Lithography Post-Treatment Coating for Resist Resolution

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Solution Overview

Problem

As semiconductor devices miniaturize, lithography processes become increasingly challenging due to difficulties in achieving high resolution and uniformity, leading to inefficiencies in pattern formation and energy consumption.

Innovation Solution

The implementation of a post-treatment coating material containing photo-acid generators (PAG) and thermal acid generators (TAG) that react with unexposed resist layer portions to improve pattern resolution and reduce energy requirements, by forming acids and controlling diffusion to refine feature sizes and aspect ratios during the lithography process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional lithography processes are used for miniaturized devices, then device integration is achieved, but resolution and uniformity deteriorate

Engineering Contradiction:

Improvelithography resolutionVSAvoiddevice miniaturization capability

Core Design Contradiction:

Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The patent applies preliminary action by forming a post-treatment coating material containing photo-acid generators (PAG) and thermal acid generators (TAG) on the resist layer before the main lithography exposure. This pre-applied coating material prepares the resist layer for subsequent acid diffusion that will refine the pattern during development, thereby improving resolution for miniaturized devices without requiring changes to the core lithography process parameters.

Inventive Principle:

Principle #10Preliminary action

2Manufacturing precision

If higher resolution is achieved through conventional means, then pattern detail improves, but energy consumption increases

Engineering Contradiction:

Improvepattern resolutionVSAvoidlithography energy consumption

Core Design Contradiction:

Manufacturing precisionVSUse of energy by moving object

Solution Approach 1:

The patent changes the chemical parameters of the resist system by incorporating post-treatment coating material containing PAG and TAG compounds. This chemical modification enables the resist to undergo acid diffusion and reaction processes that enhance pattern resolution without requiring increased exposure energy, thereby achieving higher resolution while maintaining or reducing energy consumption compared to conventional high-resolution lithography methods.

Inventive Principle:

Principle #35Parameter changes

3Area of moving object

If feature dimensions are reduced for higher integration, then device density increases, but resist layer stability deteriorates

Engineering Contradiction:

Improvefeature sizeVSAvoidresist layer integrity

Core Design Contradiction:

Area of moving objectVSStability of the object's composition

Solution Approach 1:

The patent introduces an intermediary substance - the post-treatment coating material containing PAG and TAG - that mediates between the exposure process and the resist layer. This intermediary releases acids that diffuse into the resist to modify its solubility characteristics, enabling precise pattern formation at reduced feature sizes while maintaining resist layer stability and preventing bending or cracking during processing.

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 enhances the resolution and uniformity of the lithography process, reduces the energy needed for pattern formation, and minimizes the risk of resist layer bending or cracking by refining the dimensions and aspect ratios of unexposed features.

Implementation Method 1

a post treatment coating material (120) is formed to cover the unexposed portions (116) of the resist layer (106) and a post treatment process (122) is performed on the post treatment coating material (120) so that a peripheral portion (124) of the unexposed portions (116) of the resist layer (106) reacts with the post treatment coating material (120)

Methodology Applied

Scientific EffectPhoto-acid generation: Photodissociation

Implementation Method 2

a post treatment coating material containing photo-acid generators (PAG) and thermal acid generators (TAG) that react with unexposed resist layer portions

Methodology Applied

Scientific EffectThermal acid generation: Thermolysis

Implementation Method 3

forming acids and controlling diffusion to refine feature sizes and aspect ratios

Methodology Applied

Scientific EffectAcid diffusion: Diffusion

Data Source

PatentUS11281107B2Method for performing lithography process with post treatment

Publication Date: 2022.03.22 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

Methods for performing a lithography process are provided. The method for performing a lithography process includes forming a resist layer over a substrate and exposing a portion of the resist layer to form an exposed portion between unexposed portions. The method for performing a lithography process further includes developing the resist layer to remove the exposed portion of the resist layer such that an opening is formed between the unexposed portions and forming a post treatment coating material in the opening and over the unexposed portions of the resist layer. The method for performing a lithography process further includes reacting a portion of the unexposed portions of the resist layer with the post treatment coating material by performing a post treatment process and removing the post treatment coating material.