Batch Wafer Cleaning with Rotating Transfer for Etch Uniformity
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Solution Overview
Problem
Conventional batch wafer cleaning equipment leads to flow defects, dispersion uniformity issues, and varying etch rates across the wafer surface due to by-products accumulation and process distribution imbalances.
Innovation Solution
A wafer cleaning system comprising a processing bath group with multiple baths and wafer transferring units that rotate and move wafers between baths, ensuring uniform process distribution by adjusting the orientation of wafers during processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If batch equipment is used for wet cleaning, then multiple wafers can be cleaned simultaneously, but flow defects and deterioration of dispersion uniformity occur on the wafer
Solution Approach 1:
The wafer transferring unit rotates wafers at predetermined intervals during the cleaning process, dynamically changing their orientation relative to the chemical solution flow. This dynamic adjustment ensures uniform exposure to the cleaning solution across all wafer regions, eliminating flow defects and dispersion uniformity issues while maintaining batch processing capability
Solution Approach 2:
The system implements periodic rotation of wafers at specific time intervals during the cleaning process. This periodic action redistributes the chemical solution flow patterns across different wafer regions, preventing accumulation of by-products in specific areas and ensuring uniform cleaning performance across all simultaneously processed wafers
2Productivity
If batch equipment is used for wet cleaning, then processing efficiency is improved, but etch rate varies depending on wafer surface region
Solution Approach 1:
By dynamically rotating wafers during processing, the system ensures that all regions of each wafer receive equivalent exposure to the chemical solution. This dynamic orientation change eliminates regional variations in etch rate while preserving the high productivity benefits of batch processing
Solution Approach 2:
The system performs preliminary rotation actions at predetermined intervals to pre-distribute the chemical solution uniformly across wafer surfaces before the main cleaning action. This preliminary uniform distribution prevents regional etch rate variations from developing during the subsequent processing stages
3Device complexity
If wafers are stationary in processing baths, then equipment complexity is reduced, but by-products accumulate inside the processing bath
Solution Approach 1:
The wafer transferring unit introduces dynamic motion to wafers by rotating them at predetermined intervals. This simple rotational movement prevents by-product accumulation in processing baths by continuously refreshing the contact between the chemical solution and wafer surfaces, thereby maintaining reliable cleaning performance without significantly increasing equipment complexity
Data Source
AI summary
A wafer cleaning system comprising a processing bath group including a first Standard Clean (SC) processing bath, a first Hot Quick Dump Rinse (HQDR) processing bath and a second SC processing bath, which are disposed side by side in a first direction, and a first wafer transferring unit including a first rail guide extended in the first direction and a first driving unit on the first rail guide to move in the first direction along the first rail guide, and including a first arm configured to support the wafer group and rotate in a state that it supports the wafer group, and a second wafer transferring unit including a second rail guide extended in a second direction and a second driving unit mounted on the second rail guide to move in the second direction along the second rail guide, and including a support unit for supporting the wafer group.