Polishing Tape Conditioning to Prevent Abrasive Particle Contamination
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Solution Overview
Problem
During the polishing of semiconductor wafers, abrasive particles from polishing tapes tend to fall off, contaminating the surface and causing defects, especially at higher rotating speeds, as they move towards the center, potentially damaging the semiconductor layer.
Innovation Solution
A polishing apparatus with a conditioning apparatus that preprocesses the polishing tape to remove loosely adherent abrasive particles using cleaning brushes, fluid blowing, suction, or adhesive contact, and a surface protection system to prevent fallen particles from entering the central device area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a polishing tape with abrasive particles is used to polish the peripheral portion of a semiconductor wafer, then the peripheral portion can be polished effectively, but abrasive particles fall off the polishing tape and contaminate the pure water and the central surface of the wafer
Solution Approach 1:
The patent applies preliminary action by pre-conditioning the polishing tape before actual polishing to remove loosely adherent abrasive particles. The conditioning apparatus prepares the tape in advance, and the process follows a specific sequence: conditioning → polishing → rinsing, where harmful actions are performed before useful actions to prevent contamination during the main polishing operation
Solution Approach 2:
The patent extracts the harmful abrasive particles from the system by using a suction device to remove fallen particles from the pure water and a shielding tool to prevent particles from reaching the central surface. This separates the harmful elements from the useful polishing process
2Productivity
If the rotating speed of the semiconductor wafer is increased to improve polishing efficiency, then productivity increases, but abrasive particles are more easily contaminated into the pure water and move toward the center of the wafer
Solution Approach 1:
The patent introduces intermediary elements (shielding tool and suction device) between the polishing process and the central wafer surface/pure water system. These intermediaries capture and remove abrasive particles that would otherwise contaminate the high-speed rotation environment, allowing efficient polishing without compromising surface cleanliness
Solution Approach 2:
The patent implements feedback control by continuously monitoring and removing abrasive particles during the polishing process. The suction device actively removes particles from the pure water, and the shielding tool prevents particle migration to the center, creating a closed-loop system that maintains cleanliness despite high-speed operation
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 prevents abrasive particles from falling off during polishing, maintaining a cleaner surface and protecting the central device area from contamination, thereby ensuring a defect-free polishing process.
Implementation Method 1
a conditioning apparatus for conditioning a surface of the polishing tape in order to prevent the abrasive particles from falling off the surface of the polishing tape during polishing
Implementation Method 2
fluid blowing, suction, or adhesive contact
Implementation Method 3
fluid blowing, suction, or adhesive contact
Implementation Method 4
fluid blowing, suction, or adhesive contact
Data Source
AI summary
A polishing apparatus can effectively prevent abrasive particles from falling off a polishing tape during polishing. The polishing apparatus includes: a polishing head for polishing a peripheral portion of a substrate by pressing a surface of a polishing tape, having abrasive particles fixed on the surface, against the peripheral portion of the substrate while allowing the polishing tape to travel in one direction; and a conditioning apparatus, disposed upstream of the polishing head in the traveling direction of the polishing tape, for conditioning the surface of the polishing tape in advance in order to prevent the abrasive particles from falling off the surface of the polishing tape during polishing.