Semiconductor Inspection System Using Secondary Ion Mass Spectrometry
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current inspection systems for semiconductor structures lack the capability to effectively distinguish between different materials and isotopes at the nanoscale, particularly in 2D and 3D structures, and fail to provide high spatial resolution and elemental/chemical information necessary for defect analysis and material characterization.
Innovation Solution
An inspection system utilizing an ion beam source and a secondary ion mass spectrometer to measure ion mass-to-charge ratios with high spatial resolution, enabling the detection of different elements and isotopes, and incorporating a secondary electron imaging optics for detailed analysis of semiconductor structures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional inspection systems are used for semiconductor structures, then basic structural inspection is possible, but the capability to distinguish between different materials and isotopes at nanoscale is lacking
Solution Approach 1:
The patent combines secondary ion mass spectrometry (SIMS) with scanning electron microscopy (SEM) into a single integrated inspection system. The mass spectrometer and electron microscope share common components including the ion beam source, sample stage, and detection systems, enabling simultaneous material composition analysis and structural imaging without requiring separate devices.
Solution Approach 2:
The inspection system performs multiple functions using a unified platform: it conducts secondary ion mass spectrometry for material and isotope identification, secondary electron imaging for structural visualization, and critical dimension measurement. This multi-functionality eliminates the need for multiple separate inspection devices while maintaining nanoscale resolution capabilities.
2Manufacturing precision
If high spatial resolution is achieved with ion beam, then focal diameter can be smaller than 1 nm, but the current beam intensity must be reduced
Solution Approach 1:
The system employs a focused ion beam with diameter smaller than 1 nm to achieve high spatial resolution for localized analysis. By concentrating the ion beam to a very small focal spot, the patent enables precise material characterization at specific locations without requiring high overall beam current, thus maintaining low current operation for high-resolution imaging.
3Loss of information
If mass spectrometer is used to simultaneously measure ion mass to charge ratio, then elemental and chemical information is obtained, but the system complexity increases
Solution Approach 1:
The mass spectrometer is integrated with the electron microscope system, sharing the ion beam source and sample chamber. This merging allows simultaneous acquisition of mass spectral data for elemental/chemical identification and electron images for structural context, comprehensive material characterization without requiring separate standalone mass spectrometry equipment.
4Measurement precision
If secondary ion imaging is performed with high resolution, then detailed material distribution is obtained, but the inspection time increases
Solution Approach 1:
The system performs continuous secondary ion mass spectrometry measurements while maintaining the ion beam in a stable, focused state. By keeping the ion beam continuously active and optimized for secondary ion production, the patent enables high-resolution material distribution mapping without repeated beam setup or adjustment, reducing total inspection time while maintaining precision.
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 system achieves high-resolution secondary ion imaging and mass spectrometry, allowing for precise characterization of semiconductor structures, including defect detection and material distribution analysis, with a focal diameter smaller than 1 nm and lateral space resolution better than 100 nm, enhancing the quality assessment of semiconductor structures during manufacturing.
Implementation Method 1
an ion beam source for space-resolved exposition of the structures to be qualified with an ion beam
Implementation Method 2
a mass spectrometer configured to simultaneously measure an ion mass to charge ratio in a given bandwidth
Data Source
AI summary
An inspection system serves to qualify semiconductor structures. The inspection system has an ion beam source for space-resolved exposition of the structures to be qualified with an ion beam. The inspection system also includes a secondary ion detection device with a mass spectrometer. The mass spectrometer is configured to measure an ion mass to charge ratio in a given bandwidth.