Photosensitive Substrate Heating for Line Edge Roughness Control

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Solution Overview

Problem

In semiconductor exposure apparatuses, the wide spectral linewidths of KrF and ArF excimer laser beams lead to chromatic aberration, reducing resolution and necessitating the use of line narrowing modules to narrow the spectral linewidth.

Innovation Solution

A photosensitive substrate developing method that involves heating the substrate with a pulse laser beam having multiple center wavelengths to create a temperature distribution with a gradient, followed by developer supply for development.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a pulse laser beam with multiple center wavelengths is used for exposure, then productivity is improved through faster exposure speed, but manufacturing precision deteriorates due to off-axis chromatic aberration and line edge roughness

Engineering Contradiction:

Improveexposure speedVSAvoidline edge roughness

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies local quality by creating a non-uniform temperature distribution across the photosensitive substrate during post-exposure heating. Specifically, the center region of the substrate is heated to a higher temperature than the peripheral regions, establishing a temperature gradient that locally optimizes the chemical reactions in different zones. This localized temperature control compensates for the wavelength-induced variations in exposure characteristics, thereby reducing line edge roughness while maintaining the productivity benefits of multi-wavelength pulsed laser exposure.

Inventive Principle:

Principle #3Local quality

2Manufacturing precision

If a line narrowing module is added to narrow the spectral linewidth, then manufacturing precision is improved by reducing chromatic aberration, but device complexity increases

Engineering Contradiction:

ImproveresolutionVSAvoidlaser apparatus structure

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent employs parameter changes by utilizing a pulse laser beam with multiple center wavelengths instead of narrowing the spectral linewidth to a single wavelength. This approach changes the wavelength parameter from a narrow single value to a broader multi-peaked distribution, thereby eliminating the need for line narrowing modules and their associated chromatic aberration correction mechanisms. The multiple wavelengths are strategically selected and controlled to achieve both high resolution and reduced device complexity.

Inventive Principle:

Principle #35Parameter changes

3Manufacturing precision

If uniform temperature heating is applied after exposure, then manufacturing precision is improved through consistent development, but line edge roughness increases due to lack of compensation for wavelength variations

Engineering Contradiction:

Improvepattern uniformityVSAvoidline edge roughness

Core Design Contradiction:

Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The patent applies asymmetry by deliberately creating an asymmetric temperature distribution across the photosensitive substrate during post-exposure heating. The temperature profile is designed to be non-uniform, with the center region receiving higher temperatures and the peripheral regions receiving lower temperatures. This asymmetric heating pattern compensates for the asymmetric effects of off-axis chromatic aberration and multi-wavelength exposure variations, thereby reducing line edge roughness and improving overall pattern quality.

Inventive Principle:

Principle #4Asymmetry

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 method effectively adjusts line edge roughness and improves pattern quality on the photosensitive substrate, even when off-axis chromatic aberration occurs during exposure with multiple wavelengths.

Implementation Method 1

heating a photosensitive substrate exposed by scanning each of a plurality of scan fields included in the photosensitive substrate in a first direction with a pulse laser beam

Methodology Applied

Scientific EffectLaser heating: Laser

Implementation Method 2

have a temperature distribution having a temperature gradient in a second direction intersecting the first direction on a surface of the photosensitive substrate

Methodology Applied

Scientific EffectTemperature gradient: Temperature Gradient

Implementation Method 3

exposed by scanning each of a plurality of scan fields included in the photosensitive substrate in a first direction with a pulse laser beam via a photomask

Methodology Applied

Scientific EffectPhotomask filtering: Filter (optical)

Data Source

PatentUS20250060683A1Photosensitive substrate developing method, photomask creating method, and electronic device manufacturing method

Publication Date: 2025.02.20 GIGAPHOTON INC

AI summary

A photosensitive substrate developing method includes heating a photosensitive substrate exposed by scanning each of a plurality of scan fields included in the photosensitive substrate in a first direction with a pulse laser beam including a plurality of center wavelengths via a photomask so as to have a temperature distribution having a temperature gradient in a second direction intersecting the first direction on a surface of the photosensitive substrate in each of the scan fields, and supplying a developer to the surface of the photosensitive substrate to perform development after heating the photosensitive substrate.