Ceramic Heater Assembly With Backside Heating for Center Uniformity

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Solution Overview

Problem

Conventional ceramic heater designs for semiconductor processing suffer from a cold spot at the center of the platen, leading to non-uniform temperature profiles and compromised processing quality due to the absence of heating elements in this region.

Innovation Solution

A ceramic heater assembly with internal and external heating functionality, incorporating embedded heater elements and a backside heater to deliver thermal energy to the central region, ensuring uniform heating across the platen and workpiece.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If heating elements are embedded only in the peripheral regions of the platen, then the peripheral heating zones achieve adequate temperature, but a cold spot forms at the center region of the platen

Engineering Contradiction:

Improvetemperature uniformityVSAvoidheating element configuration

Core Design Contradiction:

TemperatureVSDevice complexity

Solution Approach 1:

The heating system is divided into multiple independent heating zones: peripheral heating elements arranged in a pattern around the platen periphery, and a central heating element positioned in the center region. Each zone can be controlled independently to achieve uniform temperature distribution across the entire platen surface, eliminating the cold spot problem.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the platen are equipped with heating elements tailored to their specific thermal requirements. The peripheral regions have heating elements configured to address edge cooling effects, while the central region has a dedicated central heating element to prevent cold spot formation. This localized heating approach ensures optimal temperature uniformity across different zones.

Inventive Principle:

Principle #3Local quality

2Temperature

If heating elements are placed in the center region of the platen, then the cold spot problem is eliminated, but electrical contacts require additional space and complexity

Engineering Contradiction:

Improvecenter region temperatureVSAvoidelectrical contact arrangement

Core Design Contradiction:

TemperatureVSDevice complexity

Solution Approach 1:

The central heating element is integrated into the platen structure in a nested configuration, where the heating element is positioned within or alongside the electrical contact regions. This nesting allows the heating element and electrical contacts to share the same central space, eliminating the need for additional peripheral space and reducing overall device complexity.

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

The functions of electrical contact and heating are merged in the central region of the platen. The central heating element is electrically connected through contacts that are integrated into the same structural region, combining what would traditionally be separate functional zones into a unified central assembly, thereby simplifying the overall electrical arrangement.

Inventive Principle:

Principle #5Merging (Combining)

3Ease of manufacture

If the platen center region is reserved for electrical contacts, then electrical connections are simplified, but insufficient space prevents centrally located heating elements and creates a cold spot

Engineering Contradiction:

Improveelectrical connection simplicityVSAvoidcenter region heating

Core Design Contradiction:

Ease of manufactureVSTemperature

Solution Approach 1:

The central region of the platen is designed with differentiated local zones: an inner core area dedicated to electrical contacts and an adjacent annular region for the central heating element. This local differentiation allows both electrical connections and heating functionality to coexist in the same general region, maintaining electrical connection simplicity while enabling effective center heating to eliminate cold spots.

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

The solution effectively heats and controls the temperature in the central region of the workpiece, achieving uniform temperature distribution and improving processing quality by mitigating the cold spot issue.

Implementation Method 1

actuation of the first heater causes the heat source to output thermal energy that is transferred from the heat source to a central region of the platen in a manner effective to controllably heat the central region of the platen

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

actuation of each heating element of the one or more controllable heating elements causes each of the one or more controllable heating elements to deliver thermal energy to at least one associated heating zone of the platen

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentUS20250299983A1Ceramic heater assembly with internal and external heating functionality useful in the fabrication of microelectronic devices

Publication Date: 2025.09.25 TOKYO ELECTRON LTD

AI summary

The present invention provides a ceramic heater assembly with internal and external heating functionality. The internal heating functionality includes heater elements embedded in a heated platen as well as a backside heater deployed to deliver heat from the backside to the center region of the platen. The embedded heater elements and the backside heater cooperatively deliver thermal energy to the center region. The present invention improves an ability to heat and control temperature in the central region of a workpiece being processed.