Shallow Angle IR Sensor Scanning for Substrate Temperature
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Accurately measuring the temperature of fan-out packaging wafers with heterogeneous structures using normal incidence infrared sensors is challenging due to varying emissivity and unknown customer wafer patterns, making it difficult to design and calibrate IR sensor architectures.
Innovation Solution
Positioning an infrared temperature sensor at a shallow angle relative to the substrate edge to form an optical ellipse field of view, allowing scanning of the substrate surface, and using a linear up/down slide to measure temperatures of multiple wafers in a batch, with the sensor mounted outside the process chamber adjacent to a view port and movable to scan through it.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a normal incidence infrared sensor is used to measure substrate temperature, then the measurement setup is simple, but the measurement precision is poor due to varying emissivity of heterogeneous substrate materials
Solution Approach 1:
The patent changes the viewing angle parameter from normal incidence to a shallow angle (e.g., 5-15 degrees relative to the substrate edge). This parameter change allows the optical ellipse to be formed and scanned across the substrate surface, enabling accurate temperature measurements of heterogeneous materials without requiring complex emissivity calibration for each material type.
2Productivity
If the IR sensor is fixed at a single position, then the device complexity is low, but the productivity is reduced as only one substrate can be measured at a time
Solution Approach 1:
The patent implements a movable IR sensor that can scan across multiple substrates in a batch. The sensor is positioned on a movable stage or rail system that allows it to traverse the substrate array, dynamically measuring temperatures of multiple substrates sequentially. This dynamic positioning capability enables batch processing while maintaining measurement accuracy.
Solution Approach 2:
The patent introduces spatial scanning in addition to the shallow angle viewing geometry. By moving the sensor along a scan path parallel to the substrate edges, the system adds a dimensional aspect to the measurement process, enabling coverage of multiple substrates without requiring complex multi-sensor arrays.
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
Enables accurate temperature measurement of substrates during processing, preventing warping and ensuring precise control of temperature conditions within the processing volume, even for substrates with varying materials and patterns.
Implementation Method 1
an infrared temperature sensor (IRTS) disposed outside the chamber body adjacent the view port to measure a temperature of the substrate when being processed in the processing volume
Data Source
AI summary
Methods and apparatus for processing a substrate are provided. The apparatus, for example, can include a process chamber comprising a chamber body defining a processing volume and having a view port coupled to the chamber body; a substrate support disposed within the processing volume and having a support surface to support a substrate; and an infrared temperature sensor (IRTS) disposed outside the chamber body adjacent the view port to measure a temperature of the substrate when being processed in the processing volume, the IRTS movable relative to the view port for scanning the substrate through the view port.