Multi-beam Writer Pattern Placement Error Compensation
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Solution Overview
Problem
Charged-particle multi-beam exposure apparatuses face challenges in achieving accurate pattern placement due to build-up effects such as electrostatic charging, magnetization, and thermo-mechanical deformation, leading to registration offsets that vary with local pattern density during the writing process.
Innovation Solution
A method is developed to compensate for registration errors by establishing a displacement behavior model based on local pattern density evolution, predicting placement errors, and repositioning beam field frames accordingly, using a beam deflection device to adjust their positions based on predicted values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multi-beam writing is used to increase productivity, then writing speed increases, but pattern placement accuracy deteriorates due to build-up effects
Solution Approach 1:
The patent applies preliminary action by calculating and storing displacement values for each beam field frame before the actual writing process. The displacement behavior model is established in advance based on local pattern density evolution, allowing the system to pre-determine correction values that will compensate for build-up effects during writing, thus maintaining placement accuracy while enabling high-speed multi-beam operation
Solution Approach 2:
The patent implements feedback through the displacement behavior model that continuously accounts for local pattern density evolution during the writing process. The system monitors the cumulative exposure dose and calculates corresponding displacement values, creating a closed-loop compensation mechanism that adjusts beam field frame positions in real-time to counteract build-up effects and maintain placement precision
2Manufacturing precision
If beam field frames are repositioned to compensate for placement errors, then pattern placement accuracy improves, but device complexity increases
Solution Approach 1:
The patent replaces complex mechanical repositioning mechanisms with a computational approach. Instead of physically adjusting beam field frame positions during writing, the system uses a displacement behavior model to calculate displacement values and applies these as corrective parameters in the writing data, substituting mechanical complexity with algorithmic processing while achieving the same compensation effect
Solution Approach 2:
The patent creates a virtual model of the displacement behavior that mirrors the actual build-up effects. By establishing a displacement behavior model that replicates the relationship between local pattern density and beam displacement, the system can predict and compensate for errors through data processing rather than direct physical intervention, simplifying the overall system architecture
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 compensates for registration offsets, ensuring high accuracy in pattern placement by accounting for the evolution of local pattern density over time, thereby improving the precision of pattern writing in charged-particle multi-beam exposure processes.
Implementation Method 1
using a beam deflection device to adjust their positions based on predicted values
Implementation Method 2
a layout is generated by exposing a plurality of beam field frames using a beam of electrically charged particles
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A method for compensating pattern placement errors during writing a pattern on a target in a charged-particle multi-beam exposure apparatus is presented. A layout is generated by exposing a plurality of beam field frames using a beam of electrically charged particles, wherein each beam field frame has a respective local pattern density, corresponding to exposure doses imparted to the target when exposing the respective beam field frames. During writing the beam field frames, the actual positions thereof deviate from their respective nominal positions by a placement error as a result of build-up effects within said exposure apparatus, depending on the local pattern density evolution during writing the beam field frames. To compensate this displacement, a displacement behavior model established beforehand is employed to predict the displacements; a local pattern density evolution is determined, displacements of the beam field frames are predicted based on the local pattern density evolution and the displacement behavior model, and the beam field frames are repositioned accordingly based on the predicted values.