Process Chamber Thermal Calibration Using an External Blackbody
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Solution Overview
Problem
Accurately calibrating temperature sensors in semiconductor process chambers is challenging due to variations in dimensions, sensor positions, and materials, leading to costly, time-consuming, and potentially erroneous calibrations, which affect the quality of semiconductor processes.
Innovation Solution
A method and system for thermally calibrating semiconductor process chambers using a non-contact temperature sensor calibrated to match the readings of an external thermal radiation source, such as a blackbody calibration furnace, allowing for consistent calibration of additional sensors and improved temperature control across multiple process chambers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional in-situ calibration methods are used, then calibration can be performed within the process chamber, but calibration accuracy deteriorates due to variations in dimensions, sensor positions, and materials
Solution Approach 1:
The patent introduces an external thermal radiation source as an intermediary calibration target. Instead of calibrating sensors directly within the process chamber (in-situ), the sensors measure radiation from an external blackbody source with known temperature. This intermediary approach eliminates the influence of chamber dimension variations, sensor position variations, and material variations that plague in-situ calibration, thereby improving both calibration accuracy and consistency across multiple chambers.
2Ease of manufacture
If multiple process chambers are calibrated independently, then each chamber can be calibrated separately, but cascading inaccuracies occur across the system
Solution Approach 1:
The patent creates a universal calibration reference by using an external thermal radiation source that can serve multiple process chambers simultaneously. Instead of each chamber being calibrated independently with its own internal reference (which leads to cascading inaccuracies), all chambers reference the same external blackbody source. This universal reference approach maintains the ease of independent calibration while eliminating cascading errors, as each chamber's sensors are calibrated against the same known temperature standard.
3Measurement precision
If contact temperature sensors are used for calibration, then direct temperature measurement is possible, but sensor contamination and damage occur in the harsh process chamber environment
Solution Approach 1:
The patent replaces contact-based mechanical temperature measurement with non-contact optical measurement. Instead of inserting contact temperature sensors into the harsh process chamber environment where they risk contamination and damage, the system uses non-contact temperature sensors (infrared pyrometers) that measure thermal radiation from external targets. This substitution eliminates the harmful interactions between sensors and the process environment while maintaining accurate temperature measurement capability.
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 enables consistently calibrated non-contact temperature sensors, ensuring accurate temperature control and reducing the cascading inaccuracies associated with traditional in-situ calibration methods, thereby improving the quality and consistency of semiconductor processes.
Implementation Method 1
a first non-contact temperature sensor calibrated to have a first reading representative of a first temperature... obtain, through the aperture, a second reading representative of a second temperature of the blackbody calibration furnace
Data Source
AI summary
A system and method for thermally calibrating semiconductor process chambers is disclosed. In various embodiments, a first non-contact temperature sensor can be calibrated to obtain a first reading with the semiconductor process chamber. The first reading can be representative of a first temperature at a first location. The first non-contact temperature sensor can be used to obtain a second reading representative of a second temperature of an external thermal radiation source. The second temperature of the external thermal radiation source can be adjusted to a first temperature setting of the external radiation source such that the second reading substantially matches the first reading. Additional non-contact temperature sensor(s) can be directed at the external thermal radiation source and can be adjusted such that the reading(s) of the additional non-contact sensors are calibrated and matched to one another.