Wafer And Focus Ring Alignment Using Shared Edge Sensing
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Solution Overview
Problem
Existing substrate transport systems face challenges in accurately adjusting the posture and position of both semiconductor wafers and focus rings during plasma processing, as they require precise alignment and handling to prevent deviations and ensure effective processing.
Innovation Solution
An alignment apparatus with a rotational support, edge sensor, and control circuitry that rotates and adjusts the posture of substrates and focus rings around a central axis, using edge signals to calculate and correct their center positions, allowing for precise alignment and handling by a transfer robot.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a rotational support with multiple substrate supports and ring supports is used to concurrently support and align both substrates and focus rings, then alignment precision and handling efficiency are improved, but device complexity increases
Solution Approach 1:
The rotational support is designed with both substrate supports and ring supports that can concurrently support different types of workpieces (substrates and focus rings). The same rotational support structure, rotation actuator, and edge sensor system are used for both substrate alignment and focus ring alignment, making the device multi-functional and reducing the need for separate alignment systems for each workpiece type.
2Manufacturing precision
If edge sensors are used to detect edge positions and generate edge signals for posture adjustment, then manufacturing precision is improved, but device complexity and measurement difficulty increase
Solution Approach 1:
The edge sensor automatically detects the edge position of the workpiece and generates an edge signal that is directly used by the control circuitry to control the rotation actuator for posture adjustment. The system uses its own detection capability to automatically correct alignment without requiring external measurement equipment or manual intervention, making the precision measurement and correction self-contained.
3Manufacturing precision
If the rotational support rotates to adjust posture based on edge signals, then alignment accuracy is improved, but processing time increases due to rotation and measurement steps
Solution Approach 1:
The edge sensor detects the edge position and generates the edge signal before the final posture adjustment is made. The rotation actuator then uses this pre-acquired information to make the necessary rotational adjustment to achieve the target posture. This preliminary detection and signal generation allows the system to plan and execute the alignment correction efficiently without repeated measurements during the adjustment process.
Data Source
AI summary
An alignment apparatus includes a rotational support configured to rotate around a central axis, a rotation actuator, an edge sensor, and control circuitry. The rotational support includes substrate supports configured to concurrently support a substrate, and ring supports configured to concurrently support a focus ring. The rotation actuator is configured to rotate the rotational support around the central axis. The edge sensor is configured to generate an edge signal that changes in accordance with each of an edge position of the substrate and an edge position of the focus ring. The control circuitry is configured to control the rotation actuator to adjust a posture of the substrate to a first target posture based on the edge signal, and to control the rotation actuator to adjust a posture of the focus ring to a second target posture based on the edge signal.