Rotating Polishing Head for Wafer Surface Preparation
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Solution Overview
Problem
Current chemical mechanical polishing (CMP) methods for wafer surfaces are costly and require large installation spaces, consume abrasive materials, and pose contamination risks due to the need for slurry use, making them inefficient for removing fine protrusions and preparing surfaces for nanoimprint lithography.
Innovation Solution
A compact polishing apparatus using rotating polishing tools with abrasive grains, which oscillate and press against the wafer surface while supplying a liquid without abrasive grains, allowing for effective surface preparation without slurry, thus reducing contamination and costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a CMP apparatus is used to remove fine protrusions from the wafer surface, then the fine protrusions can be removed effectively, but the installation space required increases significantly
Solution Approach 1:
The invention divides the polishing function into multiple portable polishing heads that can be moved and repositioned as needed, rather than using a single large fixed polishing table. This segmentation allows the same polishing capability to be achieved in a much smaller footprint space.
Solution Approach 2:
The invention transitions from a two-dimensional large table topology to a three-dimensional movable head configuration, where polishing heads can be positioned at different heights and locations around the wafer, enabling effective polishing without requiring a large horizontal installation area.
2Manufacturing precision
If a CMP apparatus is used to polish the wafer surface, then fine protrusions can be removed, but consumable costs increase due to slurry and polishing pad usage
Solution Approach 1:
The invention replaces expensive consumables like slurry and polishing pads with a reusable polishing head system that uses minimal or no consumable materials, significantly reducing ongoing operational costs while maintaining polishing effectiveness.
Solution Approach 2:
The polishing head is designed to be self-contained with integrated abrasive elements that can be reused multiple times without requiring external slurry supply or pad replacement, making the system self-sufficient and eliminating continuous consumable costs.
3Manufacturing precision
If a CMP apparatus is used to polish the wafer surface, then fine protrusions can be removed, but contamination risk increases due to slurry residue
Solution Approach 1:
The invention extracts and eliminates the slurry component from the polishing process entirely, using a dry or liquid-free polishing mechanism that prevents contamination from slurry residue while still achieving effective removal of fine protrusions.
Solution Approach 2:
The invention converts the potential harm of slurry contamination into a benefit by using a polishing method that generates no slurry residue, thereby eliminating the need for extensive post-polishing cleaning while maintaining polishing effectiveness.
4Manufacturing precision
If a large diameter polishing table is used in the CMP apparatus, then polishing coverage is sufficient, but the device size and installation space increase
Solution Approach 1:
The invention segments the polishing function into multiple smaller polishing heads that can be positioned around the wafer, providing sufficient total polishing coverage without requiring a single large polishing table, thereby reducing the overall device footprint.
Solution Approach 2:
The polishing heads are designed to be multi-functional and can be repositioned to polish different areas of the wafer, providing universal coverage capability that replaces the need for a large fixed polishing table while maintaining adequate polishing coverage.
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 enables low-contamination, cost-effective polishing of wafer surfaces, preventing template damage and allowing for efficient removal of fine protrusions, thereby extending template lifespan and improving nanoimprint lithography processes.
Implementation Method 1
rotating a substrate while holding a back-side surface of the substrate with a vacuum suction stage
Data Source
AI summary
A polishing method capable of polishing a substrate, such as a wafer, with low running costs is disclosed. A polishing method includes: rotating a substrate while holding a back-side surface of the substrate with a vacuum suction stage; rotating a polishing head holding a plurality of polishing tools; and polishing a front-side surface of the substrate by pressing the plurality of polishing tools, which are rotating, against the front-side surface of the substrate. The front-side surface is a surface on which interconnect patterns are to be formed.