Electron Beam Deflection Correction for Stage Movement Delay
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Solution Overview
Problem
Existing electron beam image acquisition systems face challenges in maintaining accurate beam deflection position alignment during stage movement, leading to image deviation due to delay in beam deflection control, which affects the precision of pattern inspection in semiconductor manufacturing.
Innovation Solution
An electron beam image acquisition apparatus and method that includes a deflector, a deflection control system, a measurement circuitry to calculate deflection control delay time, and a correction circuitry to correct the beam deflection position, ensuring accurate image acquisition by synchronizing the beam deflection with the stage position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If beam deflection control is performed during stage movement, then image acquisition is enabled, but beam deflection position deviation occurs due to control delay
Solution Approach 1:
The system pre-calculates the beam deflection position based on stage position information before actual beam deflection occurs. By anticipating the required deflection position in advance and accounting for the predetermined time delay in the deflection control system, the correction amount is prepared beforehand to compensate for the delay, ensuring accurate beam positioning despite control lag
Solution Approach 2:
The system continuously acquires stage position information and uses it to calculate real-time correction amounts for beam deflection. This closed-loop feedback mechanism dynamically adjusts the beam deflection position based on actual stage movement, compensating for control delays and maintaining positioning accuracy throughout the scanning process
2Manufacturing precision
If beam deflection position is corrected in real-time, then image accuracy is improved, but system complexity increases
Solution Approach 1:
The system introduces a correction amount calculation unit as an intermediary component that processes stage position information and generates correction values. This intermediary layer sits between the stage position sensor and the beam deflection controller, performing mathematical calculations to determine the necessary correction without requiring complex hardware modifications to the existing deflection control system
Solution Approach 2:
The system replaces complex mechanical positioning adjustments with computational correction. Instead of modifying the physical deflection control mechanism to eliminate delay, the invention uses software-based calculation to determine correction amounts, substituting mechanical complexity with mathematical processing that achieves the same positioning 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 solution effectively inhibits beam deflection position deviation, enhancing the accuracy of pattern inspection and improving the yield in semiconductor manufacturing by ensuring precise alignment and correction of beam deflection delays.
Implementation Method 1
a deflector configured to deflect an electron beam
Implementation Method 2
measuring while moving a stage for placing thereon a substrate on which a figure pattern is formed, an edge position of a mark pattern arranged on the stage by scanning the mark pattern with an electron beam
Data Source
AI summary
An electron beam image acquisition apparatus includes a deflector to deflect an electron beam, a deflection control system to control the deflector, a measurement circuitry to measure, while moving a stage for placing thereon a substrate on which a figure pattern is formed, an edge position of a mark pattern arranged on the stage by scanning the mark pattern with an electron beam, a delay time calculation circuitry to calculate, using information on the edge position, a deflection control delay time which is a delay time to start deflection control occurring in the deflection control system, a correction circuitry to correct, using the deflection control delay time, a deflection position of the electron beam, and an image acquisition mechanism to include the deflector and acquire an image of the figure pattern at a corrected deflection position on the substrate.