Spectroscopic Measuring Apparatus Microlens Spot Size Control
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Solution Overview
Problem
Conventional spectroscopic measuring apparatuses face limitations in achieving high resolution and accuracy for measuring microstructures due to constraints on spot size and signal-to-noise ratio, particularly in semiconductor device analysis, where spot sizes of 1 μm or less are difficult to achieve without compromising intensity and sensitivity.
Innovation Solution
The proposed spectroscopic measuring apparatus incorporates a microlens, such as a micro-sphere lens, to enhance magnification and optical resolution, combined with precise control of the object lens and optical fiber positions to achieve a spot size below the diffraction limit, allowing for high-resolution spectral signal acquisition in small semiconductor pattern regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional spectroscopic measuring apparatuses are used, then measurement can be performed, but spot size cannot be reduced to 1 μm or less without compromising intensity and sensitivity
Solution Approach 1:
The optical system is segmented into multiple functional components: object lens for initial focusing, microlens for spot size reduction, and imaging lens for signal collection. This segmentation allows each component to optimize for its specific function, enabling spot size reduction to 1 μm or less while maintaining signal intensity through the coordinated action of all segments
Solution Approach 2:
The microlens acts as an intermediary element between the object lens and the measurement target. It receives light from the object lens and transforms it into a tightly focused spot on the sample, then transmits the reflected light to the imaging lens. This intermediary enables spot size reduction without direct compromise to the overall signal intensity by mediating the optical path efficiently
2Measurement precision
If spot size is reduced to achieve high resolution, then measurement accuracy improves, but signal-to-noise ratio deteriorates
Solution Approach 1:
The system merges the functions of multiple optical components (object lens, microlens, imaging lens) into a unified optical path that simultaneously achieves spot size reduction and signal collection. The combined action of these lenses creates a system where high resolution and good signal-to-noise ratio coexist, as the imaging lens compensates for the reduced light intensity from the small spot
Solution Approach 2:
The system changes optical parameters through the microlens configuration, specifically transforming the light cone angles and focal properties. By adjusting the microlens position and focal length parameters, the system achieves optimal balance between spot size (affecting resolution) and collected light intensity (affecting signal-to-noise ratio), enabling both high measurement accuracy and reliability
3Manufacturing precision
If microlens is added to enhance magnification, then optical resolution improves, but device complexity increases
Solution Approach 1:
The microlens serves multiple functions simultaneously: it acts as a focusing element to reduce spot size, a magnifying element to enhance optical resolution, and a light guiding element to maintain signal intensity. This multi-functionality justifies the added complexity by delivering multiple performance benefits from a single component addition
Solution Approach 2:
The microlens utilizes spherical or aspherical curvature to achieve high magnification and resolution in a compact form factor. The curved optical surfaces enable efficient light focusing and imaging without requiring complex mechanical structures, thereby improving optical resolution while minimizing the increase in device complexity
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 enables accurate and non-destructive measurement of microstructures, improving imaging magnification and signal sensitivity, thereby effectively managing semiconductor manufacturing yields and enabling precise measurements in narrow areas like DRAM or VNAND cells.
Implementation Method 1
a microlens (400), disposed between the object lens (200) and the stage (950)
Implementation Method 2
an object lens (200) configured to allow light from the first light source (100) to be incident on a stage (950) configured to support a measurement object (2000)
Implementation Method 3
an imaging lens (300) configured to image light reflected from the measurement object (2000)
Implementation Method 4
a spectrometer (600) disposed at an output terminal of the optical fiber (500)
Data Source
AI summary
A spectroscopic measuring apparatus and method are provided. The apparatus includes a first light source, object, microlens, and imaging lenses, an optical fiber, a spectrometer and a position controller. The object lens to allows light from the first light source to be incident on a stage configured to support a measurement object. The microlens is disposed between the object lens and the stage. The imaging lens images light reflected from the measurement object. The optical fiber has an input terminal disposed on a first image plane of the imaging lens. The spectrometer is disposed at an output terminal of the optical fiber. The position controller controls positions of the object lens, the microlens, and the optical fiber, and adjusts the position of the object lens so that a focus of the object lens is positioned at a virtual image position of a virtual image generated by the microlens.