Multi-Charged Particle Beam Blanking Apparatus for Coulomb Effect Suppression
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Solution Overview
Problem
In multi-beam writing techniques, increasing current density to enhance throughput leads to image blur and positional deviation due to the Coulomb effect, and existing methods struggle to individually control beam doses and timing effectively.
Innovation Solution
A multi-charged particle beam exposure method and apparatus that transmit ON/OFF control signals in batches to a blanking apparatus with individual blanking mechanisms, allowing each beam to be deflected and irradiated independently, while grouping beams to shift irradiation timing and reduce the Coulomb effect.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If current density is increased to improve writing throughput, then productivity increases, but image blur and positional deviation occur due to the Coulomb effect
Solution Approach 1:
The patent segments the multi-beam irradiation process into multiple shots by introducing a shot signal that divides beams into different groups. Each group is irradiated in separate shots with different timing, which reduces the total current amount in each shot and suppresses the Coulomb effect while maintaining high throughput through parallel processing of multiple beams
Solution Approach 2:
The patent implements periodic action by using shot signals to create distinct irradiation phases. Beams are divided into groups that are irradiated in alternating shots (odd shots and even shots), allowing the system to maintain high average throughput while each individual shot uses reduced current density to avoid the Coulomb effect
2Manufacturing precision
If beam arrays are grouped and irradiation timing is shifted to reduce the Coulomb effect, then manufacturing precision improves, but the number of control signal transmissions doubles and exposure time increases
Solution Approach 1:
The patent merges the control of multiple beams into a unified batch transmission system. All ON/OFF control signals for multiple beams are transmitted in a single batch operation, and the blanking apparatus processes them simultaneously using parallel blanking mechanisms, which eliminates the need for repeated sequential transmissions and maintains efficient exposure timing
3Manufacturing precision
If individual beam control is implemented in the blanking aperture array apparatus, then manufacturing precision improves, but device complexity increases
Solution Approach 1:
The patent implements a universal control architecture where a single control circuit in the blanking aperture array apparatus handles control signals for multiple beams through batch processing. The same control circuit processes ON/OFF signals for all beams in parallel, eliminating the need for separate control circuits for each beam and maintaining device simplicity while achieving individual beam control capability
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 inhibits the Coulomb effect and maintains throughput by allowing precise control of each beam's irradiation, reducing image blur and positional deviation, and eliminating the need for double exposure time cycles.
Implementation Method 1
a blanking apparatus in which there are mounted a substrate where a plurality of passage holes are formed to let a corresponding beam of the multi-beams individually pass therethrough, and a plurality of individual blanking mechanisms arranged in the substrate to individually perform blanking deflection of each beam of the multi-beams
Implementation Method 2
when increasing the current density, there is a problem in that a so-called blur and/or positional deviation of a multi-beam image occurs due to the Coulomb effect, depending on a total current amount of simultaneously irradiating multi-beams
Data Source
AI summary
A multi charged particle beam exposure method includes transmitting ON/OFF control signals each being an ON/OFF control signal for a corresponding beam of multi-beams of charged particle beams in a batch to a blanking apparatus in which there are mounted a substrate where a plurality of passage holes are formed to let a corresponding beam of the multi-beams individually pass therethrough, and a plurality of individual blanking mechanisms arranged in the substrate to individually perform blanking deflection of each beam of the multi-beams, and irradiating the substrate with the multi-beams in accordance with the ON/OFF control signals transmitted in a batch, while shifting an irradiation timing for each group obtained by grouping the multi-beams into a plurality of groups by a plurality of individual blanking mechanisms mounted in the blanking apparatus.