Multi-Beam Inspection Apparatus with Movable Aperture Plate
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Solution Overview
Problem
Conventional multi-beam inspection systems suffer from low inspection accuracy and resolution due to crosstalk between adjacent electron beams, requiring samples to be transferred to high-resolution single-beam tools for closer inspection, and newer systems with dual-mode support have lower max resolution than conventional single-beam tools.
Innovation Solution
A multi-beam inspection apparatus with an adaptive control mechanism that eliminates off-axis electron beams near the electron beam source, allowing the apparatus to operate in both multi-beam and single-beam modes with improved resolution by using a movable aperture plate to block or allow specific electron beamlets, and incorporating multiple electron detection devices for enhanced defect detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a multi-beam inspection system is used, then inspection throughput is improved, but inspection accuracy and resolution deteriorate due to crosstalk between adjacent electron beams
Solution Approach 1:
The system dynamically switches between multi-beam mode (for high throughput inspection) and single-beam mode (for high resolution review) using a movable aperture plate that can reposition to either block off-axis beams or allow them to pass, enabling the inspection tool to adapt its beam configuration based on the specific inspection task at hand
2Measurement precision
If a conventional single-beam tool is used for high-resolution inspection, then measurement precision is improved, but productivity deteriorates due to lower inspection throughput
Solution Approach 1:
The patent merges the capabilities of both multi-beam and single-beam inspection systems into one unified apparatus by incorporating a movable aperture plate that can configure the beam system to operate in either multi-beam mode (high throughput) or single-beam mode (high resolution), eliminating the need for separate tools and sample transfers
3Adaptability or versatility
If dual-mode support is added to multi-beam systems, then adaptability is improved, but manufacturing precision deteriorates due to lower max resolution compared to conventional single-beam tools
Solution Approach 1:
The movable aperture plate provides dynamic reconfiguration capability, allowing the system to switch between multi-beam and single-beam modes. When single-beam mode is activated for review inspections, the aperture plate positions to block off-axis beams, enabling the system to achieve conventional single-beam resolution levels while maintaining the flexibility of dual-mode operation
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 solution enables high-throughput inspection with improved resolution in single-beam mode, potentially eliminating the need for separate single-beam review tools and increasing overall inspection throughput by performing both high-throughput and high-resolution inspections within a single tool.
Implementation Method 1
a beam of primary electrons having a relatively high energy is decelerated to land on a sample at a relatively low landing energy and is focused to form a probe spot thereon. Due to this focused probe spot of primary electrons, secondary electrons will be generated from the surface.
Implementation Method 2
a first aperture plate configured to form a plurality of charged particle beamlets from the charged particle beam, and a second aperture plate, movable between a first position and a second position
Data Source
AI summary
A multi-beam inspection apparatus supporting a plurality of operation modes is disclosed. The charged particle beam apparatus for inspecting a sample supporting a plurality of operation modes comprises a charged particle beam source configured to emit a charged particle beam along a primary optical axis, a movable aperture plate, movable between a first position and a second position, and a controller having circuitry and configured to change the configuration of the apparatus to switch between a first mode and a second mode. In the first mode, the movable aperture plate is positioned in the first position and is configured to allow a first charged particle beamlet derived from the charged particle beam to pass through. In the second mode, the movable aperture plate is positioned in the second position and is configured to allow the first charged particle beamlet and a second charged particle beamlet to pass through.