Lithography Drain Cup Contamination Sensing and Solvent Cleaning
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Solution Overview
Problem
The lithography process in semiconductor manufacturing is hindered by contamination from solidified photoresist residue in the drain cup structure, which can clog ventilation systems, leading to reduced productivity and yield.
Innovation Solution
A sensor and flow meter system monitors contamination levels, triggering solvent dispensing to decontaminate the drain cup structure dynamically, ensuring timely cleaning and maintaining ventilation efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If manual maintenance and cleaning schedules are used, then contamination is eventually removed, but productivity is reduced due to unnecessary maintenance interruptions
Solution Approach 1:
The system employs sensors (optical, acoustic, or mass flow sensors) that continuously monitor contamination levels in the drain cup structure and provide feedback to the controller. The controller adjusts cleaning operations based on actual contamination levels, triggering solvent dispensing only when contamination thresholds are exceeded, thereby eliminating unnecessary maintenance interruptions while ensuring contamination is removed when needed.
Solution Approach 2:
The lithography apparatus performs its own maintenance through an automated cleaning system. When sensors detect contamination levels exceeding predefined thresholds, the controller automatically triggers solvent dispensing through dispensing structures, and the system self-regulates the cleaning process without external intervention, maintaining both reliability and productivity.
2Reliability
If frequent cleaning is performed, then contamination is consistently removed, but resource consumption and operational time increase
Solution Approach 1:
Instead of continuous or fixed-schedule cleaning, the system implements periodic cleaning actions triggered only when sensors detect contamination levels exceeding predefined thresholds. This demand-based periodic cleaning maintains reliability by cleaning when necessary while minimizing operational time loss by avoiding unnecessary cleaning cycles.
Solution Approach 2:
The system dynamically adjusts cleaning parameters based on contamination levels. Sensors monitor contamination and trigger cleaning operations only when contamination thresholds are exceeded, changing the cleaning frequency parameter from fixed to variable based on actual contamination conditions, thereby reducing unnecessary cleaning time while maintaining cleanliness standards.
3Device complexity
If no monitoring system is used, then device complexity is reduced, but contamination detection precision deteriorates
Solution Approach 1:
The system replaces manual inspection and mechanical monitoring with sensor-based detection systems. Optical sensors, acoustic sensors, or mass flow sensors automatically detect contamination levels with high precision, substituting complex manual monitoring procedures with automated sensor systems that provide precise measurement without requiring complex operational interventions.
Solution Approach 2:
Sensors serve as intermediary devices between the contamination source and the control system. These sensors detect contamination levels and transmit information to the controller, enabling precise contamination monitoring without requiring direct human intervention or complex mechanical inspection systems, thus achieving measurement precision with manageable system complexity.
4Productivity
If continuous operation is maintained, then productivity is maximized, but contamination accumulation increases
Solution Approach 1:
Sensors continuously monitor contamination levels during operation and provide feedback to the controller. When contamination thresholds are exceeded, the system automatically triggers cleaning operations, enabling continuous productivity while preventing harmful contamination accumulation through real-time feedback-based intervention.
Solution Approach 2:
The system converts the harmful effect of contamination accumulation into a useful trigger for cleaning operations. Sensors detect contamination levels and use this information to automatically initiate cleaning when needed, transforming the presence of contamination from a purely harmful factor into a beneficial signal that triggers necessary maintenance, thereby maintaining both productivity and cleanliness.
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
This approach prevents unnecessary maintenance, balances yield and productivity by ensuring continuous operation and effective removal of contaminants, thus enhancing the reliability of the lithography process.
Implementation Method 1
determining a contamination characteristic of the lithography apparatus by measuring a visual signature, an optical signature, an acoustic signature, a vacuum signature, or a material usage signature
Implementation Method 2
determining a contamination characteristic of the lithography apparatus by measuring a visual signature, an optical signature, an acoustic signature, a vacuum signature, or a material usage signature
Implementation Method 3
determining a contamination characteristic of the lithography apparatus by measuring a visual signature, an optical signature, an acoustic signature, a vacuum signature, or a material usage signature
Implementation Method 4
triggering a decontamination process to remove the residue associated with the one or more coating materials
Implementation Method 5
spraying the dispensed solvent to the drain cup structure and/or the ventilation conduit
Implementation Method 6
spinning the substrate to provide a centrifugal force to spray the dispensed solvent
Data Source
AI summary
The present disclosure describes a lithography apparatus comprising a photoresist coating unit configured to perform one or more coating processes on a substrate. The lithography apparatus further comprises a detection unit configured to determine a contamination level of a contaminant from the one or more coating processes adheres on a sidewall of the lithography apparatus. The lithography apparatus further comprises a controller unit configured to adjust one or more operations of the lithography apparatus based on a comparison between the contamination level and a baseline cleanliness requirement of the lithography apparatus.