Multi-Beam Writing Dose Correction for Defective Beam Skips
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Solution Overview
Problem
In multiple charged particle beam writing, excessive doses due to defective beams can lead to shape errors in patterns formed on target objects, and existing methods may result in unnecessary defect corrections when skipping regions without patterns, breaking the premise of correction and causing inefficiencies.
Innovation Solution
A multiple charged particle beam writing apparatus and method that includes a beam forming mechanism, dose data generation, dose determination, and pattern existence determination circuits to identify and correct excessive doses by skipping regions without patterns and redistributing doses across adjacent regions, ensuring accurate pattern formation while avoiding unnecessary corrections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple charged particle beams are used for writing, then writing throughput is greatly increased, but excessive doses from defective beams cause shape errors in patterns
Solution Approach 1:
The system performs preliminary detection of defective beams before the writing process. The detection unit identifies beams that may deliver excessive doses, and the control unit pre-calculates correction strategies by redistributing doses from defective beams to adjacent beams. This preliminary action prevents shape errors before they occur during pattern writing.
Solution Approach 2:
The system implements a feedback mechanism where the detection unit continuously monitors beam status, and the control unit adjusts the writing plan based on detected defects. When defective beams are identified, the system automatically redistributes their assigned doses to adjacent beams and updates the writing sequence, ensuring pattern accuracy is maintained despite beam failures.
2Productivity
If regions without patterns are skipped during writing, then writing efficiency is improved, but unnecessary defect corrections occur when defective beams are present in skipped regions
Solution Approach 1:
The control unit performs preliminary analysis to identify regions containing defective beams before the writing process begins. Even if these regions appear to contain no patterns, the system marks them for correction to prevent potential issues. This preliminary identification ensures that no unnecessary corrections occur during the writing process, maintaining writing efficiency.
Solution Approach 2:
The system applies different quality levels of correction based on local conditions. Regions with defective beams receive enhanced attention and correction, while regions without patterns and without defective beams are efficiently skipped. This localized quality approach ensures corrections are only performed where necessary, avoiding unnecessary time loss.
3Manufacturing precision
If defective beams are corrected by redistributing doses to adjacent beams, then pattern accuracy is maintained, but the complexity of the writing control system increases
Solution Approach 1:
The system segments the writing region into discrete units and handles dose redistribution at the beam level rather than requiring complex system-wide recalculations. Each defective beam's dose is independently redistributed to its adjacent beams, simplifying the control logic. This segmentation approach maintains pattern accuracy while reducing overall system complexity.
Solution Approach 2:
The control unit automatically detects defective beams and performs dose redistribution without external intervention. The system self-corrects by identifying which beams are defective and automatically reassigning their doses to adjacent beams, maintaining pattern accuracy through autonomous operation rather than requiring complex external control mechanisms.
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 effectively reduces excessive doses and avoids unnecessary defect corrections, ensuring precise pattern formation and efficient writing processes by accurately identifying and addressing defective beams and redistributing doses, thereby maintaining correction premises.
Implementation Method 1
a beam forming mechanism configured to form multiple charged particle beams
Implementation Method 2
deflects, by a deflector, a reduced beam to be applied to a desired position on a target object or 'sample'
Data Source
AI summary
A multiple charged particle beam writing apparatus includes a dose-data-for-defect-position-generation-circuit to generate dose-data-for-defect which defines a dose for a defect at the defect position when the dose of the nonzero value is defined in the vicinal region, and a writing mechanism to write patterns on a sample using multiple charged particle beams, wherein, when performing the writing, a unit region where writing processing is to be performed is moved to a next unit region where a pattern was determined to exist, skipping a unit region where no pattern was determined to exist by a pattern-existence-determination-circuit, and correction is performed to reduce an excessive dose, resulting from the defective beam at any writing pass in plural writing passes of multiple writing, at another writing pass.