Resist-Modifying Composition for Double Patterning Lithography

Solution Overview

Problem

Current double patterning processes in lithography require multiple etchings, leading to reduced throughput, pattern deformation, and misregistration issues due to the limitations of existing resist materials and processes, particularly in achieving the 32-nm node resolution with high overlay accuracy.

Innovation Solution

A pattern forming process using a resist-modifying composition comprising a copolymer with lactone and acid labile groups, combined with a nitrogen-containing compound and solvent, to inactivate the first resist pattern, allowing a second resist pattern to be formed with reduced distance between lines while preventing pattern collapse and minimizing development defects, all achieved through a single dry etching step.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If multiple etchings are performed in double patterning process, then pattern formation is achieved, but throughput is reduced and pattern deformation occurs

Engineering Contradiction:

Improvepattern formation accuracyVSAvoidthroughput

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

The first resist pattern is inactivated in advance by treating with the resist-modifying composition before the second exposure, so that it serves as a stable mask during subsequent processing without requiring multiple etchings. This preliminary inactivation allows the first pattern to maintain its structural integrity while enabling efficient single-etch double patterning.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The chemical properties of the first resist pattern are changed by introducing the resist-modifying composition containing fluorinated base resin and nitrogen-containing compound, which inactivates the resist and prevents unwanted reactions during the second exposure and development, thereby enabling accurate pattern formation with reduced processing steps.

Inventive Principle:

Principle #35Parameter changes

2Manufacturing precision

If multiple etchings are performed in double patterning process, then pattern formation is achieved, but pattern misregistration occurs

Engineering Contradiction:

Improveoverlay accuracyVSAvoidthroughput

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

The first resist pattern is inactivated in advance by treating with the resist-modifying composition before the second exposure, so that it serves as a stable mask during subsequent processing without requiring multiple etchings. This preliminary inactivation allows the first pattern to maintain its structural integrity while enabling efficient single-etch double patterning.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The first resist pattern is designed to be inactivated and discarded after serving its masking function, replaced by the second resist pattern. This approach eliminates the need for multiple etchings and associated alignment issues, achieving high overlay accuracy through a simplified single-etch process.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Productivity

If resist pattern is inactivated using conventional methods, then second resist process can proceed, but pattern collapse occurs and development defects increase

Engineering Contradiction:

Improveprocess efficiencyVSAvoidpattern integrity

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The chemical properties of the first resist pattern are changed by introducing the resist-modifying composition containing fluorinated base resin and nitrogen-containing compound, which inactivates the resist and prevents unwanted reactions during the second exposure and development, thereby enabling accurate pattern formation with reduced processing steps.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The resist-modifying composition combines fluorinated base resin for inactivation with nitrogen-containing compound to prevent pattern collapse. This composite formulation provides both the necessary chemical modification to inactivate the first resist and the structural support to maintain pattern integrity during subsequent processing, eliminating development defects.

Inventive Principle:

Principle #40Composite materials

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

The process enables efficient double patterning with improved throughput and reduced pattern deformation, achieving finer line widths and higher overlay accuracy by modifying the contact angle of the resist pattern to optimize water interaction and resist solubility.

Implementation Method 1

modifying the contact angle of the resist pattern to optimize water interaction and resist solubility

Methodology Applied

Scientific EffectContact angle modification: Wetting

Data Source

PatentUS8367310B2Pattern forming process and resist-modifying composition

Publication Date: 2013.02.05 SHIN ETSU CHEMICAL CO LTD

AI summary

A patterning process includes (1) coating and baking a first positive resist composition to form a first resist film, exposing, post-exposure baking, and alkali developing to form a first resist pattern, (2) applying a resist-modifying composition to the first resist pattern and heating to modify the first resist pattern, (3) coating and baking a second positive resist composition to form a second resist film, exposing, post-exposure baking, and alkali developing to form a second resist pattern. The modified first resist film has a contact angle with pure water of 50°-85°.