Wafer Wet Process Control for Over-Etch Rescue
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Solution Overview
Problem
In semiconductor manufacturing, wet processing operations such as etching and rinsing can lead to over-etching or over-dipping issues if wafers are not removed from the processing baths within predetermined times, resulting in damage to the semiconductor substrates.
Innovation Solution
A method and system for automatically controlling wet etch/rinse apparatuses, which include a wafer rescuing process. This process involves determining if a wafer is still in the processing bath after a pre-set time, and if so, draining the etching or rinsing solution and purging the bath to prevent further processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If wafers are kept in processing baths for extended periods to ensure complete processing, then processing quality improves, but over-etching and over-dipping damage occurs
Solution Approach 1:
The system uses sensors to detect wafer presence in the processing bath and provides feedback to the control system. When the wafer is detected to have been processed for the predetermined time period, the system automatically triggers the removal mechanism, ensuring precise timing without manual intervention or over-processing.
Solution Approach 2:
The system is designed to automatically monitor and remove wafers based on predetermined time parameters without requiring continuous human oversight. The automated control system manages the entire process from immersion to removal, enabling the process to self-regulate and prevent over-processing.
2Adaptability or versatility
If manual monitoring and removal of wafers is used, then flexibility in processing is maintained, but human error and timing inconsistencies lead to substrate damage
Solution Approach 1:
The patent replaces manual mechanical monitoring and removal operations with an automated control system that uses sensors and programmable logic to detect wafer presence and trigger removal at precise intervals, eliminating human timing errors while maintaining process flexibility through programmable parameters.
Solution Approach 2:
The system pre-sets the processing time parameters and automatically initiates the removal sequence when the predetermined time period elapses. This preliminary configuration of timing parameters ensures consistent, reliable processing without requiring real-time human judgment, while the system remains adaptable to different processing requirements through reprogramming.
3Manufacturing precision
If automated timing systems are implemented, then processing consistency improves, but system complexity increases
Solution Approach 1:
The patent extracts the critical timing and monitoring functions from the overall wet processing system, implementing a dedicated automated control subsystem that specifically handles wafer presence detection and timed removal. This modular approach improves processing consistency while containing the complexity increase to a specific functional module rather than the entire system.
Data Source
AI summary
A method includes placing a wafer in a process bath filled with a process solution; determining whether the wafer is in the process bath after a pre-set process time after placing the wafer in the process bath; and in response the determination determines that the wafer is in the process bath after the pre-set process time, draining the process solution from the process bath while the wafer is in the process bath.