Charged Particle Beam Device Light Irradiation Contrast
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Solution Overview
Problem
In semiconductor device manufacturing, it is challenging to obtain clear contrasts in secondary electron images for thin insulating films using low acceleration scanning electron microscopes, making it difficult to inspect and measure film thickness and defects accurately due to similar compositions of organic materials and silicon-based semiconductor materials.
Innovation Solution
A charged particle beam device that irradiates a sample with light in addition to the electron beam, altering the signal amount of secondary charged particles to enhance contrast and allow for clear identification of material and shape, even for thin film thicknesses, by controlling light parameters such as wavelength and intensity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a low acceleration electron beam is used to obtain surface information, then shallow penetration depth and surface-rich images are achieved, but image contrast deteriorates for materials with similar compositions
Solution Approach 1:
The patent introduces light as an intermediary substance that mediates between the electron beam and the sample. The light irradiates the sample surface and modifies the secondary electron emission characteristics, creating contrast enhancement without changing the fundamental low-voltage electron beam imaging mechanism. This intermediary approach allows maintaining shallow penetration depth while improving material differentiation capability.
Solution Approach 2:
The patent changes the physical state of the sample surface by irradiating it with light, which alters the secondary electron emission parameters. By controlling light intensity and wavelength, the emission characteristics of secondary electrons are modified, creating detectable contrast differences between materials with similar compositions while maintaining the low acceleration voltage regime.
2Productivity
If the insulating film thickness is reduced to increase implementation density, then device integration is improved, but the contrast between surface insulating film and lower layer decreases
Solution Approach 1:
Light serves as an intermediary that enhances the visibility of thin insulating films by modifying secondary electron emission. Even when the film thickness is reduced for higher density, the light irradiation creates sufficient contrast between the film and substrate by altering electron emission characteristics, enabling accurate thickness evaluation and defect detection at reduced film dimensions.
Solution Approach 2:
By changing the irradiation parameters (light intensity, wavelength, duration), the patent optimizes the contrast enhancement effect for thin films. This parameter control allows maintaining measurement precision for film thickness evaluation even as film dimensions are reduced to increase device implementation density.
3Ease of operation
If organic resist materials and silicon-based semiconductor materials have similar compositions, then material compatibility is achieved, but secondary electron emission difference decreases
Solution Approach 1:
Light acts as an intermediary that reveals subtle differences in secondary electron emission between organic resist materials and silicon-based semiconductor materials. By irradiating the sample with light, the patent enhances the emission contrast between these similarly-composed materials, enabling clear differentiation while maintaining the benefits of low-voltage electron beam imaging.
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 increases the difference in secondary electron signals between film-present and film-absent areas, improving the accuracy of film thickness estimation and defect detection, especially for thinner insulating films, thereby enhancing the visibility of ultrafine patterns and semiconductor device quality inspection.
Implementation Method 1
changes a signal amount of secondary charged particles between when light is applied and when the light is not applied by irradiating a sample with the light
Data Source
AI summary
A charged particle beam device according to the present invention changes a signal amount of emitted charged particles by irradiating the sample with light due to irradiation under a plurality of light irradiation conditions, and determines at least any one of a material of the sample or a shape of the sample according to the changed signal amount.