Microsphere Condensing Light for Semiconductor Substrate Inspection
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Solution Overview
Problem
Current semiconductor inspection technologies face challenges in achieving a smaller spot size for non-destructive three-dimensional spectral measurement, as they have reached physical and Rayleigh limits, making it difficult to improve inspection reliability with existing components.
Innovation Solution
An apparatus and method that utilize a microsphere with a diameter of about 1/300 or less than the objective lens to further condense light on a substrate, allowing for precise focal point adjustment and improved inspection reliability by using a controller to position the microsphere and objective lens vertically.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional light sources and condensing lenses are used for spectral measurement, then the inspection system can operate with standard components, but the spot size cannot be reduced below physical and Rayleigh limits
Solution Approach 1:
A microsphere is introduced as an intermediary optical element between the objective lens and the substrate. The microsphere has a diameter of about 1/300 or less than the objective lens, enabling it to further condense light and achieve a smaller spot size that overcomes the Rayleigh limit of conventional optical systems.
Solution Approach 2:
The system changes the physical parameters of the optical path by introducing a microsphere with specific size characteristics (diameter about 1/300 or less than the objective lens). This parameter change enables super-resolution light condensation beyond the conventional diffraction limit.
2Measurement precision
If the microsphere diameter is reduced to about 1/300 or less than the objective lens diameter, then the spot size is reduced and inspection precision is improved, but the alignment and positioning difficulty increases
Solution Approach 1:
The system employs dynamic positioning mechanisms to adjust the microsphere's location in the vertical direction. This dynamic adjustment capability allows the system to compensate for alignment difficulties and maintain precise focal points despite the microsphere's small size and sensitivity to positioning.
Solution Approach 2:
The system uses feedback control to detect and adjust the microsphere's position, ensuring accurate alignment with the objective lens and substrate. This feedback mechanism mitigates the alignment difficulty by continuously monitoring and correcting the microsphere's position.
3Manufacturing precision
If additional microspheres are introduced into the optical path, then light condensation is improved and focal precision is enhanced, but the device complexity and manufacturing difficulty increase
Solution Approach 1:
The optical system is segmented into distinct functional components: the objective lens for initial light gathering and one or more microspheres for secondary condensation. This segmentation allows each component to be optimized independently, with the microspheres serving as specialized elements for achieving ultra-fine focal precision.
Solution Approach 2:
The microsphere is positioned within the optical path of the objective lens, creating a nested configuration where the microsphere operates within the broader optical system. This nesting allows the microsphere to leverage the objective lens's light-gathering capability while adding its own condensation function.
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 enhances the reliability of substrate inspection by effectively condensing light onto smaller focal points, overcoming the limitations of existing technologies and improving the precision of semiconductor device fabrication.
Implementation Method 1
at least one microsphere disposed between an upper surface of the stage and the objective lens, the at least one microsphere configured to allow the first light provided from the objective lens to pass therethrough, and to condense the first light on the substrate
Data Source
AI summary
A method for fabricating a semiconductor device is provided. The method includes: loading a substrate on a stage of an apparatus for inspecting the substrate; extracting a first light having a first wavelength from a light by using a light source; acquiring first position information on at least one focal point, formed on the substrate, based on the first wavelength by using a controller, the at least one focal point being a pre-calculated at least one focal point; adjusting a position of at least one from among an objective lens and at least one microsphere in a vertical direction by using the first position information in the controller; condensing the first light, which has passed through the at least one microsphere, on the at least one focal point formed on the substrate; and inspecting the substrate by using the first light condensed on the at least one focal point.