Linear-Parallel Cooling Channels for Electrostatic Chuck Temperature Uniformity

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Solution Overview

Problem

Typical electrostatic chuck (ESC) assemblies in semiconductor manufacturing tools lack uniform and rapid cooling for wafers due to their spiral cooling channel design, which results in temperature inconsistencies across the wafer support area.

Innovation Solution

The support pedestal device features a base housing with internal linear-parallel cooling channels and fins, allowing for efficient fluid flow through supply and return channels, directing the cooling fluid radially and bi-circumferentially to enhance thermal conductivity and reduce thermal mass, thereby improving temperature control across the wafer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If a spiral cooling channel design is used in the ESC assembly, then the cooling fluid can circulate through the chuck base, but the flow path becomes relatively long and temperature uniformity deteriorates

Engineering Contradiction:
Improvecooling efficiencyVSAvoidtemperature uniformity
Core Design Contradiction:
Loss of energyVSTemperature

Solution Approach 1:

The patent divides the cooling channel into multiple straight parallel segments separated by cooling fins, replacing the single spiral channel. This segmentation creates multiple independent cooling paths that are shorter and more direct, improving both cooling efficiency and temperature uniformity across the wafer support surface.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces cooling fins that extend vertically from the chuck base, creating a three-dimensional cooling structure. This adds a vertical dimension to the cooling architecture, increasing the cooling surface area and enabling more effective heat dissipation while maintaining compact horizontal dimensions.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Productivity

If a spiral cooling channel is used, then the cooling fluid can be circulated, but the flow path length increases causing reduced cooling performance

Engineering Contradiction:
Improvecooling performanceVSAvoidflow path length
Core Design Contradiction:
ProductivityVSLength of moving object

Solution Approach 1:

The cooling system is segmented into multiple straight parallel channels instead of a single spiral path. Each channel provides a direct, short flow path from inlet to outlet, eliminating the long circumferential path of the spiral design and reducing total fluid travel distance while maintaining effective cooling coverage.

Inventive Principle:
Principle #1Segmentation

3Strength

If neighboring layers are bonded with thermally conductive elastomer adhesive, then the layers can be joined, but thermal resistance increases

Engineering Contradiction:
Improvebond strengthVSAvoidthermal resistance
Core Design Contradiction:
StrengthVSLoss of energy

Solution Approach 1:

The patent applies thermally conductive elastomer adhesive only at specific bonding interfaces between layers where mechanical strength is required, rather than throughout the entire cooling channel path. This localized application minimizes the introduction of thermal resistance while maintaining necessary structural bonds.

Inventive Principle:
Principle #3Local quality

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 design achieves a 30% increase in thermal transfer efficiency by maintaining a more uniform temperature and reducing thermal resistance, allowing for better responsiveness to heat loads with reduced back pressure and increased convection.

Implementation Method 1

A cooling fluid is able to flow through the fluid pathway by passing through the fluid supply channel, through the plurality of linear-parallel cooling channels, and back through the fluid return channel to cool the support pedestal device

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

directing the cooling fluid through linear-parallel cooling channels; directing the cooing fluid inward radially through a fluid return channel to the central portion

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP3304584B1High thermal conductivity wafer support pedestal device
Publication Date: 2019.12.04 WATLOW ELECTRIC MANUFACTURING CO
  • EP3304584B1 patent drawingFigure 1
  • EP3304584B1 patent drawingFigure 2~3
  • EP3304584B1 patent drawingFigure 4

AI summary

A support pedestal device for an electrostatic chuck includes a base housing defining an internal cavity, and a base insert disposed proximate the internal cavity of the base housing. A fluid pathway is formed in the internal cavity and includes a plurality of linear-parallel cooling channels separated by corresponding plurality of linear-parallel cooling fins, a fluid supply channel, and a fluid return channel. A cooling fluid flows through the fluid supply channel, through the plurality of linear- parallel cooling channels, and back through the fluid return channel to cool the support pedestal device.