Dual Pyrometer Wafer Heating for Multi-Zone Temperature Uniformity

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Solution Overview

Problem

Existing single-zone temperature control methods in semiconductor processing result in non-uniform temperature distributions across substrates, leading to uneven film deposition and undesirable crystallographic slip, particularly affecting the substrate edge due to varying emissivity and thermal profiles.

Innovation Solution

Implementing a dual-zone temperature control system using two pyrometers to monitor and control the center and edge zones of a substrate, with independent power adjustment of heater elements based on real-time temperature feedback to achieve precise temperature differentials.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If radiant heating with localized infrared lamps is used to heat substrates, then heating efficiency is improved, but temperature uniformity across the substrate deteriorates due to hot spots and interference effects

Engineering Contradiction:

Improveheating efficiencyVSAvoidtemperature uniformity

Core Design Contradiction:

Use of energy by moving objectVSTemperature

Solution Approach 1:

The heating system is divided into multiple independent radiant heating zones, each with its own infrared lamps and pyrometer for temperature monitoring. This segmentation allows independent control of temperature in different substrate regions, enabling uniform heating across the entire substrate while maintaining high heating efficiency in each zone

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Each radiant heating zone is equipped with independent temperature control through localized pyrometers that monitor specific regions of the substrate. This local quality approach allows different parts of the substrate to receive tailored heating conditions, compensating for variations in emissivity and thermal properties across the substrate surface

Inventive Principle:

Principle #3Local quality

2Device complexity

If single-zone temperature control is used to simplify the control system, then device complexity is reduced, but manufacturing precision deteriorates due to non-uniform temperature distribution causing uneven film deposition

Engineering Contradiction:

Improvecontrol system complexityVSAvoidfilm thickness uniformity

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

The control system is segmented into multiple independent temperature control zones, each with its own pyrometer and heater control. This segmentation enables precise temperature control in each zone to compensate for radial temperature gradients, achieving uniform film deposition without requiring a single complex centralized control system

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Each radiant heating zone incorporates a pyrometer that provides real-time temperature feedback for its designated substrate region. This feedback mechanism allows the control system to dynamically adjust heating power in each zone based on actual temperature conditions, ensuring uniform film thickness while maintaining manageable system complexity through modular control architecture

Inventive Principle:

Principle #23Feedback

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 approach significantly reduces within-layer and layer-to-layer film thickness variations, improving the uniformity and quality of deposited films, enhancing the manufacturing yield and throughput of semiconductor devices.

Implementation Method 1

with a first pyrometer, sensing a temperature of a first zone of a substrate supported in the reactor system, and, with a second pyrometer, sensing a temperature of a second zone of the substrate

Methodology Applied

Scientific EffectThermal radiation: Thermal Radiation

Implementation Method 2

wafers are heated using resistance heating, induction heating, or radiant heating

Methodology Applied

Scientific EffectResistance heating: Joule Heating

Implementation Method 3

In a CVD process, for example, gaseous molecules of the material to be deposited are supplied to wafers to form a thin film of that material on the wafers by chemical reaction

Methodology Applied

Scientific EffectChemical vapor deposition: Chemical Vapour Deposition

Data Source

PatentUS20260082851A1Dual pyrometer systems for substrate temperature control during film deposition

Publication Date: 2026.03.19 ASM IP HLDG BV

AI summary

A method of operating a reactor system to provide multi-zone substrate temperature control. The method includes, with a first pyrometer, sensing a temperature of a first zone of a substrate supported in the reactor system, and, with a second pyrometer, sensing a temperature of a second zone of the substrate. The method further includes, with a controller, comparing the temperatures of the first and second zones to setpoint temperatures for the first and second zones and, in response, generating control signals to control heating of the substrate. The method also includes controlling, based on the control signals, operations of a heater assembly operating to heat the substrate.