Imprint Lithography Curing with Dual Light Sources for Resist Defect Control

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Solution Overview

Problem

Current imprint methods face challenges in achieving efficient pattern transfer and curing of resist materials on semiconductor wafers, leading to issues such as resist seepage and protrusions, which affect subsequent etching processes and reduce throughput.

Innovation Solution

The use of a dual-light source system with an illuminance changing portion that selectively controls light distribution, allowing for simultaneous filling and curing of resist in recessed areas while preventing curing in central portions, thereby reducing seepage and protrusions, and improving processing time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a single light source is used to cure the resist, then the curing process is simple, but resist seepage and protrusions occur affecting subsequent etching processes

Engineering Contradiction:

Improvecuring process simplicityVSAvoidresist pattern quality

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The single light source is divided into two separate light sources: a first light source for initial curing and a second light source for final curing. This segmentation allows different curing stages to be performed with different light sources, preventing resist seepage and protrusions while maintaining manufacturing feasibility

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The first light source performs preliminary curing of the resist before the template is fully pressed. This preliminary action stabilizes the resist in recessed portions, preventing seepage during the pressing process, while the second light source completes the curing afterward

Inventive Principle:

Principle #10Preliminary action

2Manufacturing precision

If the template is pressed against the resist to fill recessed portions, then pattern transfer is achieved, but resist seepage and protrusions occur

Engineering Contradiction:

Improvepattern transfer qualityVSAvoidresist seepage and protrusions

Core Design Contradiction:

Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The first light source cures the resist in recessed portions before the template pressing is complete. This preliminary curing action prevents the resist from seeping out during pressing, while still allowing complete pattern transfer to occur

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The curing process is made continuous through two stages: initial curing with the first light source during pressing, and final curing with the second light source after pressing. This continuous action ensures pattern transfer quality while preventing resist defects

Inventive Principle:

Principle #20Continuity of useful action

3Ease of manufacture

If the resist is cured uniformly across the entire pattern, then the curing process is straightforward, but processing time increases reducing throughput

Engineering Contradiction:

Improvecuring process simplicityVSAvoidprocessing throughput

Core Design Contradiction:

Ease of manufactureVSProductivity

Solution Approach 1:

The uniform curing process is segmented into two separate curing operations with two different light sources. The first light source quickly cures critical areas during pressing, and the second light source completes curing afterward, reducing total processing time while maintaining simplicity

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The curing is performed in periodic stages: initial curing with the first light source during the pressing cycle, followed by final curing with the second light source after pressing. This periodic action reduces overall processing time compared to single-stage uniform curing

Inventive Principle:

Principle #19Periodic 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 enhances the throughput by allowing for controlled curing and filling of resist patterns, reducing the occurrence of resist seepage and protrusions, and ensuring uniform hardness across the resist pattern, thus improving the quality of semiconductor device manufacturing.

Implementation Method 1

a first light source that irradiates light onto a substrate, a second light source that irradiates light onto the substrate

Methodology Applied

Scientific EffectPhotopolymerisation: Photopolymerisation

Implementation Method 2

an illuminance changing portion that selectively controls a light distribution from the first light source

Methodology Applied

Scientific EffectLight absorption and distribution control: Absorption (EM radiation)

Data Source

PatentUS11837469B2Imprint apparatus, imprint method, and method of manufacturing semiconductor device

Publication Date: 2023.12.05 KIOXIA CORP

AI summary

According to one embodiment, an imprint apparatus includes a first light source positioned to irradiate a substrate with light, a second light source positioned to irradiate the substrate with light, an illuminance changing portion selectively configured to change the illuminance distribution of light from the first light source on an irradiation surface on the substrate, and a controller configured to control the first light source, the second light source and the illuminance changing portion to irradiate the substrate with light from the first light source, and to subsequently irradiate the substrate with light from the second light source directly through the template.