Electrostatic Chuck Pixelated Light Heating

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Solution Overview

Problem

Conventional electrostatic chucks in plasma processing chambers face challenges in achieving uniform temperature control due to limitations in response time and power loads, leading to cold and hot spots, which are exacerbated by RF environments and auxiliary hardware non-uniformities.

Innovation Solution

The implementation of a pixelated light-based heating system within the electrostatic chuck, utilizing a ceramic plate with a light carrying medium and control system to provide precise temperature control, reducing the need for additional electrical connections and mitigating RF interface issues.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If conventional heat transfer fluid loops are used for temperature control, then heating and cooling power can be provided, but response time is slow due to long line lengths and large fluid volumes

Engineering Contradiction:

Improvetemperature control response timeVSAvoidheat transfer fluid volume

Core Design Contradiction:

SpeedVSQuantity of substance

Solution Approach 1:

The patent replaces the mechanical heat transfer fluid loop system with a light-based heating system. Optical fibers deliver light energy directly to the chuck, eliminating the need for large volumes of heat transfer fluid and long line lengths, thereby achieving fast temperature control response times while reducing fluid volume requirements.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Speed

If point-of-use heating systems are implemented to reduce fluid loop lengths, then response time improves, but power load capacity is limited by physical space constraints

Engineering Contradiction:

Improvetemperature control response timeVSAvoidpower load capacity

Core Design Contradiction:

SpeedVSPower

Solution Approach 1:

The electrostatic chuck is designed to perform multiple functions: it provides electrostatic clamping for substrate holding, temperature control through integrated heating elements, and now also serves as a platform for light-based heating via optical fibers. This multi-functionality allows the system to achieve both fast response times and high power load capacity within the same physical space.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Power

If additional electrical heaters are added for temperature control, then heating capability improves, but RF interface issues and non-uniformities are exacerbated

Engineering Contradiction:

Improveheating powerVSAvoidRF interface stability

Core Design Contradiction:

PowerVSReliability

Solution Approach 1:

The patent substitutes electrical heating elements with light-based heating delivered through optical fibers. This replacement eliminates the RF interface issues associated with additional electrical connections and heaters, as the optical fiber system does not require electrical connections within the RF environment, thereby improving RF stability while maintaining heating capability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

4Temperature

If conventional heating systems are used, then basic temperature control is achieved, but uniformity across the substrate is poor due to cold and hot spots

Engineering Contradiction:

Improvetemperature uniformityVSAvoidtemperature distribution uniformity

Core Design Contradiction:

TemperatureVSManufacturing precision

Solution Approach 1:

The patent segments the heating function into multiple independent optical fiber channels distributed across the chuck surface. Each fiber can be independently controlled to deliver heat to specific regions, allowing for precise temperature uniformity control across the substrate and eliminating cold and hot spots through localized heating adjustment.

Inventive Principle:

Principle #1Segmentation

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 solution achieves less than 1 degree non-uniformity across a 300 mm plate, enhancing temperature and RF uniformity, and allowing for fine-tuned heating of specific areas, thereby improving etch processing efficiency.

Implementation Method 1

A light carrying medium is disposed in the base, the light carrying medium configured to provide pixelated light-based heating capability for the ESC

Methodology Applied

Scientific EffectLight-based heating: Absorption (EM radiation)

Data Source

PatentUS9196514B2Electrostatic chuck with variable pixilated heating

Publication Date: 2015.11.24 APPLIED MATERIALS INC

AI summary

Electrostatic chucks with variable pixelated heating are described. For example, an electrostatic chuck (ESC) includes a ceramic plate having a front surface and a back surface, the front surface for supporting a wafer or substrate. A base is coupled to the back surface of the ceramic plate. A light carrying medium is disposed in the base, the light carrying medium configured to provide pixelated light-based heating capability for the ESC.