Sensor Wafer Gap Calibration for Process Kit Erosion Tracking
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Solution Overview
Problem
Current methods for positioning and maintaining a process kit in semiconductor manufacturing are inefficient, requiring expensive and time-consuming tests to ensure proper alignment, and do not account for erosion, leading to potential defects and reduced throughput.
Innovation Solution
A sensor wafer with edge sensors is used to measure and adjust the position of a process kit relative to a support surface, allowing for rapid calibration and detection of erosion rates, enabling precise alignment and predictive adjustments without extensive downtime.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional positioning tests (etch rate tests or particle tests) are used to confirm process kit alignment, then positioning accuracy is improved, but calibration time and cost increase significantly
Solution Approach 1:
A sensor wafer is introduced as an intermediary tool between the process kit and the substrate. The sensor wafer contains sensors that directly measure the gap distance between the process kit and substrate, providing immediate positioning feedback without requiring lengthy etch rate or particle tests. This intermediary measurement system enables rapid calibration while maintaining positioning accuracy.
2Device complexity
If process kit adjustments are delayed until observable defects appear on substrates, then device complexity is reduced, but manufacturing precision deteriorates
Solution Approach 1:
The sensor wafer performs preliminary measurements of the gap distance between the process kit and substrate before actual substrate processing begins. By measuring erosion and positioning accuracy in advance, the system allows for predictive adjustments to be made before defects occur, maintaining manufacturing precision without requiring complex real-time monitoring during processing.
3Measurement precision
If process kit erosion is not monitored, then measurement precision is maintained, but productivity decreases due to unplanned downtime
Solution Approach 1:
The sensor wafer provides continuous feedback on the gap distance between the process kit and substrate, enabling real-time detection of erosion. This feedback mechanism allows operators to monitor process kit condition and schedule maintenance proactively, preventing unplanned downtime and maintaining high productivity while preserving measurement precision through consistent gap distance monitoring.
Data Source
AI summary
Embodiments disclosed herein include a method of calibrating a processing chamber. In an embodiment, the method comprises placing a sensor wafer onto a support surface in the processing chamber, wherein a process kit displaceable in the Z-direction is positioned around the support surface. In an embodiment, the method further comprises measuring a first gap distance between the sensor wafer and the process kit with a sensor on an edge surface of the sensor wafer. In an embodiment, the method further comprises displacing the process kit in the Z-direction. In an embodiment, the method further comprises measuring an additional gap distance between the sensor wafer and the process kit.