Electrostatic Chuck Pin Hole Sealing Against RF Plasma Discharge

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The increasing demand for higher RF power in semiconductor manufacturing leads to electrical discharge phenomena in the cooling gas supplying holes and pin holes of electrostatic chucks, causing damage to the substrate supporting device and the substrate.

Innovation Solution

An electrostatic chuck with a pin hole that includes a piezoelectric expansion member, which reduces the diameter of the pin hole when activated, preventing the introduction of cooling gas and plasma, thereby minimizing electrical discharges.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a pin hole with a relatively large diameter is used to accommodate the lift pin, then the lift pin can move smoothly, but cooling gas and plasma are easily introduced into the pin hole causing electrical discharge

Engineering Contradiction:

Improvelift pin movementVSAvoidelectrical discharge

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The pin hole diameter is made dynamically adjustable through the expansion member (e.g., balloon or bellows structure). During substrate processing, the expansion member expands to reduce the pin hole diameter, preventing gas and plasma entry. During lift pin movement, the expansion member contracts to enlarge the pin hole diameter, facilitating smooth pin movement. This dynamic adjustment resolves the contradiction between maintaining lift pin mobility and preventing electrical discharge.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The physical parameter of the pin hole diameter is changed based on operational requirements. The expansion member alters the dimensional parameter of the pin hole from a fixed large diameter to a variable diameter that can be reduced during plasma processing to prevent electrical discharge, while maintaining adequate size during lift pin operation.

Inventive Principle:

Principle #35Parameter changes

2Object-affected harmful factors

If the pin hole diameter is reduced to prevent electrical discharge, then cooling gas and plasma are prevented from entering, but the lift pin cannot move smoothly

Engineering Contradiction:

Improveelectrical discharge preventionVSAvoidlift pin movement

Core Design Contradiction:

Object-affected harmful factorsVSEase of operation

Solution Approach 1:

The expansion member provides dynamic dimensional adjustment of the pin hole. When contraction is needed for lift pin movement, the expansion member contracts to provide sufficient clearance. When protection is needed during plasma processing, the expansion member expands to seal the pin hole. This temporal separation of functions resolves the contradiction.

Inventive Principle:

Principle #15Dynamics

3Productivity

If higher RF power is used for plasma generation, then plasma processing efficiency is improved, but electrical discharge in cooling gas supplying holes and pin holes increases

Engineering Contradiction:

Improveplasma processing efficiencyVSAvoidelectrical discharge

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The expansion member proactively seals the pin hole and cooling gas supplying holes before electrical discharge can occur during high RF power plasma processing. This preliminary protective action prevents the harmful effect of electrical discharge that would otherwise be intensified by higher RF power, allowing efficient plasma processing without the associated discharge damage.

Inventive Principle:

Principle #9Preliminary anti-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

The use of a piezoelectric expansion member in the electrostatic chuck effectively reduces the occurrence of electrical discharges in the substrate processing apparatus, protecting the substrate and the chuck from damage.

Implementation Method 1

an expansion member which is provided at an inner circumference of the one of the at least one pin hole, the expansion member having an inner circumferential surface that, in response to a first power, selectively holds or releases an outer circumferential surface of the lift pin

Methodology Applied

Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentUS12243727B2Substrate processing apparatus including electrostatic chuck, substrate processing method, and method of manufacturing electrostatic chuck

Publication Date: 2025.03.04 SYSTEM ENGINEERING MEGA SOLUTION CO LTD

AI summary

An electrostatic chuck includes a chuck body which supports a substrate, at least one pin hole penetrating the chuck body in a vertical direction, a lift pin disposed in one of the at least one pin hole, wherein the lift pin moves along the one of the at least one pin hole, and an expansion member which is provided at an inner circumference of the one of the at least one pin hole, the expansion member having an inner circumferential surface that, in response to a first power, selectively holds or releases an outer circumferential surface of the lift pin.