Plasma Event Localization in Multi-Station Fabrication Chambers
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Solution Overview
Problem
Anomalous plasma events during wafer fabrication processes can cause damage to wafers and fabrication chambers, and existing detection methods are inadequate for timely and accurate identification of the affected station.
Innovation Solution
A multi-station integrated circuit fabrication chamber equipped with viewports for optical emissions and photosensors to detect these emissions, along with a processor that identifies anomalous plasma events by analyzing output signals from multiple photosensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple photosensors are used to detect optical emissions from multiple stations, then the precision of identifying the affected station is improved, but the complexity of the detection system increases
Solution Approach 1:
The detection system is segmented into multiple photosensors, each assigned to monitor specific stations. Each photosensor detects optical emissions from one or more stations independently, allowing precise identification of the affected station while maintaining manageable system complexity through modular architecture
Solution Approach 2:
Each photosensor is designed to be multi-functional, capable of detecting optical emissions from multiple different stations. This universal detection capability allows a single photosensor type to serve multiple monitoring functions across different stations, improving identification precision without proportionally increasing system complexity
2Speed
If viewports are positioned to allow observation of multiple stations, then the speed of detecting anomalous plasma events is improved, but the structural complexity of the fabrication chamber increases
Solution Approach 1:
Multiple viewports are strategically positioned and combined to provide overlapping fields of view that cover multiple stations simultaneously. This merging of observation paths allows a single photosensor to monitor multiple stations, improving detection speed while minimizing additional structural complexity by sharing viewport infrastructure
Solution Approach 2:
Viewports are positioned in three-dimensional space to create angular coverage of multiple stations. By utilizing spatial dimensionality, the system achieves multi-station observation capability without requiring additional viewports in every possible location, thus improving detection speed while controlling structural complexity
3Measurement precision
If the processor analyzes output signals from multiple photosensors to identify the affected station, then the accuracy of event location is improved, but the processing time increases
Solution Approach 1:
The processor is pre-configured with knowledge of which photosensors monitor which stations. When optical emissions are detected, the processor immediately knows which photosensor signals to analyze and can directly identify the affected station without requiring complex real-time analysis of all sensor data, thus improving location accuracy while minimizing processing time
Solution Approach 2:
The system implements feedback through the processor that continuously monitors photosensor output signals and immediately identifies anomalies. When an anomalous plasma event is detected, the feedback mechanism rapidly correlates the signal source with the specific station, improving event location accuracy while maintaining fast response through efficient feedback loops
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 rapid detection and location of anomalous plasma events, minimizing damage to wafers and fabrication chambers by allowing for immediate adjustments to the RF power source and facilitating targeted metrology processes.
Implementation Method 1
a plurality of photosensors. Each sensor of the plurality of photosensors is arranged proximate to a corresponding one of the plurality of viewports, to detect the optical emissions that emanate from the at least one station
Data Source
AI summary
An apparatus to determine occurrence of an anomalous plasma event occurring at or near a process station of a multi-station integrated circuit fabrication chamber is disclosed. In particular embodiments, optical emissions generated responsive to the anomalous plasma event may be detected by at least one photosensor of a plurality of photosensors. A processor may cooperate with the plurality of photosensors to determine that the anomalous plasma event has occurred at or near by a particular process station of the multi-station integrated circuit fabrication chamber.