Dynamic Developer Concentration for Lithography Uniformity

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The semiconductor industry faces challenges in achieving uniform critical dimensions and reducing line edge roughness and line width roughness in resist patterns during the lithography process, leading to manufacturing defects, especially in nanometer-scale fabrication.

Innovation Solution

A flexible solution adjustment method is introduced, where the chemical concentration of the developer is dynamically adjusted over time during the developing process, allowing for more even development across the wafer and improving critical dimension uniformity by varying the concentration of developing chemicals and surfactants in multiple stages.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a fixed concentration developer is used during the developing process, then the process is simple and fast, but critical dimension uniformity deteriorates and line edge roughness increases

Engineering Contradiction:

Improvecritical dimension uniformityVSAvoiddeveloper concentration control

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies dynamics by transitioning from a static fixed-concentration developer system to a dynamic multi-stage developer system where the concentration is adjusted at different time points during the developing process. The developer concentration is set to a first concentration for an initial time period, then adjusted to a second concentration for a subsequent time period, allowing the system to adapt to changing development needs and achieve uniform critical dimensions across the wafer.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent implements parameter changes by systematically varying the developer concentration parameter throughout the developing process. By changing the concentration from a first value to a second value at different stages, the process optimizes both the removal of exposed resist and the maintenance of pattern fidelity, thereby improving critical dimension uniformity while controlling line edge roughness.

Inventive Principle:

Principle #35Parameter changes

2Productivity

If the developing process is accelerated to increase productivity, then manufacturing efficiency improves, but line width roughness and critical dimension variance worsen

Engineering Contradiction:

Improvemanufacturing efficiencyVSAvoidline width roughness

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies segmentation by dividing the developing process into multiple distinct stages, each with its own optimized developer concentration. This segmentation allows the process to simultaneously achieve high productivity through optimized total development time and high precision through stage-specific concentration control, preventing line width roughness while maintaining manufacturing efficiency.

Inventive Principle:

Principle #1Segmentation

3Speed

If the developer concentration is increased to improve development speed, then productivity increases, but over-development at the wafer center occurs and critical dimension uniformity deteriorates

Engineering Contradiction:

Improvedevelopment speedVSAvoidcritical dimension uniformity

Core Design Contradiction:

SpeedVSManufacturing precision

Solution Approach 1:

The patent implements periodic action by applying different developer concentrations at different time periods during the developing process. A higher concentration may be applied initially for rapid development, followed by a lower concentration to prevent over-development, thereby maintaining both speed and critical dimension uniformity across the wafer surface.

Inventive Principle:

Principle #19Periodic action

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 critical dimension uniformity, reduces line edge roughness and line width roughness, and prevents over-development at the wafer center, resulting in improved quality of resist patterns and subsequent semiconductor devices.

Implementation Method 1

a concentration of the developing chemical in the developer is a function of time during the applying of the developer

Methodology Applied

Scientific EffectDiffusion: Diffusion

Implementation Method 2

applying a developer to the exposed first layer, resulting in a pattern over the substrate

Methodology Applied

Scientific EffectChemical reaction: Chemical Bonding

Implementation Method 3

improving critical dimension uniformity by varying the concentration of developing chemicals and surfactants

Methodology Applied

Scientific EffectSurfactant: Surfactant

Data Source

PatentUS11531271B2Lithography patterning with flexible solution adjustment

Publication Date: 2022.12.20 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

A method for lithography patterning includes forming a first layer over a substrate, the first layer being radiation-sensitive, exposing the first layer to a radiation, mixing a first solution and a second solution, thereby forming a developer, and dispensing the developer to the exposed first layer to form a pattern over the substrate. The dispensing of the developer includes varying a concentration of a developing chemical in the developer in multiple stages, such that the concentration of the developing chemical in the developer increases from a first stage to a subsequent second stage, and increases from the second stage to a subsequent third stage real-time during the dispensing.