Virtual Metrology for Chamber Window Temperature Control
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Solution Overview
Problem
In semiconductor manufacturing, unwanted window coatings on the transparent chamber surfaces of epitaxy or chemical vapor deposition (CVD) chambers lead to particle contamination and reduced transparency, potentially causing permanent loss of transparency in quartz windows at high temperatures.
Innovation Solution
A substrate processing system that includes a pyrometer for temperature measurement, a controller for estimating temperatures at multiple locations and adjusting system operations, and a digital twin model to emulate chamber components and processes, along with a chamber conditioning assembly using variable speed blowers and flow modulators to manage air flows and temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If window temperature is increased to improve processing efficiency, then productivity is improved, but window coating accumulates faster and transparency is reduced
Solution Approach 1:
The system performs preliminary cooling of the window surface before coating accumulation becomes problematic. The controller monitors temperature and activates the blower to maintain window temperature below the coating deposition threshold, preventing harmful coating accumulation before it occurs.
Solution Approach 2:
The system uses temperature sensors to continuously monitor window temperature and feeds this information back to the controller. The controller adjusts the blower operation based on this feedback to maintain optimal temperature, balancing processing efficiency with prevention of coating accumulation.
2Productivity
If window temperature exceeds threshold to accelerate processing, then productivity is improved, but window transparency is permanently lost
Solution Approach 1:
The system takes preliminary action by actively cooling the window surface during processing to keep temperature below the 900°C threshold. This prevents the irreversible loss of transparency while still allowing efficient processing to occur.
Solution Approach 2:
The system provides beforehand cushioning by using the blower to remove heat from the window surface before the temperature can reach levels that would cause permanent damage. This protective measure cushions against the harmful effect of excessive heating.
3Device complexity
If single-point temperature measurement is used to simplify monitoring, then device complexity is reduced, but temperature distribution control is insufficient
Solution Approach 1:
The system uses a digital twin model that creates a virtual copy of the physical chamber. This digital model simulates and predicts temperature distribution across the entire chamber based on limited sensor data, providing comprehensive temperature information without requiring multiple physical sensors throughout the chamber.
Solution Approach 2:
The system replaces a mechanical approach (multiple physical temperature sensors distributed throughout the chamber) with a computational approach (digital twin simulation). This substitution reduces device complexity while improving temperature distribution control through predictive modeling.
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 effectively monitors, predicts, and controls temperature to prevent unwanted window coatings, reducing particle contamination and maintaining window transparency, thereby ensuring reliable and efficient semiconductor processing.
Implementation Method 1
a pyrometer to take a temperature measurement of a first location of the chamber body
Implementation Method 2
one or more variable speed blowers configured to supply an air flow to a chamber body. The assembly also includes a first mechanical flow configured to direct a first air flow stream towards a central region of the chamber body, and a second mechanical flow modulator configured to direct a second air flow stream towards a periphery region of the chamber body
Data Source
AI summary
Embodiments of the disclosure relate to a substrate processing system with improved thermal management. The substrate processing system utilizes a pyrometer for temperature measurement on the outer surface of a chamber body, and a controller to adjust operations based on estimated temperatures at various locations on the inner surface of a chamber body. The system employs a digital twin model, potentially physics-based, data-based, or a hybrid, to simulate process runs and generate temperature mappings inside the chamber body. The chamber structure features a chamber body made from high IR transmission materials and includes a chamber conditioning assembly with variable speed blowers and mechanical flow modulators. The associated method manipulates the system with the digital twin model and the chamber conditioning assembly for enhanced temperature control. Furthermore, an apparatus is presented, equipped with mechanical flow modulators directing air flows for effective thermal regulation, migrating unwanted window coating.