Wafer Inspection Charge Controller Using Beam Homogenizer
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Solution Overview
Problem
Current electron-beam inspection tools face challenges in detecting wafer defects due to limitations in controlling and illuminating wafers effectively, particularly as feature sizes in integrated circuits shrink below 100 nanometers, requiring higher resolution inspection systems.
Innovation Solution
The implementation of advanced charge controllers for wafer inspection, which include a beam homogenizer to create a uniform intensity profile, an anamorphic prism group to shape the laser beam, and a driver with wedges or plates to direct the beam coaxially aligned with the laser source, ensuring precise illumination and defect detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If laser beam illumination is activated to improve defect detection, then defect detection capability is improved, but beam control difficulty increases
Solution Approach 1:
The patent introduces a beam homogenizer as an intermediary component between the laser source and the wafer. This homogenizer converts the non-uniform laser beam into a uniform intensity profile, making the illumination easier to control while maintaining improved defect detection capability. The homogenizer acts as a mediator that transforms the difficult-to-control laser beam into a manageable uniform illumination source.
2Device complexity
If optical microscope is used for inspection, then inspection system is simple, but resolution is limited to a few hundred nanometers
Solution Approach 1:
The patent changes the fundamental parameter of illumination by introducing a laser source with specific wavelength and intensity characteristics. This parameter change enables the system to achieve sub-100 nanometer resolution while maintaining relative system simplicity. The laser's coherent light properties and adjustable parameters allow for high-resolution inspection without requiring complex optical microscope systems.
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 solution enhances the effectiveness of defect detection by providing improved control and illumination of wafers, allowing for more accurate inspection of sub-100 nanometer features, thereby improving the resolution and reliability of electron-beam inspection systems.
Implementation Method 1
a beam homogenizer to homogenize the emitted beam
Implementation Method 2
a beam shaper configured to shape the emitted beam using an anamorphic prism group
Implementation Method 3
an anamorphic prism group comprising a group of two or more prisms
Implementation Method 4
a mirror for reflecting the beam from the driver so that the beam intersects the wafer with a substantially circular cross section
Implementation Method 5
a laser source for emitting a beam wherein the laser source is a collimated laser
Data Source
AI summary
A system and method for advanced charge control of a light beam is provided. The system comprising a laser source comprising a laser diode for emitting a beam and a beam homogenizer to homogenize the emitted beam. The system and methods further comprise a beam shaper configured to shape the emitted beam using an anamorphic prism group and a driver configured to direct the shaped beam to a specified position on a wafer, wherein the laser source, the beam shaper, and the driver are coaxially aligned.