing yield by conforming to non-planar substrates and distributing forces evenly.
Implementation Method 1
the flexible base expands and contracts based on pressure contained within the housing and a second side of the flexible base
Implementation Method 2
a flexible base coupled to the housing, and a contact region disposed on a first side of the flexible base
Implementation Method 3
Material is removed from the feature side of the substrate that is in contact with the polishing pad through a combination of chemical and mechanical activity
Implementation Method 4
Material is removed from the feature side of the substrate that is in contact with the polishing pad through a combination of chemical and mechanical activity
Data Source
AI summary
A polishing device includes a housing, a flexible base coupled to the housing, and a contact region disposed on a first side of the flexible base, wherein the flexible base expands and contracts based on pressure contained within the housing and a second side of the flexible base to form a contact area on the first side that is less than a surface area of the flexible base.