Wafer Chuck Alignment Sensor Using Edge Ring Imaging
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Solution Overview
Problem
The accuracy of substrate processing in semiconductor manufacturing is compromised due to improper seating of wafers on electrostatic chucks in process chambers, affecting the reliability of various processes such as photolithography, etching, ashing, ion implantation, and thin film deposition.
Innovation Solution
A substrate processing apparatus with a substrate alignment sensor that includes a body, imaging unit, and control unit to accurately align the substrate with a substrate support unit, utilizing edge ring geometry and multiple imaging units to calculate and adjust spacing for precise alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a substrate alignment sensor is installed on the substrate support unit to improve alignment accuracy, then manufacturing precision is improved, but device complexity increases due to additional components like imaging units and control systems
Solution Approach 1:
The patent uses an imaging unit to capture optical images of the substrate and edge ring, creating a visual copy of the physical arrangement. This allows the control unit to calculate spacing and alignment based on image analysis rather than complex physical measurements, improving alignment accuracy while managing system complexity through optical copying methods
Solution Approach 2:
The edge ring serves as an intermediary element between the substrate and substrate support unit. It provides a reference structure that the imaging unit can detect and use to calculate spacing. This intermediary simplifies the alignment process by providing a measurable reference point that mediates between the substrate position and the support unit geometry
2Manufacturing precision
If multiple imaging units are used to capture images from different directions to improve alignment precision, then manufacturing precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent employs multiple imaging units positioned at different locations (front, rear, left, right sides) to capture images from multiple dimensions. This multi-dimensional imaging approach allows the control unit to calculate spacing more accurately by comparing views from different angles, improving alignment precision through dimensional diversity
Solution Approach 2:
The imaging system is segmented into multiple independent imaging units rather than using a single complex camera system. Each imaging unit captures images from its specific position, and the control unit integrates this segmented information to achieve precise alignment calculations, dividing the complex imaging task into manageable segments
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
Enhances the reliability of substrate processing by ensuring proper seating of wafers on electrostatic chucks, improving the accuracy and consistency of processes like etching, deposition, and cleaning.
Implementation Method 1
The imaging unit may be on a bottom surface of the body and configured to image an upper surface of the edge ring and a sidewall of the body
Data Source
AI summary
A substrate processing apparatus may include a substrate support unit in a lower portion of a process chamber; an edge ring on and along an edge of an upper surface of the substrate support unit and protruding from the upper surface of the substrate support unit; and a substrate alignment sensor on the substrate support unit. The substrate alignment sensor may include a body, an imaging unit, and a control unit. The imaging unit may be on a bottom surface of the body and configured to image a sidewall of the edge ring and a sidewall of the body. The control unit may be configured to control the imaging unit and calculate a spacing between the sidewall of the edge ring and the sidewall of the body. The control unit may be configured to align the substrate alignment sensor with the substrate support unit based on the spacing.