Stage Speed Control for Resist Heating in Multi-Beam Writing

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Solution Overview

Problem

The challenge in multiple charged particle beam writing is the uncorrectable degradation of CD accuracy and resist alteration due to resist heating, which occurs when suppressing substrate temperature increase, leading to throughput degradation.

Innovation Solution

A method and apparatus that store relation data between stage speed, dose, and resist temperature increase, allowing for the determination of optimal stage speed and multiplicity to maintain an allowable temperature increase during writing, thereby preventing resist degradation while maximizing throughput.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If writing processing is performed with multiple charged particle beams to increase throughput, then productivity is improved, but temperature increase of resist occurs causing CD accuracy degradation and resist alteration

Engineering Contradiction:

Improvewriting throughputVSAvoidCD accuracy

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies parameter changes by dynamically adjusting stage speed and writing multiplicity based on pre-stored relation data. The system selects optimal combinations of stage speed (Vstage) and multiplicity (N) from stored data that satisfy temperature constraints, thereby maintaining CD accuracy while maximizing throughput through parameter optimization rather than fixed settings

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent implements preliminary action by pre-calculating and storing relation data among stage speed, dose, and temperature increase before actual writing processing. This allows the system to quickly determine optimal writing conditions without real-time temperature measurement, enabling proactive control of temperature rise while maintaining high throughput

Inventive Principle:

Principle #10Preliminary action

2Manufacturing precision

If stage speed is reduced to suppress temperature increase of resist, then manufacturing precision is improved, but writing throughput deteriorates

Engineering Contradiction:

ImproveCD accuracyVSAvoidwriting throughput

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

The patent applies dynamics by making stage speed variable rather than fixed. The system dynamically adjusts stage speed based on the selected combination from stored relation data, allowing optimization of both temperature control and throughput for different writing patterns and conditions, rather than using a constant conservative speed

Inventive Principle:

Principle #15Dynamics

3Productivity

If multiplicity of multiple writing is increased to improve throughput, then productivity is improved, but temperature increase of resist exceeds allowable range causing resist degradation

Engineering Contradiction:

Improvewriting throughputVSAvoidresist degradation

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent applies parameter changes by selecting optimal multiplicity values from stored relation data that satisfy temperature constraints. The system dynamically adjusts multiplicity based on writing conditions, pattern density, and stage speed to maximize throughput without exceeding temperature thresholds that cause resist degradation

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent implements feedback by using pre-calculated relation data that accounts for the cumulative temperature effect of multiple writing passes. The system selects multiplicity and stage speed combinations that maintain temperature within safe ranges, effectively using stored thermal response data as feedback to prevent resist degradation

Inventive Principle:

Principle #23Feedback

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 enables writing operations to be performed within an acceptable temperature range, ensuring correctable CD accuracy and resist integrity without excessive time consumption, thus balancing throughput and quality.

Implementation Method 1

a significant resist heating occurs depending on writing conditions

Methodology Applied

Scientific EffectJoule heating: Joule Heating

Implementation Method 2

the temperature increase of the resist is within an allowable temperature increase

Methodology Applied

Scientific EffectAbsorption (EM radiation): Absorption (EM radiation)

Data Source

PatentUS20250336644A1Stage speed obtaining method, multiple charged particle beam writing method, and method for obtaining combination of stage speed and multiplicity in multiple charged particle beam writing

Publication Date: 2025.10.30 NUFLARE TECH INC

AI summary

A stage speed obtaining method for performing writing on a substrate with a charged particle beam while moving a stage on which the substrate coated with resist is placed includes storing, in a storage device, relation data among a stage speed of the stage, a dose for one writing processing, and a temperature increase of the resist, reading the relation data from the storage device by a processing circuit, obtaining, using the relation data, a stage speed at which the temperature increase of the resist is equal to or less than a preset allowable temperature increase, and outputting an obtained stage speed.