Multi-beam Writing Apparatus Modulation Rate Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for correcting positional and dimension deviations in multi-beam writing techniques are insufficient, leading to inaccuracies in pattern formation during semiconductor manufacturing.
Innovation Solution
A multi-charged particle beam writing apparatus and method that calculates and adjusts the beam dose for each pixel and its periphery using modulation rate maps to correct positional and dimension deviations, ensuring precise pattern formation by modulating the beam dose and distributing it across adjacent pixels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multi-beam writing is used to increase throughput, then productivity is improved, but manufacturing precision deteriorates due to beam positional deviation and pattern dimension deviation
Solution Approach 1:
The patent applies local quality by calculating and applying individual modulation rates for each pixel and its peripheral pixels based on their specific positional deviations. The modulation rate varies locally across the writing region to compensate for beam position errors, ensuring that each affected area receives the appropriate dose correction tailored to its specific deviation characteristics.
Solution Approach 2:
The patent changes the beam dose parameter dynamically by modulating it according to calculated modulation rates. The beam dose is adjusted pixel-by-pixel based on the measured positional deviations, transforming a fixed dose approach into a variable dose approach that compensates for optical distortion and beam position errors while maintaining high throughput multi-beam writing.
2Manufacturing precision
If beam dose is modulated to correct positional deviation, then manufacturing precision is improved, but device complexity increases due to additional calculation and control mechanisms
Solution Approach 1:
The patent applies preliminary action by pre-calculating the modulation rates for all pixels before actual pattern writing begins. The system measures beam positional deviations, computes the required dose modulations in advance, and stores these modulation rates for use during writing. This preliminary calculation phase separates the complex computational work from the writing execution, simplifying the real-time control requirements.
Solution Approach 2:
The patent introduces modulation rate maps as an intermediary data structure that bridges the gap between measured beam positions and required dose corrections. These maps serve as a pre-computed lookup table that simplifies the control mechanism during writing, allowing the system to apply corrections through simple map-based dose modulation rather than complex real-time calculations.
3Device complexity
If conventional correction methods are used, then device complexity is kept low, but manufacturing precision remains insufficient for accurate pattern formation
Solution Approach 1:
The patent extends the correction approach from a single-pixel focus to include peripheral pixels in the modulation rate calculation. By considering the spatial relationship between a pixel and its neighbors, the system accounts for dose distribution effects and optical distortion patterns across multiple pixels simultaneously, achieving more accurate correction without proportionally increasing system complexity.
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 corrects positional and dimension deviations, improving writing precision and accuracy, particularly at the pattern edges, and enhances the overall precision of the multi-beam writing process.
Implementation Method 1
a deflector, and configured to write a pattern on the target object with the multi charged particle beams such that each beam of the corrected dose irradiates a corresponding pixel
Data Source
AI summary
A multi charged particle beam writing apparatus includes a modulation rate data calculation processing circuitry to calculate, for each pixel being a unit region, a modulation rate of a beam to a pixel concerned and each modulation rate of a beam to at least one pixel at a periphery of the pixel concerned, and a corrected-dose calculation processing circuitry to calculate, for the each pixel, a corrected dose by adding a multiplied value obtained by multiplying the modulation rate of the pixel concerned in a modulation rate map by beam dose to the pixel concerned, and a multiplied value obtained by multiplying the modulation rate of the pixel concerned which becomes one of the at least one pixel at the periphery with respect to another pixel defined for the position of the pixel concerned by a beam dose to the another pixel.