Electrostatic Chuck Charge Dissipation Structure for Faster Wafer Release

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Solution Overview

Problem

Existing electrostatic chucks experience a delay in charge dissipation from the workpiece after the electrode is powered down, leading to decreased process throughput and potential wafer damage due to residual electrostatic forces.

Innovation Solution

An electrostatic chuck design with a multi-layer charge dissipation structure comprising a highly-conductive layer and a less conductive top layer, featuring an array of interconnected topographies and embossments, which efficiently removes electrostatic charge while minimizing interference with the clamping function.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If a single-layer highly-conductive charge dissipation structure is used, then charge dissipation speed is improved, but interference with the clamping function increases

Engineering Contradiction:

Improvecharge dissipation speedVSAvoidinterference with clamping function

Core Design Contradiction:

SpeedVSObject-affected harmful factors

Solution Approach 1:

The patent applies composite materials by combining two conductive layers with different resistivities. The first layer (higher resistivity) minimizes interference with clamping, while the second layer (lower resistivity) enhances charge dissipation. This composite structure resolves the contradiction by allowing each layer to perform its specialized function without compromising the other.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent implements local quality by creating spatial variation in conductive properties through the two-layer structure. The first layer provides distributed, higher-resistivity coverage across the chuck surface to minimize clamping interference, while the second layer provides targeted, lower-resistivity pathways for rapid charge dissipation. This local differentiation of conductive quality resolves the contradiction between dissipation speed and clamping interference.

Inventive Principle:

Principle #3Local quality

2Reliability

If a conductive charge dissipation structure is added, then charge dissipation capability is improved, but device complexity increases

Engineering Contradiction:

Improvecharge dissipation capabilityVSAvoidchuck structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The charge dissipation structure serves multiple functions: it provides charge dissipation pathways, maintains electrical isolation between the chuck and workpiece during clamping, and does not interfere with the clamping force distribution. By making the structure multi-functional, the patent justifies the added complexity through enhanced reliability and performance.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent manages complexity by controlling the electrical parameters (resistivity) of the conductive layers rather than adding complex mechanical or structural elements. By adjusting the resistivity values of the two layers, the system achieves effective charge dissipation while maintaining compatibility with the existing clamping mechanism, thus limiting the increase in overall device complexity.

Inventive Principle:

Principle #35Parameter changes

3Stability of the object's composition

If charge dissipation is delayed, then clamping stability is maintained, but process throughput decreases

Engineering Contradiction:

Improveclamping stabilityVSAvoidprocess throughput

Core Design Contradiction:

Stability of the object's compositionVSProductivity

Solution Approach 1:

The patent enables periodic or cyclic operation by facilitating rapid charge dissipation when needed. The two-layer conductive structure allows the system to quickly transition from charged (clamping) state to discharged (release) state, enabling faster cycle times and improved throughput while maintaining stability during the clamping phase through controlled charge distribution.

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

The design ensures rapid charge dissipation, reducing the delay in removing electrostatic forces, thereby enhancing process throughput and preventing wafer damage by minimizing contamination and interference with the clamping action.

Implementation Method 1

a first conductive layer on the insulating layer having a first resistivity, and a second conductive layer over the first conductive layer, having a second resistivity, wherein the second the resistivity is higher than the first resistivity

Methodology Applied

Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 2

A voltage is applied to electrodes that are contained within the multi-layer structure of the chuck to induce charges of opposite polarities in the workpiece and the chuck

Methodology Applied

Scientific EffectElectrostatic induction: Electrostatic Induction

Implementation Method 3

The electrostatic chuck secures the workpiece to an upper surface of the chuck by creating an electrostatic attractive force between the workpiece and the chuck

Methodology Applied

Scientific EffectElectrostatic attraction: Electrostatics

Data Source

PatentUS12444636B2Electrostatic chuck with a charge dissipation structure

Publication Date: 2025.10.14 ENTEGRIS INC

AI summary

Described are electrostatic chucks that are useful to support a workpiece during a step of processing the workpiece, the electrostatic chuck including a pattern of charge dissipation lines on an insulating layer, the lines having a first conductive layer and a second conductive layer and being arranged to define enclosed fields of the insulating layer between the lines.