2-D Beam Profile Reflectometry for Thick Films and HAR Structures
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Solution Overview
Problem
Current semiconductor metrology systems face limitations in measuring thick films, high aspect ratio structures, and large pitch targets due to restricted angle of incidence ranges, limited measurement diversity, and slow throughput, particularly in 2-D beam profile reflectometry systems.
Innovation Solution
A 2-D beam profile reflectometry system is designed with a light source emitting light at various wavelengths and angles, combined with a polarization assembly and main objective to focus and collect light from targets, utilizing a processor to generate measurements based on polarization states, wavelengths, and angles of incidence, enabling enhanced measurement diversity and speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If 1-D BPR systems are used to sample x-slice and y-slice of the pupil, then device complexity is reduced, but measurement diversity for HAR structures is insufficient
Solution Approach 1:
The system evolves from 1-D to 2-D BPR by capturing the complete pupil rather than just slices. This enables simultaneous acquisition of reflectometry data across multiple angles of incidence and azimuths, providing the measurement diversity required for high aspect ratio structures while maintaining a single integrated optical path that does not substantially increase device complexity
2Adaptability or versatility
If 2-D BPR systems capture the full pupil, then measurement diversity is improved, but the field of view is limited which reduces light collection from HAR structures
Solution Approach 1:
The patent implements 2-D BPR that captures the full pupil, enabling simultaneous measurement across multiple angles of incidence and azimuths. This dimensional expansion in angular space provides comprehensive measurement diversity for thick films and high aspect ratio structures, with the field of view optimized for the specific application rather than being a limiting factor
3Adaptability or versatility
If SE systems move the stage or optics to sample one AOI at a time, then AOI range is improved, but throughput becomes too slow for high-volume production
Solution Approach 1:
The patent combines multiple measurement capabilities into a single 2-D BPR system that captures the full pupil simultaneously. By merging angular diversity (multiple AOIs and azimuths) and spectral information into one measurement, the system achieves comprehensive characterization without the need to mechanically scan or move components, thereby maintaining high throughput for high-volume production
4Device complexity
If existing metrology systems use limited wavelengths, polarization states, or angles, then device complexity is reduced, but measurement sensitivity and diversity for 3D structures are insufficient
Solution Approach 1:
The patent implements 2-D BPR that captures the full pupil, enabling simultaneous acquisition of reflectometry data across multiple angles of incidence and azimuths. This dimensional expansion provides comprehensive angular and spectral information necessary for sensitive characterization of 3D structures, including thick films and high aspect ratio structures, with enhanced measurement diversity
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 higher measurement diversity, accuracy, precision, and faster results for thick films and high aspect ratio structures by capturing data over a wide range of angles and combining BPR data with spectroscopic ellipsometry and reflectometry data, providing a data cube for process optimization.
Implementation Method 1
a light source configured to emit light along an illumination path at one or more wavelengths, one or more angles of incidence (AOI), and one or more azimuths
Implementation Method 2
a main objective configured to focus the light in the one or more polarization states onto a target and collect the light reflected from the target
Implementation Method 3
The target may be configured to reflect the light along a collection path
Implementation Method 4
a polarization assembly disposed in the illumination path configured to produce one or more polarization states of the light
Implementation Method 5
an analyzer assembly disposed in the collection path configured to analyze one or more polarization states of the light reflected from the target
Implementation Method 6
a detector configured to detect the light reflected from the target and generate an output signal based on the detected light
Data Source
AI summary
The system includes a light source configured to emit light at one or more wavelengths, one or more angles of incidence (AOI), and one or more azimuths; a polarization assembly configured to produce one or more polarization states of the light; a main objective configured to focus the light in the one or more polarization states onto a target that reflects the light; an analyzer assembly configured to analyze one or more polarization states of the light reflected from the target; a detector configured to detect the light reflected from the target and generate an output signal based on the detected light; and a processor configured to generate a measurement of the target based on the output signal produced at the one or more polarization states, the one or more wavelengths, the one or more AOIs, and the one or more azimuths.