Electron Beam Inspection Device Cylindrical Reference Electrode
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional electron beam inspection devices lack the capability to increase the reference voltage in the lens tube, leading to insufficient resolution for detecting defects in ultrafine semiconductor patterns, and are not suitable for high-speed inspection in semiconductor production lines due to large size and high power consumption.
Innovation Solution
An electron beam inspection device with a cylindrical member inside the lens tube, formed by stacking conductive and insulating layers, allows for increased reference voltage without enlarging the lens tube, reducing aberration and power consumption, and includes a secondary electron optical system outside the cylindrical member to maintain high vacuum and adjust the electron beam position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the reference voltage in the lens tube is increased to improve resolution for detecting ultrafine patterns, then the resolution is improved, but the device size and power consumption increase
Solution Approach 1:
The device is divided into two separate systems: a first electron optical system for generating and accelerating the electron beam, and a second electron optical system for collecting and detecting secondary electrons. This segmentation allows each system to operate independently at optimized voltage levels, enabling high resolution without proportionally increasing overall power consumption.
Solution Approach 2:
A high-voltage reference electrode is introduced as an intermediary element within the lens tube. This electrode establishes a high-voltage reference potential that enables precise electron beam control and high-resolution imaging without requiring the entire lens tube structure to be enlarged or operated at equally high power levels.
2Measurement precision
If the reference voltage in the lens tube is increased to improve resolution, then the resolution is improved, but the device size enlarges
Solution Approach 1:
The electron optical system is segmented into two independent subsystems operating at different voltage levels and spatial zones. The first system (electron gun and accelerator) operates at high voltage to generate the primary beam, while the second system (secondary electron collector and detector) operates at lower voltage. This segmentation allows the lens tube to maintain a compact size while achieving high resolution through the high-voltage reference electrode.
Solution Approach 2:
The high-voltage reference electrode introduces a new voltage dimension within the existing lens tube physical space. Rather than enlarging the lens tube to accommodate higher voltage requirements, the invention adds a voltage reference dimension that enables high-resolution operation without increasing the physical volume of the lens tube structure.
3Productivity
If a compact device design is used to reduce size for production line inspection, then productivity is improved, but the resolution may be insufficient for ultrafine patterns
Solution Approach 1:
The inspection device is segmented into two independent electron optical systems that can operate simultaneously and independently. The first system generates and scans the primary electron beam across the sample at high speed, while the second system collects and detects secondary electrons. This segmentation enables both high-speed operation for productivity and high-resolution detection for ultrafine pattern inspection to occur concurrently within the compact device.
Solution Approach 2:
The high-voltage reference electrode acts as an intermediary that enables compact device design to achieve high resolution. By establishing a high-voltage reference potential within the compact lens tube structure, the device can maintain small size for production line integration while simultaneously achieving the resolution necessary for ultrafine pattern detection.
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
Enables high-resolution, high-speed inspection of ultrafine patterns with a compact device, preventing aberration and performance degradation, and allowing for efficient vacuum maintenance and electron beam adjustment.
Implementation Method 1
irradiating the target sample with an electron beam, detecting secondary electrons emitted from the sample
Implementation Method 2
a magnetic field lens and a small-size magnetic field lens are arranged
Implementation Method 3
a high-speed deflector that deflects a secondary beam so that the secondary beam follows the movement of a wafer
Data Source
AI summary
An electron beam inspection device includes: a primary electron optical system that irradiates the surface of a sample with an electron beam; and a secondary electron optical system that gathers secondary electrons emitted from the sample and forms an image on the sensor surface of a detector. An electron image of the surface of the sample is obtained from a signal detected by the detector, and the sample is inspected. A cylindrical member that is formed with conductors stacked as an inner layer and an outer layer, and an insulator stacked as an intermediate layer is provided inside a lens tube into which the secondary electron optical system is incorporated. An electron orbital path is formed inside the cylindrical member, and the members constituting the secondary electron optical system are arranged outside the cylindrical member.