Resist Dispensing Nozzle Solvent Retraction Against Residue Crystallization

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Solution Overview

Problem

The crystallization of resist material residues in the dispensing nozzle during idle periods leads to defects in the deposited resist layer on the wafer, causing non-uniformity in critical dimension (CD) and affecting the integrity of the lithographic process.

Innovation Solution

A solvent cleaning mechanism is employed to clean the nozzle tip and fill the tube with a second solvent having a higher vapor pressure than the resist material solvent, creating an empty volume that prevents resist material residues from hardening and crystallizing, thereby reducing defects in the resist layer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the dispensing nozzle is left idle without cleaning, then the system maintains simplicity and reduces cleaning operations, but resist material residues crystallize and harden in the nozzle, causing defects in the deposited resist layer

Engineering Contradiction:

Improveresist layer qualityVSAvoidcleaning mechanism complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The system performs preliminary cleaning action by introducing a second solvent into the dispensing nozzle before resist material residues can crystallize and harden. This preventive cleaning maintains nozzle integrity and prevents defects in the deposited resist layer, resolving the contradiction between maintaining simple operations and ensuring reliable resist quality.

Inventive Principle:

Principle #10Preliminary action

2Manufacturing precision

If a solvent cleaning mechanism is introduced to prevent crystallization, then resist material remains in liquid state and defects are reduced, but the system complexity increases

Engineering Contradiction:

Improvecritical dimension uniformityVSAvoidsolvent cleaning system

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

A second solvent is introduced as an intermediary substance to prevent resist material crystallization in the dispensing nozzle. This intermediary solvent maintains the resist material in liquid state, ensuring uniform critical dimensions in the deposited resist layer while managing the added system complexity through integrated solvent delivery.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If the nozzle is cleaned frequently to prevent defects, then resist layer quality improves, but productivity decreases due to additional cleaning steps

Engineering Contradiction:

Improveresist layer integrityVSAvoidwafer processing throughput

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The dispensing nozzle performs self-service cleaning by automatically introducing a second solvent to dissolve and remove resist material residues during or between dispensing operations. This self-cleaning mechanism maintains resist layer integrity and prevents defects without requiring separate manual cleaning steps, thereby preserving wafer processing throughput.

Inventive Principle:

Principle #25Self-service

4Reliability

If resist material is kept flowing continuously to prevent crystallization, then nozzle reliability improves, but resist material waste increases

Engineering Contradiction:

Improvenozzle dispensing reliabilityVSAvoidresist material waste

Core Design Contradiction:

ReliabilityVSLoss of substance

Solution Approach 1:

A second solvent acts as an intermediary to prevent resist material crystallization in the nozzle during idle periods without requiring continuous resist material flow. The solvent maintains a protective environment that prevents residue hardening, ensuring nozzle dispensing reliability while eliminating the need for continuous resist flow and reducing resist material waste.

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

The solvent cleaning process effectively maintains the resist material in a liquid state, minimizing defects and ensuring uniformity of the resist layer, thereby enhancing the precision and yield of the lithographic process.

Implementation Method 1

a first solvent having a lower vapor pressure than the resist material solvent

Methodology Applied

Scientific EffectVapor pressure: Vapour Pressure

Implementation Method 2

The gap includes vapor of the first solvent. The vapor of the first solvent in the gap prevents the resist material residues from drying

Methodology Applied

Scientific EffectEvaporation: Evaporation

Implementation Method 3

fill the tube with a second solvent having a higher vapor pressure than the resist material solvent

Methodology Applied

Scientific EffectVapor pressure: Vapour Pressure

Data Source

PatentUS12541149B2Resist dispensing system and method of use

Publication Date: 2026.02.03 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

In a method, a resist material is dispensed through a tube of a nozzle of a resist pump system on a wafer. The tube extends from a top to a bottom of the nozzle and has upper, lower, and middle segments. When not dispensing, the resist material is retracted from the lower and the middle segments, and maintained in the upper segment of the tube. When retracting, a first solvent is flown through a tip of the nozzle at the bottom of the nozzle to fill the lower segment of the tube with the first solvent and to produce a gap in the middle segment of the tube between the resist material and the first solvent. The middle segment includes resist material residues on an inner surface wall of the tube and vapor of the first solvent. The vapor of the first solvent prevents the resist material residues from drying.