Charged Particle Beam Lithography Multiple Exposure Passes

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Solution Overview

Problem

Charged particle beam lithography is time-consuming and costly due to the high number of shots required to form complex patterns on reticles and other surfaces, particularly for curvilinear patterns, and is limited by shot overlap and dosage constraints of existing systems.

Innovation Solution

The method involves using multiple exposure passes with different union sets of shots, allowing varying base dosage levels and shot outlines between passes, enabling reduced shot counts and increased dosage levels by overlapping shots across passes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If multiple exposure passes with different union sets of shots are used, then the number of shots needed to form complex patterns is reduced, but the system complexity increases

Engineering Contradiction:

Improvenumber of shots neededVSAvoidexposure pass coordination

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent divides the pattern formation process into multiple exposure passes, where each pass writes a different union set of shots. This segmentation allows the system to reduce the total number of shots needed while managing complexity through structured organization of exposure sequences.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent implements dynamic adjustment of shot outlines and base dosage levels between different exposure passes. By allowing these parameters to vary dynamically across passes rather than remaining static, the system achieves more efficient pattern formation with fewer total shots.

Inventive Principle:

Principle #15Dynamics

2Manufacturing precision

If varying base dosage levels and shot outlines are used between passes, then manufacturing precision is enhanced, but the process complexity increases

Engineering Contradiction:

Improvepattern accuracyVSAvoidexposure parameter control

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies different base dosage levels and shot outlines to different exposure passes based on local requirements of the pattern being formed. This local quality approach allows optimization of precision for specific pattern regions while managing overall process complexity through targeted parameter variation.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent systematically changes exposure parameters (base dosage levels, shot outlines) between different exposure passes. By controlling these parameter changes in a structured manner, the system enhances manufacturing precision while keeping process complexity manageable through deliberate parameter management.

Inventive Principle:

Principle #35Parameter changes

3Quantity of substance

If overlapping shots across passes are used, then dosage limitations are overcome, but the risk of overexposure increases

Engineering Contradiction:

Improvedosage levelVSAvoidoverexposure control

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The patent incorporates feedback mechanisms to monitor and control the cumulative dosage received by different regions of the pattern across multiple exposure passes. This feedback allows the system to overcome dosage limitations by enabling overlapping shots while maintaining reliability through active overexposure prevention.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent strategically applies partial overlapping of shots across exposure passes, using excessive action in specific regions where additional dosage is beneficial while avoiding overexposure in other regions. This selective approach allows the system to overcome dosage limitations without compromising reliability.

Inventive Principle:

Principle #16Partial or excessive action

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 reduces the number of shots needed to form complex patterns, enhances accuracy, and overcomes shot dosage limitations, thereby decreasing the time and cost associated with charged particle beam lithography.

Implementation Method 1

charged particle beam lithography is used to transfer patterns to a substrate

Methodology Applied

Scientific EffectCharged particle beam: Electron Beam

Data Source

PatentUS8137871B2Method and system for fracturing a pattern using charged particle beam lithography with multiple exposure passes which expose different surface area

Publication Date: 2012.03.20 D2S INC

AI summary

In the field of semiconductor production using charged particle beam lithography, a method and system for fracturing or mask data preparation or proximity effect correction is disclosed, in which the union of shots from one of a plurality of exposure passes is different than the union of shots from a different exposure pass. Methods for manufacturing a reticle and for manufacturing an integrated circuit are also disclosed, in which the union of shots from one of a plurality of charged particle beam exposure passes is different than the union of shots from a different exposure pass.