CMP Vacuum Head Integration for Pad Debris Removal
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Solution Overview
Problem
Existing chemical mechanical polishing (CMP) processes face issues with uneven surface topography leading to defects and inconsistent removal rates due to debris and polishing by-products accumulation on the polishing pad, which affect subsequent photolithographic processes.
Innovation Solution
A vacuum system is integrated into the CMP process to remove debris and polishing by-products from the polishing pad, enhancing the distribution of slurry and maintaining consistent removal rates by using a momentum vacuum assembly attached to the slurry dispenser and pad conditioner.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If CMP process is performed without vacuum system, then polishing can proceed continuously, but debris and polishing by-products accumulate on polishing pad causing uneven surface topography and inconsistent removal rates
Solution Approach 1:
The vacuum system is integrated with the slurry dispenser and pad conditioner by attaching the vacuum head to the slurry dispenser arm, allowing simultaneous slurry delivery and debris removal through a unified system structure
Solution Approach 2:
A vacuum head with suction capability is used to remove debris and polishing by-products from the polishing pad surface through pneumatic suction, preventing accumulation and maintaining uniform surface topography
2Manufacturing precision
If vacuum system is added to remove debris, then removal rate consistency improves, but system complexity and operational difficulty increase
Solution Approach 1:
The vacuum system is combined with the slurry dispenser arm, so that debris removal and slurry delivery occur simultaneously through a single integrated mechanism, simplifying operation compared to separate systems
Solution Approach 2:
The slurry dispenser arm is given multiple functions: delivering slurry to the polishing pad and simultaneously removing debris through the integrated vacuum head, reducing the need for separate operational mechanisms
3Productivity
If debris accumulates on polishing pad, then polishing continues without interruption, but surface defects such as dishing and scratches increase
Solution Approach 1:
The vacuum system operates continuously during the CMP process to remove debris and polishing by-products in real-time, ensuring consistent surface quality throughout the polishing operation without interruption
Solution Approach 2:
The vacuum head uses pneumatic suction to continuously remove debris from the polishing pad surface, preventing defect formation while maintaining polishing 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 vacuum system effectively reduces surface defects and improves removal rates by managing debris and by-products, minimizing defects such as dishing and scratches, and ensuring uniform polishing across the workpiece surface.
Implementation Method 1
A vacuum system is integrated into the CMP process to remove debris and polishing by-products from the polishing pad
Data Source
AI summary
A method includes depositing a slurry onto a polishing pad of a chemical mechanical polishing (CMP) station. A workpiece is polished and polishing by-products and slurry are removed from the polishing pad by a vacuum head. A CMP apparatus includes a polishing pad configured to rotate during a CMP process. The apparatus also includes a slurry dispenser configured to deposit a slurry onto a polishing surface of the polishing pad. The apparatus further includes a momentum vacuum assembly including a slotted opening facing the polishing surface of the polishing pad. The apparatus also includes a first suction line coupled to an upper portion of the momentum vacuum assembly and leading to a first vacuum source, the first suction line configured to transport polishing products which have been removed from the polishing pad through the slotted opening.