Single Beam-Shaping Channel for Multi-Azimuth Wafer Inspection
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Solution Overview
Problem
Conventional semiconductor inspection systems using multiple azimuthal angles require separate beam-shaping channels, leading to increased complexity, cost, and stability issues due to multiple optical and mechanical components.
Innovation Solution
A single beam-shaping channel is used to generate multiple azimuthal angles by rotating, translating, and/or swapping diffractive optical elements and other optics, allowing for an infinite number of azimuthal angles without the need for multiple channels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If separate and independent beam-shaping channels are used for each illumination beam to provide multiple azimuthal angles, then measurement precision and noise reduction are improved, but device complexity and cost increase
Solution Approach 1:
A single beam-shaping channel is designed to perform multiple functions by generating multiple independent illumination beams at different azimuthal angles through diffractive optical elements. This universal channel replaces what would traditionally require multiple separate beam-shaping channels, reducing system complexity while maintaining the capability to illuminate the wafer from multiple angles for high-fidelity inspection
Solution Approach 2:
Multiple beam-shaping channels are merged into a single integrated beam-shaping channel that uses diffractive optical elements to split and shape the illumination beam into multiple independent beams. This combining approach maintains the functional equivalence of multiple channels while reducing the overall number of components and simplifying the system architecture
2Adaptability or versatility
If separate and independent beam-shaping channels are used for each illumination beam, then multiple azimuthal angles are achieved, but cost increases
Solution Approach 1:
The single beam-shaping channel incorporates diffractive optical elements that enable it to generate illumination beams at multiple azimuthal angles (e.g., 0°, 45°, 90°, 135°) simultaneously. This multi-functional design eliminates the need for multiple separate channels, thereby reducing the overall system cost while maintaining adaptability to inspect from various angles
3Adaptability or versatility
If multiple independent beam-shaping channels are used, then multiple azimuthal angles are provided, but stability deteriorates due to multiple optical and mechanical components
Solution Approach 1:
Multiple independent beam-shaping channels are merged into a single integrated channel with fewer optical and mechanical components. This reduction in component count directly improves system stability and reliability, as there are fewer potential failure points while still achieving multiple azimuthal angles through the diffractive optical element design
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
This approach reduces system complexity and cost while maintaining high inspection accuracy by adjusting a single beam-shaping channel to achieve various azimuthal angles, improving ease of assembly and serviceability.
Implementation Method 1
The diffractive optical element may be configured to be rotated around an axis of the illumination beam
Implementation Method 2
The diffractive optical element may include a Fresnel zone plate (FZP) offset from the axis of the illumination beam
Data Source
AI summary
An inspection system and method are disclosed. The inspection system may include a controller configured to be communicatively coupled to an optical sub-system. The controller may include one or more processors configured to execute program instructions to cause the one or more processors to direct a stage to perform a first scanning of a sample using a first configuration of a beam-shaping channel, where the first configuration controls an orientation of a beam profile of an illumination beam as projected onto the sample; receive first scan data associated with the first scanning; direct the stage to perform a second scanning using a second configuration of the beam-shaping channel; receive second scan data associated with the second scanning; and identify one or more defects on the sample based on scan data from at least the first and second scans. The stage may include an X-Y θ stage.