Pyrometer-Based Wafer Decentering Detection During Layer Deposition
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Solution Overview
Problem
Existing semiconductor processing systems face challenges in accurately determining substrate centering during material layer deposition, which can lead to cross-substrate variation in material layer thickness and dopant concentration, potentially causing substrate damage and process inefficiencies.
Innovation Solution
A semiconductor processing system is designed with a pyrometer radially offset from the rotation axis, capable of acquiring temperature measurements using electromagnetic radiation emitted by the substrate. The system determines decentering by analyzing temperature differences, standard deviations, and oscillation amplitudes of these measurements, allowing for precise substrate centering adjustments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If imaging devices are used to determine substrate placement accuracy, then measurement capability is improved, but device complexity increases
Solution Approach 1:
The patent replaces complex imaging devices with a pyrometer-based thermal measurement system. The pyrometer measures temperature variations at different radial positions on the substrate, and these thermal signals are used to calculate decentering. This substitutes optical/mechanical imaging complexity with simpler thermal sensing and mathematical computation.
Solution Approach 2:
The patent introduces temperature as an intermediary parameter to indirectly measure substrate placement accuracy. Instead of directly imaging the substrate position, the system measures temperature distribution caused by decentering and uses this thermal signature to determine placement error, simplifying the measurement approach.
2Measurement precision
If load cells are used to monitor substrate centering, then measurement capability is improved, but device complexity increases
Solution Approach 1:
The patent replaces mechanical load cells with a thermal measurement system. Instead of using physical sensors to detect weight distribution and infer centering, the pyrometer measures temperature variations that result from decentering, eliminating mechanical components and reducing system complexity.
Solution Approach 2:
Temperature serves as an intermediary that translates mechanical decentering into a measurable thermal signal. The system does not directly measure mechanical position but uses temperature distribution as a proxy, simplifying the measurement mechanism.
3Measurement precision
If automatic wafer centering sensors are used, then measurement capability is improved, but device complexity increases
Solution Approach 1:
The patent replaces specialized automatic wafer centering sensors with a pyrometer and computational algorithm. The thermal measurement system combined with mathematical processing of temperature data substitutes dedicated mechanical sensing hardware, reducing device complexity.
Solution Approach 2:
The pyrometer serves multiple functions: it monitors substrate temperature during processing and simultaneously detects decentering conditions. This multi-functionality eliminates the need for separate centering sensors, reducing overall system complexity.
4Device complexity
If decentering detection is not implemented, then device complexity is reduced, but manufacturing precision deteriorates
Solution Approach 1:
The system performs preliminary detection of decentering conditions before material layer deposition begins. By measuring temperature distribution and calculating decentering in advance, the system can identify and correct positioning issues before they affect manufacturing precision, preventing thickness variations.
Solution Approach 2:
The pyrometer provides real-time feedback on substrate positioning accuracy through temperature measurements. This feedback loop allows the system to detect decentering and adjust substrate position or processing parameters to maintain manufacturing precision.
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 reduces cross-substrate variation in material layer deposition, enhances substrate positioning accuracy, and minimizes the risk of substrate damage, thereby improving the overall efficiency and reliability of semiconductor processing.
Implementation Method 1
acquire a temperature measurement acquired using electromagnetic radiation emitted by the substrate
Data Source
AI summary
A semiconductor processing system includes a chamber body, a substrate support, a pyrometer, and a controller. The substrate support is arranged within an interior of the chamber body and is supported for rotation about a rotation axis. The pyrometer is supported above the chamber body, is radially offset from the rotation axis, and is optically coupled to the interior of the chamber body. The controller is operably connected to the substrate support and is disposed in communication with the pyrometer. The controller is further responsive to instructions recorded on a non-transitory machine-readable memory to seat a substrate on the substrate support, acquire a temperature measurement acquired using electromagnetic radiation emitted by the substrate, and determine decentering of the substrate relative to the rotation axis using the electromagnetic radiation received at the pyrometer. Material layer deposition methods and computer program products are also described.