Oversized Mesa Replica Template for Nanoimprint Extrusion Control

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Solution Overview

Problem

In nanoimprint lithography, the limited lifetime of templates due to direct contact with formable materials leads to extrusion of resist material beyond patterning surfaces, causing defects and requiring frequent cleaning, which can alter critical feature dimensions and reduce template usability.

Innovation Solution

The use of oversized mesas on first generation replica templates ensures that extruded polymerizable material adheres to the substrate sidewalls rather than the template sidewalls, preventing defects and allowing for one-time wet etch removal, thus maintaining feature accuracy and extending template lifespan.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If template直接接触 formable material for pattern transfer, then pattern transfer efficiency is improved, but template lifetime deteriorates due to extrusion of material beyond patterning surfaces

Engineering Contradiction:

Improvepattern transfer efficiencyVSAvoidtemplate lifetime

Core Design Contradiction:

ProductivityVSDuration of action of stationary object

Solution Approach 1:

An oversized mesa structure is introduced as an intermediary between the template patterning surface and the substrate. This mesa acts as a sacrificial intermediary that captures extruded material through its larger perimeter, preventing direct contact between extruded material and the critical template edges, thereby extending template lifetime while maintaining pattern transfer efficiency

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The oversized mesa is designed as a disposable sacrificial structure that intentionally allows extrusion onto its sidewalls. This sacrificial mesa can be easily removed via wet etch, protecting the main template from degradation and enabling template reuse without frequent cleaning that would alter critical feature dimensions

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

2Object-generated harmful factors

If template is cleaned frequently to remove extruded material, then template surface cleanliness is improved, but manufacturing precision deteriorates due to alteration of critical feature dimensions

Engineering Contradiction:

Improvetemplate surface cleanlinessVSAvoidcritical feature dimensions

Core Design Contradiction:

Object-generated harmful factorsVSManufacturing precision

Solution Approach 1:

The harmful extruded material is extracted and isolated onto the oversized mesa sidewalls rather than the main template surface. By spatially separating the extrusion location from the critical patterning regions, the need for frequent cleaning of the main template is eliminated, preserving critical feature dimensions while managing material extrusion

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The oversized mesa serves as a sacrificial structure that accumulates extruded material on its sidewalls. This disposable mesa can be removed in one wet etch step, eliminating the need for repeated cleaning operations that would otherwise alter the critical dimensions of the main template

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Duration of action of stationary object

If mesa area on template is increased to prevent extrusion adherence, then template usability is improved, but device area is worsened due to larger perimeter occupying active region

Engineering Contradiction:

Improvetemplate usabilityVSAvoiddevice area

Core Design Contradiction:

Duration of action of stationary objectVSArea of stationary object

Solution Approach 1:

The template structure is segmented into two functional zones: a smaller active patterning region for device fabrication and a larger oversized mesa region for capturing extruded material. This segmentation allows the mesa to extend beyond the active region perimeter, providing extrusion capture capability while minimizing interference with the active device area through proper spatial arrangement

Inventive Principle:

Principle #1Segmentation

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 prevents extruded resist from causing defects in subsequent replication processes and reduces the need for repeated cleaning, maintaining the integrity of critical features and extending the usable life of replica templates.

Implementation Method 1

filling a volume defined between the patterning region of the template and the active region of the substrate with a polymerizable material; solidifying the polymerizable material to form a patterned layer on the substrate

Methodology Applied

Scientific EffectPhotopolymerization: Photopolymerisation

Data Source

PatentUS10288999B2Methods for controlling extrusions during imprint template replication processes

Publication Date: 2019.05.14 CANON KK

AI summary

A method that can be used in the formation of replica imprint templates. The method can include providing a substrate with a substrate mesa defining an active region having a first area and a template with a template mesa defining a patterning region having a second area, where first area is larger than the second area. The template can then be positioned relative to the substrate such that patterning region of the template mesa overlaps the active region of the substrate mesa. The method can be used in forming a replica template. The formed replica template can be used to form a patterned layer on e.g. a semiconductor wafer in fabricating an electronic device. A system can be configured to carry out the methods.