Post-CMP Cleaning Apparatus with Brush Self-Cleaning
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Solution Overview
Problem
Conventional post-CMP cleaning processes are inadequate in effectively removing CMP residue from both surfaces of semiconductor wafers, leading to contamination and reduced cleaning quality due to the accumulation of residue on brushes, which can re-adhere to the wafers and require frequent replacement.
Innovation Solution
A post-CMP cleaning apparatus with a brush cleaner and inner tanks for self-cleaning, utilizing a first cleaning solution for scrubbing and a second cleaning solution for brush cleaning, along with adjustable brush positions and spray nozzles to ensure thorough residue removal and extended brush lifespan.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional brushes are used for post-CMP cleaning, then the cleaning process is simple, but the brushes accumulate residue and require frequent replacement
Solution Approach 1:
The brush cleaner is designed to clean itself by rotating within a cleaning solution bath, using its own motion to agitate and remove accumulated residue from its bristles. This self-cleaning mechanism eliminates the need for external manual cleaning operations and extends brush operational life between replacements.
Solution Approach 2:
The system performs preliminary cleaning of the brush by submerging it in a cleaning solution before the brush is used to clean wafers. This prevents residue accumulation that would otherwise occur during normal operation, maintaining brush effectiveness throughout its service life.
2Manufacturing precision
If brushes are used without self-cleaning, then the apparatus is simpler, but residue re-adheres to wafers reducing cleaning quality
Solution Approach 1:
The brush automatically cleans itself during operation by rotating in the cleaning solution, continuously removing residue that would otherwise transfer back to wafers. This maintains consistent cleaning quality throughout the brush's operational life and eliminates downtime for manual cleaning or replacement.
Solution Approach 2:
The brush cleaning action continues continuously during the brush's operational life through automatic rotation in the cleaning solution, rather than being a discrete periodic operation. This ensures the brush surface remains clean and effective for wafer cleaning throughout its service life.
3Manufacturing precision
If frequent brush replacement is performed, then cleaning quality is maintained, but fabrication costs increase
Solution Approach 1:
The brush cleaner performs automatic self-cleaning by rotating in a cleaning solution, removing residue that would otherwise degrade brush performance. This extends the operational life of each brush significantly, reducing the frequency of replacement and associated costs.
Solution Approach 2:
The system recovers cleaning effectiveness by continuously cleaning the brush in situ, rather than allowing the brush to degrade and requiring replacement. The cleaning solution acts as a recoverable medium that continuously restores brush cleaning capability.
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 apparatus effectively removes CMP residue from both wafer surfaces, maintains brush cleanliness, and extends the life of the brushes, improving the overall cleaning quality and reducing fabrication costs by preventing residue re-adherence and frequent brush replacement.
Implementation Method 1
a spray unit configured to apply a cleaning solution to the wafer
Implementation Method 2
a brush cleaner configured to scrub the wafer
Implementation Method 3
The relative movement of the polishing pad and the wafer surface coupled with the reactive chemicals in the slurry allows the CMP process to planarize or polish the wafer surface by means of both physical and chemical forces
Data Source
AI summary
Apparatuses and methods for performing a post-CMP cleaning are provided. The apparatus includes a chamber configured to receive a wafer in need of having CMP residue removed. The apparatus also includes a spray unit configured to apply a first cleaning solution to at least one surface of the wafer. The apparatus further includes a brush cleaner configured to scrub the at least one surface of the wafer. In addition, the apparatus includes at least one inner tank disposed in the chamber for storing a second cleaning solution that is used to clean the brush cleaner.