Substrate Support Backside Pyrometry for Low-Range Temperature Sensing
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Solution Overview
Problem
Existing non-contact temperature monitoring systems for semiconductor substrates are not viable due to high costs and challenges in measuring wide temperature ranges, particularly failing to detect low temperature ranges effectively in thermal processes like CVD, PVD, and ALD.
Innovation Solution
A non-contact temperature monitoring system using a substrate support with a pedestal hub and viewport, where electromagnetic energy from the back surface of the substrate support is measured by a sensor to generate intensity signals, allowing for accurate temperature determination across a wide range without direct contact, thereby improving temperature measurement repeatability and energy efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If direct contact devices such as thermocouples are used to measure substrate support temperature, then temperature measurement is achieved, but thermal drain is created affecting temperature uniformity and energy delivery efficiency
Solution Approach 1:
The patent replaces mechanical contact-based temperature measurement (thermocouples) with non-contact optical measurement using a pyrometer. The pyrometer measures thermal radiation from the substrate support back surface through a viewport, eliminating physical contact and the associated thermal drain while maintaining measurement capability across wide temperature ranges.
2Reliability
If traditional pyrometers are used for non-contact temperature measurement, then cost is reduced and contactless measurement is achieved, but low temperature ranges cannot be detected
Solution Approach 1:
The patent modifies the pyrometer's operational parameters by adjusting its sensitivity and measurement range settings to detect low temperature ranges (including room temperature and below). The system calibrates the pyrometer to accurately measure thermal radiation at temperatures as low as -50°C, expanding the traditional pyrometer's capability which typically only measures high temperatures above 200°C.
3Measurement precision
If substrate support temperature is monitored to control processing conditions, then process control is improved, but thermal losses increase due to measurement interference
Solution Approach 1:
The patent introduces a viewport as an intermediary element that allows the pyrometer to measure temperature through the substrate support structure without direct contact. The viewport transmits thermal radiation from the back surface of the substrate support to the pyrometer sensor, enabling non-intrusive temperature monitoring that does not interfere with the thermal field or energy delivery to the substrate.
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 system provides improved temperature measurement repeatability and energy efficiency by allowing non-contact monitoring of substrate and support temperatures across a wide range, reducing thermal losses and enabling precise control in thermal processes.
Implementation Method 1
The sensor is disposed within the pedestal hub and has an input end positioned to receive electromagnetic energy emitted from the back surface of the substrate support through the viewport of the pedestal hub
Data Source
AI summary
Embodiments of the present disclosure relate to apparatus, systems and methods for substrate processing. A detachable substrate support is disposed within a processing volume of a processing chamber and the substrate support includes a substrate interfacing surface and a back surface. The pedestal hub has a supporting surface removably coupled to the substrate support. A hub volume of the pedestal hub includes temperature measuring assembly disposed therein positioned to receive electromagnetic energy emitted from the back surface of the substrate support. The temperature measuring assembly measures an intensity of the electromagnetic energy entering the assembly and generates intensity signals. An apparent temperature of the substrate is determined based on the intensity signals.