Recessed High-Contrast Alignment Marks via Two-Stage Imprinting

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing nano-fabrication techniques face challenges in protecting fine patterned features during the deposition and removal of high contrast materials, which can lead to defects and require extensive processing steps, including the use of trenches that occupy valuable space and may cause uniformity issues in semiconductor processing.

Innovation Solution

A two-stage imprinting technique is employed, involving a feature-blocking step with a formable layer and a secondary planarizing step using high contrast materials, where a first layer protects fine features and a second layer is planarized to ensure precise removal of high contrast materials, minimizing direct contact and ambient particle exposure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If high contrast material is deposited over the alignment area to create high contrast alignment marks, then the alignment mark contrast is improved, but the fine feature area may come into direct contact with the high contrast material causing defects

Engineering Contradiction:

Improvealignment mark contrastVSAvoidfine feature integrity

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The template surface is divided into distinct alignment area and fine feature area zones. The alignment area is specifically prepared to receive high contrast material deposition while the fine feature area is protected through selective masking, allowing contrast enhancement without contaminating sensitive regions.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A masking layer is introduced as an intermediary between the high contrast material and the fine feature area. This masking layer prevents direct contact between the deposited material and fine features, eliminating the harmful interaction while allowing the alignment marks to be formed in the alignment area.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of manufacture

If traditional methods are used to deposit and remove high contrast materials, then alignment marks can be formed, but extensive processing steps are required including trenches that occupy valuable space and cause uniformity issues

Engineering Contradiction:

Improvealignment mark formationVSAvoidprocessing steps

Core Design Contradiction:

Ease of manufactureVSDevice complexity

Solution Approach 1:

The problematic trench structure is completely removed from the process. Instead of using trenches to define alignment mark regions, the invention directly deposits high contrast material in the alignment area using a masking approach, eliminating the extra structural elements and associated processing complexity.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The masking layer is applied in advance before high contrast material deposition. This preliminary masking action defines the deposition regions and protects fine features beforehand, streamlining the overall process by preventing the need for subsequent complex removal and cleaning steps.

Inventive Principle:

Principle #10Preliminary action

3Manufacturing precision

If high contrast materials are deposited without protection, then alignment marks are formed, but ambient particle exposure and direct contact with fine features cause defects

Engineering Contradiction:

Improvealignment mark formationVSAvoidambient particle exposure

Core Design Contradiction:

Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The masking layer serves as a protective intermediary that shields fine features from ambient particles and deposited material during the high contrast material deposition process. This intermediary barrier prevents harmful exposures while allowing the alignment marks to be formed in the exposed alignment area.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 effectively prevents high contrast materials from contacting fine features, reduces processing steps, and maintains feature uniformity, thereby enhancing the precision and yield of nano-fabrication processes, especially in creating recessed high-contrast alignment marks.

Implementation Method 1

a formable layer is formed over the fine feature area while leaving the alignment area exposed. A high contrast material, which can be a metal, is then deposited over both the alignment area and the first layer

Methodology Applied

Scientific EffectPhysical Vapour Deposition: Physical Vapour Deposition

Implementation Method 2

A high contrast material, which can be a metal, is then deposited over both the alignment area and the first layer

Methodology Applied

Scientific EffectPhysical Vapour Deposition: Physical Vapour Deposition

Implementation Method 3

A second layer is then formed over the deposited high contrast material. A portion of the second layer is then subsequently removed such that a remaining portion of the second layer remains in recessions of the alignment area

Methodology Applied

Scientific EffectPlanarization:

Data Source

PatentUS8935981B2High contrast alignment marks through multiple stage imprinting

Publication Date: 2015.01.20 MII NEWCO

AI summary

Two-stage imprinting techniques capable of protecting fine patterned features of an imprint lithography template are herein described. In particular, such techniques may be used during fabrication of recessed high-contrast alignment marks for preventing deposited metal layers from coming into contact with fine features etched into the template.