Electron Beam Drift Correction via Dynamic Interval Adjustment
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Solution Overview
Problem
Existing electron beam lithography techniques face challenges in accurately correcting beam drift, particularly due to unpredictable initial drift rates and disturbances, which lead to increased correction operations and reduced throughput, and fail to effectively compensate for deflection sensitivity degradation and Z-sensor axis offsets.
Innovation Solution
A method that periodically corrects electron beam drift using variable time intervals and triggers additional corrections based on measured changes in disturbance factors such as atmospheric pressure and temperature, allowing for longer correction intervals and reducing the number of drift correction operations by aligning with actual drift directions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If recurrent beam drift correction is performed at frequent intervals to maintain pattern writing accuracy, then manufacturing precision is improved, but productivity deteriorates due to increased correction operations interrupting the pattern writing process
Solution Approach 1:
The system continuously monitors disturbance factors (temperature, pressure, humidity) and uses this feedback to predict when beam drift will occur, triggering correction only when necessary rather than at fixed intervals. This feedback mechanism allows the system to maintain accuracy while minimizing interruptions to pattern writing.
Solution Approach 2:
The correction interval is made dynamic rather than fixed. The system adjusts the timing and frequency of drift correction operations based on real-time environmental conditions and actual beam drift measurements, allowing longer intervals when conditions are stable and shorter intervals when disturbances are detected, thereby optimizing both accuracy and productivity.
2Device complexity
If beam drift correction is performed at fixed time intervals to simplify control, then device complexity is reduced, but manufacturing precision deteriorates because unpredictable initial drift rates and disturbances are not adequately compensated
Solution Approach 1:
The system incorporates disturbance factor monitoring and beam drift measurement feedback loops that detect actual drift conditions and trigger corrections when thresholds are exceeded. This feedback-based approach maintains high precision by responding to actual drift events rather than relying on fixed schedules, while keeping control logic relatively simple through threshold-based triggering.
Solution Approach 2:
The system performs preliminary measurements of disturbance factors (temperature, pressure, humidity) and beam drift to predict when corrections will be needed. By preparing correction data in advance and having it ready when drift exceeds thresholds, the system achieves high precision without requiring complex real-time control during pattern writing.
3Productivity
If the number of drift correction operations is reduced to improve throughput, then productivity is improved, but manufacturing precision deteriorates due to insufficient compensation for beam drift
Solution Approach 1:
The system uses disturbance factor monitoring to detect when environmental changes indicate potential beam drift, triggering corrections only when necessary. This feedback-based triggering reduces the number of unnecessary corrections while ensuring that all significant drift events are compensated, maintaining precision while improving throughput.
Solution Approach 2:
The system performs preliminary assessment of disturbance factors and beam drift magnitude before initiating correction operations. By evaluating whether drift exceeds correction thresholds, the system avoids unnecessary corrections that would reduce throughput while ensuring that all corrections performed are meaningful and maintain pattern position accuracy.
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 reduces the number of drift correction operations, enhances pattern depiction accuracy, and improves throughput by dynamically adjusting correction intervals and deflection sensitivity, effectively managing beam stability and disturbances.
Implementation Method 1
the electron beam being deflected to travel toward the workpiece
Implementation Method 2
irradiation onto a target workpiece... resulting in production of electrons as reflected therefrom
Data Source
AI summary
A method for correcting drifts of an electron beam, includes periodically correcting drift of the electron beam once per time period while varying the time period in length, and correcting, in addition to the correction per time period, the drift of the electron beam regardless of elapse of said time period when a change in value of a specified disturbance factor occurs with a prespecified change amount.