Semiconductor Failure Analysis Using Solid Immersion Lens
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Solution Overview
Problem
Current semiconductor failure analysis devices lack the necessary resolution to effectively analyze minute regions within semiconductor devices.
Innovation Solution
A semiconductor failure analysis device that applies a stimulation signal and uses irradiation light with a center wavelength of 880 nm to 980 nm, combined with a solid immersion lens made of gallium arsenide, to improve resolution by increasing numerical aperture and reducing spot diameter, allowing for identification of failure portions, heat sources, and operating frequencies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional light sources and optical systems are used, then the device complexity is low, but the measurement precision is insufficient for analyzing minute regions
Solution Approach 1:
The patent changes the wavelength parameter of the light source to 880-980 nm range and selects gallium arsenide material for the solid immersion lens, which has high transparency in this wavelength range. This parameter change enables both high resolution and sufficient light transmission through the semiconductor substrate without requiring substrate thinning.
Solution Approach 2:
The patent replaces mechanical substrate thinning processes with an optical approach using a solid immersion lens. Instead of physically modifying the substrate to improve light transmission, the solution uses optical elements (solid immersion lens with high refractive index) to achieve the same effect while maintaining substrate integrity and simplifying the overall process.
2Illumination intensity
If substrate thinning is performed to improve light transmission, then the light intensity increases, but the manufacturing complexity and handling difficulty increase
Solution Approach 1:
The patent replaces mechanical substrate thinning with an optical solution using a solid immersion lens. The lens concentrates light at the semiconductor surface, achieving high light intensity without physically modifying the substrate. This eliminates complex thinning processes and maintains substrate integrity for easier handling.
Solution Approach 2:
The solid immersion lens acts as an intermediary element between the light source and the semiconductor device. It focuses and concentrates the light at the semiconductor surface, providing high light intensity for detection while avoiding the need to modify the semiconductor substrate itself.
3Quantity of substance
If conventional light wavelengths are used, then the optical system is simple, but the light transmission through the semiconductor substrate is insufficient
Solution Approach 1:
The patent changes the wavelength parameter to 880-980 nm, which falls in the near-infrared range where silicon and other semiconductor materials have high transmission characteristics. This wavelength selection, combined with the solid immersion lens, achieves sufficient light transmission through the substrate without requiring additional optical components or substrate modification.
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
The device achieves improved resolution and light intensity for identifying failure portions within semiconductor devices, reducing the need for substrate thinning and simplifying analysis processes, while maintaining handling ease of semiconductor wafers.
Implementation Method 1
the refractive index of the solid immersion lens formed of gallium arsenide is higher than the refractive index of air. Therefore, it is possible to increase a numerical aperture (NA). As a result, it becomes possible to reduce a spot diameter of the irradiation light
Implementation Method 2
The irradiation light having a center wavelength of 880 nm or more and 980 nm or less is sufficiently transmitted through the semiconductor device which is the analysis target
Implementation Method 3
a light detection unit configured to receive reflected light generated by the irradiation light being reflected by the semiconductor device
Data Source
AI summary
The semiconductor failure analysis device 1 includes: a tester 2 configured to apply a stimulation signal to a semiconductor device 100; a light source 3 configured to generate irradiation light L1 with which the semiconductor device 100 is irradiated; a solid immersion lens 4 disposed on an optical path of the irradiation light L1; a light detection unit 5 configured to receive reflected light L2 and to output a detection signal according to the reflected light L2; an optical system 6 disposed between the light source 3 and the solid immersion lens 4 to emit the irradiation light L1 to the semiconductor device 100 via the solid immersion lens 4 and disposed between the solid immersion lens 4 and the light detection unit 5 to emit the reflected light L2 received via the solid immersion lens 4 to the light detection unit 5; and a computer 7 configured to obtain information on a failure portion of the semiconductor device 100 using the detection signal. The light source 3 emits the irradiation light L1 having a center wavelength of 880 nm or more and 980 nm or less. The solid immersion lens 4 is formed of GaAs.