Multi-beam Writing Apparatus Shot Interval Correction
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Solution Overview
Problem
Multi-beam type writing apparatuses face challenges in achieving high precision due to field deformation in the optical system, leading to errors in pattern shape and size, making it difficult to write patterns with precision and requiring complex correction mechanisms that are time-consuming and burdensome.
Innovation Solution
A multi-charged particle beam writing apparatus with a stage, emitting unit, aperture member, blankers, deflector, and shot interval adjusting unit, which aligns beams on a target object and adjusts shot intervals to ensure alignment within a predetermined control grid interval, thereby correcting for field deformation and maintaining precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multi-beams are irradiated at a time to improve throughput, then productivity is improved, but field deformation occurs causing irradiation position deviations that worsen manufacturing precision
Solution Approach 1:
The patent applies preliminary action by pre-calculating and storing correction values for shot intervals in a correction value storage unit before actual writing. The system determines correction values based on beam positions and shot intervals in advance, then applies these corrections during writing operations. This allows the system to maintain high throughput with multi-beam irradiation while pre-compensating for field deformation effects, thereby resolving the contradiction between productivity and manufacturing precision.
2Manufacturing precision
If complex correction mechanisms are introduced to reduce field deformation, then manufacturing precision is improved, but device complexity increases and adjustment time is extended
Solution Approach 1:
The patent replaces complex mechanical correction mechanisms with a computational approach. Instead of using physical adjustment mechanisms to correct field deformation, the system calculates correction values based on beam positions and shot intervals, then applies these corrections through software control. This substitution of mechanical systems with computational methods reduces device complexity while maintaining manufacturing precision, directly addressing the contradiction between precision and complexity.
3Manufacturing precision
If shot interval is decreased to maintain pattern accuracy, then manufacturing precision is improved, but the shot interval becomes insufficient due to field deformation, making it difficult to achieve alignment
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting shot intervals based on calculated correction values. The system determines appropriate shot intervals considering field deformation effects, beam positions, and pattern requirements. By changing the shot interval parameter adaptively rather than using fixed intervals, the system maintains both pattern shape accuracy and beam alignment precision, resolving the contradiction between these two precision requirements.
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
The solution effectively suppresses variations in pattern shape or size caused by beam position deviations, allowing for high-precision pattern writing by adjusting shot intervals and beam alignment, reducing the complexity and time required for corrections.
Implementation Method 1
an electron beam emitted from an electron gun passes through a mask having a plurality of holes to form the multi-beams
Implementation Method 2
a deflector configured to deflect the beams together, which have passed through the blanking aperture member, at each irradiation position of each beam on the target object
Implementation Method 3
a blanking aperture member configured to shield each of the beams deflected by the plurality of blankers so that the beams deflected by the plurality of blankers are beam-off
Data Source
AI summary
In accordance with one aspect of this invention, a multi charged particle beam writing apparatus includes an aperture member, in which a plurality of openings are formed, configured to form multi-beams by making portions of the charged particle beam pass through the plurality of openings; a writing processing control unit configured to control writing processing so that a plurality of beams having passed through different openings among the plurality of openings are arranged to align on the target object; and a shot interval adjusting unit configured to adjust shot intervals among beams so that a maximum shot interval among beams being a control grid interval defined by a predetermined quantization size or a size which is prescribed within a predetermined range from the predetermined quantization size, or less when the shot intervals among beams which are arranged to align on the target object are different depending on a place.