Electrostatic Chuck Particle Cleaning With Optical Detection

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Solution Overview

Problem

Contamination on the electrostatic chuck in EUV semiconductor lithography processes can lead to photomask deformation and pattern transfer issues, affecting the performance of the wafer.

Innovation Solution

An electrostatic chuck cleaning tool and method that utilize a platform with a spindle and motor for precise movement and rotation, combined with a vacuum source and optical inspection instrument, to detect and remove particles from the electrostatic chuck without direct contact.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a cleaning tool contacts the electrostatic chuck to remove particles, then cleaning effectiveness is improved, but the risk of damaging the chuck or introducing new contamination increases

Engineering Contradiction:

Improvecleaning effectivenessVSAvoiddamage or contamination risk

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a platform as an intermediary between the cleaning tool and the electrostatic chuck. The platform makes contact with the chuck surface during cleaning operations, allowing particle removal while the platform itself serves as a replaceable sacrificial element that protects the valuable electrostatic chuck from direct contact and potential damage

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The platform is designed as a disposable or easily replaceable component. Rather than risking damage to the expensive electrostatic chuck, the system uses a lower-cost platform that can be replaced if contaminated or damaged during the cleaning process, effectively transferring the risk from the critical component to a sacrificial one

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

2Productivity

If direct contact cleaning is used on the electrostatic chuck, then particle removal capability is improved, but the precision and control of the cleaning process deteriorates

Engineering Contradiction:

Improveparticle removal capabilityVSAvoidcleaning process control

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent replaces direct mechanical contact between the cleaning tool and the electrostatic chuck with a two-stage system: first, an optical inspection instrument detects particle locations with high precision using non-contact optical methods; second, a platform positioned at the detected locations performs localized cleaning. This substitution of direct mechanical cleaning with optically-guided selective cleaning maintains both effectiveness and precision

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system incorporates optical inspection that detects particle locations on the electrostatic chuck, providing feedback information that guides the positioning and operation of the cleaning platform. This closed-loop feedback ensures that cleaning is applied only where needed and with precise control over the cleaning process parameters

Inventive Principle:

Principle #23Feedback

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 solution effectively detects and removes particles from the electrostatic chuck, preventing photomask deformation and improving the fidelity of pattern transfer onto the wafer, thereby enhancing the overall performance and reducing contamination-related issues.

Implementation Method 1

transmitting a radiation toward an electrostatic chuck, receiving a reflection of the radiation, analyzing the reflection of the radiation

Methodology Applied

Scientific EffectReflection: Reflection

Implementation Method 2

drawing the particle into the vacuum source through the exhaust duct after releasing the particle from the electrostatic chuck

Methodology Applied

Scientific EffectSuction: Suction

Implementation Method 3

an electrostatic chuck (also known as an R-chuck, an E-chuck, or an ESC) is configured to hold a reflection-type mask through electrostatic forces

Methodology Applied

Scientific EffectElectrostatic forces: Electrostatics

Data Source

PatentUS12347716B2Method for cleaning electrostatic chuck

Publication Date: 2025.07.01 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

A method includes emitting, by a first portion of an optical inspection instrument, a radiation toward a supporting surface of a chuck, wherein the chuck is configured for fixing a semiconductor workpiece on the supporting surface, and the optical inspection instrument faces the supporting surface; receiving, by a second portion of the optical inspection instrument, a reflection of the radiation reflected from the chuck; analyzing the reflection of the radiation; determining whether a particle is present on the supporting surface of the chuck based on the analyzing the reflection of the radiation; and removing the particle by using a cleaning tool comprising an exhaust duct.