Semiconductor Wafer Cleaning Tray with Rotating Drain System
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Solution Overview
Problem
Current wet bench and single wafer cleaning technologies face challenges in efficiently recycling or reclaiming cleaning solutions without cross-contamination, especially as wafer sizes increase and technology nodes advance, leading to reduced cleaning efficiency and shorter solution lifetimes.
Innovation Solution
A rotating tray with a drain outlet system that aligns with multiple receptors allows for precise collection and recycling of cleaning solutions, minimizing cross-contamination by using a motor-driven rotation mechanism and air-inflated seals to manage the flow of cleaning solutions and DI water, enabling efficient separation and reuse of cleaning agents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single wafer cleaning equipment processes one wafer at a time with multiple cleaning solutions in one chamber, then cross-contamination between cleaning solutions occurs, but the cleaning chamber size cannot be increased to separate solutions
Solution Approach 1:
The cleaning chamber is segmented into multiple isolated zones (first cleaning zone, second cleaning zone, rinsing zone) that are separated by a partition wall. Each zone can hold different cleaning solutions without cross-contamination, allowing multiple cleaning solutions to be used in sequence within the same chamber volume.
Solution Approach 2:
The tray structure is nested within the cleaning chamber, with the tray itself containing multiple recessed regions (first recessed region, second recessed region) that hold different cleaning solutions. This nested arrangement allows multiple cleaning solutions to be stored in a compact configuration without requiring a larger chamber.
2Productivity
If wet bench equipment processes batches of wafers sequentially through multiple baths, then cleaning efficiency is limited by low flow velocity, but increasing flow velocity increases process variation
Solution Approach 1:
The system dynamically adjusts the rotation speed of the wafer carrier based on the specific cleaning step being performed. Different rotation speeds are used for different cleaning zones, allowing optimization of cleaning efficiency for each step while maintaining consistent process parameters. The motor controller enables precise speed regulation to match process requirements.
Solution Approach 2:
The cleaning process operates continuously as the wafer carrier rotates through multiple zones without stopping between cleaning steps. The wafer undergoes sequential cleaning, rinsing, and drying in a continuous circular path, eliminating queue time and transfer delays between separate baths while maintaining controlled flow velocities in each zone.
3Loss of substance
If cleaning solutions are recycled without separation, then cost reduction is achieved, but cross-contamination reduces solution lifetime
Solution Approach 1:
The solution recovery system segments different cleaning solutions into separate recovery channels. The first cleaning solution is recovered through a first solution recovery channel, while the second cleaning solution is recovered through a second solution recovery channel, preventing cross-contamination during recycling and extending solution lifetime.
Solution Approach 2:
The partition wall extracts and isolates different cleaning solutions from each other within the same cleaning chamber. By physically separating the first and second cleaning zones, the system enables independent recovery and reuse of each cleaning solution without contamination from other solutions.
Data Source
AI summary
An apparatus for cleaning and conditioning the surface of a semiconductor substrate such as wafer includes a rotatable chuck, a chamber, a rotatable tray for collecting cleaning solution with one or more drain outlets, multiple receptors for collecting multiple cleaning solutions, a first motor to drive chuck, and a second motor to drive the tray. The drain outlet in the tray can be positioned directly above its designated receptor located under the drain outlet. The cleaning solution collected by the tray can be guided into designated receptor. One characteristic of the apparatus is having a robust and precisely controlled cleaning solution recycle with minimum cross contamination.