Custom Wet Processing Control for Uniform Wafer Regions
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Solution Overview
Problem
Wet chemical processing of semiconductor wafers often results in non-uniformity due to varying replenishing rates of chemical solutions and structural variations across the wafer, leading to reduced chemical reaction rates and low device yield.
Innovation Solution
A wafer processing system that measures wafer characteristics, determines a wafer profile, and adjusts wet processing parameters, including nozzle angle and scanning speed, to customize chemical dispensation and ensure uniform processing across the wafer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If uniform wet processing parameters are used across the entire wafer, then the processing system is simple to operate, but processing uniformity deteriorates due to varying replenishing rates and structural variations across different wafer regions
Solution Approach 1:
The patent applies local quality by dividing the wafer into multiple regions (e.g., center, middle, peripheral regions) and assigning different wet processing parameters to each region based on its specific characteristics. The nozzle system adjusts chemical dispensation parameters locally for each region rather than using uniform parameters across the entire wafer, thereby achieving improved processing uniformity while managing system complexity through regional customization.
2Manufacturing precision
If the nozzle dispenses chemical solutions at constant speed and angle, then the operation is simple, but processing uniformity deteriorates due to varying replenishing rates across different wafer regions
Solution Approach 1:
The patent implements dynamics by making the nozzle parameters dynamic rather than static. The nozzle angle and scanning speed are adjusted dynamically based on the specific region being processed and the local wafer characteristics. This dynamic adjustment allows the system to optimize chemical replenishing rates for each region, achieving processing uniformity while the system automatically manages the complexity of parameter variations.
Solution Approach 2:
The system employs feedback mechanisms where wafer characteristics are measured and analyzed to determine regional profiles, which then feed back into the control system to adjust nozzle parameters accordingly. This closed-loop feedback enables automatic adaptation of processing parameters to achieve uniform results across different wafer regions without requiring manual intervention for each region's optimization.
3Productivity
If conventional wet processing is used without regional customization, then device yield is low due to non-uniform processing, but implementing regional customization increases system complexity
Solution Approach 1:
The patent applies segmentation by dividing the wafer processing into distinct regional segments (center, middle, peripheral regions) with customized processing parameters for each segment. This segmentation approach targets the root cause of non-uniform processing by treating different regions independently, thereby improving device yield through region-specific optimization while the automated system manages the complexity of multiple parameter sets.
Data Source
AI summary
Embodiments of wet processing systems and methods for uniform wet processing are disclosed. A method described in the present disclosure includes measuring one or more wafer characteristics of a wafer using a plurality of detectors and determining a wafer profile of the wafer based on the measured one or more wafer characteristics. The method also includes setting first and second sets of wet processing parameters of a wet processing system for respective first and second wafer regions based on the wafer profile, where a value of at least one wet processing parameter is different between the first and second sets of wet processing parameters. The method further includes performing wet processing on the wafer by dispensing one or more chemicals onto the first and second wafer regions according to the respective first and second sets of wet processing parameters.