Non-contact Pad Cleaning Apparatus for Semiconductor Polishing
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Solution Overview
Problem
The accumulation of foreign matter in the polishing surface of a polishing pad during the polishing process leads to scratches on the workpiece and contamination of cleaning tools, which can cause defects in semiconductor devices.
Innovation Solution
A non-contact pad cleaning apparatus using a plurality of two-fluid nozzles arranged along the radial direction of the polishing pad, with outlet ports inclined to match the rotation direction and increasing angles and distances from the center, combined with a liquid-removing fluid system to wash away foreign matter without direct contact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a jet of pure water is applied to the polishing surface to remove foreign matter from holes, then foreign matter is washed away from the holes, but foreign matter adheres to the polishing surface again and cannot be completely removed
Solution Approach 1:
The cleaning function is divided into two distinct stages: first, a jet of pure water removes foreign matter from the holes; second, a flow of liquid (without gas mixture) prevents foreign matter from adhering to the polishing surface. This segmentation of cleaning functions ensures complete foreign matter removal without re-adhesion.
Solution Approach 2:
The system performs preliminary cleaning by removing foreign matter from holes before addressing surface adhesion. By sequentially applying the jet flow first and then the liquid flow, the system prepares the surface in advance to prevent foreign matter accumulation during polishing.
2Area of stationary object
If the polishing pad has a large area, then it can cover the workpiece effectively, but foreign matter accumulates on the surface and causes scratches
Solution Approach 1:
The system extracts foreign matter from both the holes and the surface of the large-area polishing pad. By applying flows that target both hidden (holes) and visible (surface) accumulation areas, the system removes harmful foreign matter from the entire polishing surface regardless of its large area.
Solution Approach 2:
A flow of liquid acts as an intermediary medium to prevent foreign matter from adhering to the polishing surface. This liquid flow mediates between the polishing process and the surface, continuously removing foreign matter and preventing scratches on the workpiece.
3Manufacturing precision
If the dresser scrapes off the polishing surface to regenerate it, then the polishing surface is renewed, but foreign matter in the holes cannot be completely removed
Solution Approach 1:
The system replaces mechanical scraping (dresser) with a fluid-based cleaning system (jet of pure water followed by liquid flow). This substitution allows foreign matter to be removed from holes through fluid dynamics rather than mechanical contact, achieving complete removal without compromising surface regeneration.
Solution Approach 2:
The system uses hydraulic principles by applying a jet of pure water followed by a liquid flow to remove foreign matter from holes. This fluid-based approach complements the mechanical dresser operation, ensuring holes are cleaned effectively while the surface is being regenerated.
4Productivity
If foreign matter remains on the polishing pad, then the polishing process continues, but scratches are caused on the workpiece and contamination occurs
Solution Approach 1:
The system maintains continuous cleaning action during the polishing process. By continuously applying the jet of pure water and liquid flow, foreign matter is constantly removed from both holes and surface, preventing scratches and contamination while maintaining uninterrupted polishing productivity.
Solution Approach 2:
A flow of liquid serves as a continuous intermediary that prevents contact between foreign matter and the workpiece. This liquid barrier mediates the interaction between the polishing pad and workpiece, eliminating scratches and contamination while allowing the polishing process to continue without interruption.
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
Effectively removes foreign matter from the polishing pad surface, preventing scratches and contamination, thereby enhancing the quality of the polishing process and reducing defects in semiconductor devices.
Implementation Method 1
a jet of liquid-removing fluid to guide liquid contained in a two-fluid on the polishing surface of the polishing pad
Implementation Method 2
a plurality of two-fluid nozzles... having outlet ports which are inclined obliquely
Implementation Method 3
the turntable configured to rotate the polishing pad
Data Source
AI summary
A non-contact pad cleaning apparatus capable of removing foreign matter from minute holes formed in a polishing surface of a polishing pad is disclosed. The non-contact pad cleaning apparatus includes: a turntable configured to rotate the polishing pad; a plurality of two-fluid nozzles disposed above the polishing pad; and a liquid supply line and a gas supply line coupled to the plurality of two-fluid nozzles. The plurality of two-fluid nozzles are arranged along a radial direction of the polishing pad. The plurality of two-fluid nozzles have outlet ports which are inclined obliquely with respect to a reference line extending in the radial direction of the polishing pad when viewed from a direction perpendicular to the polishing surface of the polishing pad.