Wafer Edge Pyrometer Alignment for Uniform Reactor Heating
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Solution Overview
Problem
Existing semiconductor processing systems face challenges in accurately measuring and controlling wafer temperatures, particularly at the far edge, leading to nonuniform temperature distributions and potential defects in epitaxial films due to localized heating by infrared lamps.
Innovation Solution
A reactor system with a pyrometer mounting assembly and alignment jig is used to support and position infrared (IR) pyrometers to measure center and edge temperatures, utilizing a fiber optic sensor to ensure accurate alignment of the pyrometer with the lamp bank.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If infrared lamps are used for radiant heating, then heating efficiency is improved, but temperature uniformity deteriorates due to localized hot spots
Solution Approach 1:
The patent applies local quality by using multiple infrared lamps positioned at different locations (front, center, rear) to provide localized heating zones that collectively achieve uniform temperature distribution across the wafer surface, preventing hot spots while maintaining high heating efficiency
Solution Approach 2:
The heating system is segmented into multiple independent infrared lamp units positioned at different locations, allowing each lamp to contribute to specific regions of the wafer, thereby achieving both efficient localized heating and overall temperature uniformity
2Measurement precision
If pyrometers are added for temperature monitoring, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The pyrometer system is integrated with the existing lamp bank structure, allowing the same optical path and mounting mechanism to serve both heating and temperature monitoring functions, thereby reducing overall system complexity while maintaining high measurement precision
Solution Approach 2:
The patent merges the temperature monitoring function with the heating system by positioning pyrometers to share the optical path through the lamp bank, combining multiple functions into a unified system that reduces complexity while improving measurement capability
3Manufacturing precision
If alignment jig is used for pyrometer positioning, then manufacturing precision is improved, but device complexity increases
Solution Approach 1:
The alignment jig is designed to pre-position the pyrometer at the correct location and orientation before final installation, ensuring high positioning precision while simplifying the overall assembly process by separating alignment and mounting operations
Solution Approach 2:
The alignment jig acts as an intermediary tool that facilitates precise pyrometer positioning during assembly, transferring alignment information from the lamp bank structure to the pyrometer without requiring complex direct mounting mechanisms
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 includes a pyrometer mounting assembly to accurately monitor both center and edge temperatures, ensuring uniform temperature distribution and reducing thermal gradients, thereby improving the quality of deposited films.
Implementation Method 1
infrared (IR) pyrometers to measure center and edge temperatures
Implementation Method 2
utilizing a fiber optic sensor to ensure accurate alignment of the pyrometer with the lamp bank
Implementation Method 3
radiant heating... positioning infrared lamps around a reaction chamber or reactor containing the substrate
Data Source
AI summary
A reactor system designed to provide accurate monitoring of wafer temperatures during deposition steps. The reactor system includes a pyrometer mounting assembly supporting and positioning three or more pyrometers (e.g., infrared (IR) pyrometers) relative to the reaction chamber to measure a center wafer temperature and an edge wafer temperature as well as reaction chamber temperature. The pyrometer mounting assembly provides a small spot size or temperature sensing area with the edge pyrometer to accurately measure edge wafer temperatures. A jig assembly, and installation method for each tool setup, is provided for use in achieving accurate alignment of the IR pyrometer sensing spot (and the edge pyrometer) relative to the wafer, when the pyrometer mounting assembly is mounted upon a lamp bank in the reactor system or in tool setup. The wafer edge temperature sensing with the reactor system assembled with proper alignment ensures accurate and repeatable measurement of wafer temperatures.