Semiconductor Wafer Processing Assembly with Weir Chemistry Collection
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Solution Overview
Problem
Existing semiconductor fabrication processes face challenges with contamination from copper ions diffusing into silicon substrates and unstable copper deposition at the bevel, leading to incomplete cleaning and chemical splash during processing, which affects the quality and efficiency of semiconductor wafer processing.
Innovation Solution
A processing assembly with a rotor assembly for spinning the workpiece and a chemistry collection assembly featuring a weir assembly to minimize masking and optimize chemistry collection, allowing for reduced splashing and improved recovery of spent chemistry, enabling comprehensive cleaning of semiconductor wafers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional cleaning chambers are used with masked areas on the wafer, then the wafer can be processed, but the wafer cannot be fully exposed to the cleaning chemistry, resulting in contamination
Solution Approach 1:
The patent employs a spin-driven dynamic cleaning process where the wafer rotates at high speed during cleaning. This dynamic motion allows the cleaning chemistry to fully access all wafer surfaces including previously masked areas, eliminating contamination while the wafer spins. The rotor assembly creates centrifugal forces that distribute chemistry uniformly across the wafer surface.
Solution Approach 2:
The cleaning chamber is segmented into distinct functional zones: a rotor assembly region for wafer spinning, a chemistry delivery region for reagent application, and a chemistry collection region with weir assemblies for spent chemistry removal. This segmentation allows each zone to optimize its function without interfering with others, enabling complete wafer exposure to cleaning chemistry.
2Object-affected harmful factors
If chemistry collection areas are not optimized, then the chamber structure is simpler, but chemical splash occurs resulting in contamination and undesirable etching
Solution Approach 1:
The weir assembly acts as an intermediary structure between the chemistry delivery zone and collection zone. These weirs function as barriers that control chemistry flow, preventing splashing and aerosol formation while directing spent chemistry into collection channels. The weir design includes angled surfaces that promote smooth chemistry transition without violent splashing.
Solution Approach 2:
The chemistry collection system utilizes hydraulic principles where spent chemistry flows under gravity along controlled paths defined by the weir assemblies. The system employs fluid dynamics to channel chemistry smoothly into collection areas, using flow velocity and pressure management to prevent aerosol generation and chemical splash during the collection process.
3Loss of substance
If chemistry collection is not optimized for recovery, then the collection system is simpler, but chemistry recovery and reuse is inefficient
Solution Approach 1:
The patent implements a chemistry recovery system where spent cleaning chemistry is collected in dedicated collection channels defined by the weir assemblies. Instead of discarding all chemistry, the system recovers and reuses viable cleaning solutions, reducing chemical consumption and waste. The collection channels are designed to separate spent chemistry from the processing environment while maintaining its utility for reuse.
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 solution effectively reduces contamination by ensuring thorough cleaning of all surfaces, including the bevel, and optimizes chemistry recovery, enhancing the efficiency and quality of semiconductor wafer processing.
Implementation Method 1
a rotor assembly capable of spinning a workpiece
Implementation Method 2
A typical copper cleaning solution for semiconductors is dilute sulfuric peroxide chemistry
Implementation Method 3
a chemistry collection assembly for collecting spent chemistry from the workpiece, wherein the chemistry collection assembly includes a weir assembly surrounding the rotor assembly
Data Source
AI summary
A processing assembly for a semiconductor workpiece generally includes a rotor assembly capable of spinning a workpiece, a chemistry delivery assembly for delivering chemistry to the workpiece, and a chemistry collection assembly for collecting spent chemistry from the workpiece. The chemistry collection assembly includes a weir assembly surrounding the rotor assembly and having a plurality of weirs. Methods for processing a semiconductor workpiece generally include moving at least one of the rotor assembly and the weir assembly.