Multi-Type Detection Unit for E-Beam Inspection

Solution Overview

Problem

Current e-beam inspection systems struggle to handle both high resolution and high throughput due to limitations in detection systems that cannot manage a large dynamic range of signal currents from tens of pico-amperes to hundreds of nano-amperes, requiring separate systems for different current ranges and increasing space and costs.

Innovation Solution

A multi-type detection unit with a Wien filter, integrating solid-state detectors and E-T detectors, and using neutral density filters, allows for directing signal electrons to specific sections based on resolution and throughput needs, enabling a single system to handle both low current high resolution and high current high throughput modes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a single e-beam inspection system is designed to handle both large and small beam currents, then the system can perform both high resolution and high throughput inspections, but the detection system becomes overly complex and cannot manage the large dynamic range of signal currents

Engineering Contradiction:

Improvecapability to handle both large and small beam currentsVSAvoiddetection system complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The detection system is divided into multiple detection sections, each optimized for specific current ranges. The system includes a first detection section for small beam currents (high resolution mode) and a second detection section for large beam currents (high throughput mode), allowing each section to be specialized rather than requiring a single complex detector to handle all ranges

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The detection system is designed with multi-functional capability through the Wien filter that can direct signal electrons to different detection sections based on the inspection mode. This universal design allows one detection system to perform multiple functions (handling both small and large currents) without requiring separate dedicated systems

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If separate e-beam systems are used for different current ranges, then each system can be optimized for its specific purpose, but the space and costs increase significantly

Engineering Contradiction:

Improveoptimization for specific current rangesVSAvoidspace requirements

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

Multiple detection sections that would traditionally require separate systems are merged into a single integrated detection unit. The first and second detection sections are combined with a shared Wien filter and signal electron collection system, reducing the total space required while maintaining the optimization benefits of having specialized detection paths for different current ranges

Inventive Principle:

Principle #5Merging (Combining)

3Reliability

If separate e-beam systems are used for different current ranges, then each system can be optimized for its specific purpose, but the costs increase significantly

Engineering Contradiction:

Improveoptimization for specific current rangesVSAvoidcosts

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The detection system is designed with multi-functional capability through the Wien filter that can direct signal electrons to different detection sections based on the inspection mode. This universal design allows one detection system to perform multiple functions (handling both small and large currents) without requiring separate dedicated systems

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

Multiple detection sections that would traditionally require separate systems are merged into a single integrated detection unit. The first and second detection sections are combined with a shared Wien filter and signal electron collection system, reducing the total space required while maintaining the optimization benefits of having specialized detection paths for different current ranges

Inventive Principle:

Principle #5Merging (Combining)

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

This solution enables a single e-beam inspection system to efficiently manage a wide dynamic range of signal currents, improving both resolution and throughput without the need for multiple systems, thus reducing costs and space requirements.

Implementation Method 1

a Wien filter (also known as an E×B charged particle analyzer)

Methodology Applied

Scientific EffectWien filter (E×B charged particle analyzer): Lorentz Force

Implementation Method 2

integrating a solid state detector and an E-T detector into one detection unit to collect signal electrons

Methodology Applied

Scientific EffectSolid state detector detection: Photoelectric Effect

Implementation Method 3

an E-T detector coated with different scintillant material

Methodology Applied

Scientific EffectE-T detector luminescence: Cathodoluminescence

Implementation Method 4

A neutral density filter can be configured to each section of the detection unit to reduce the intensity of received light during imaging

Methodology Applied

Scientific EffectNeutral density filter absorption: Absorption (EM radiation)

Data Source

PatentUS8350213B2Charged particle beam detection unit with multi type detection subunits

Publication Date: 2013.01.08 ASML NETHERLANDS BV

AI summary

A detection unit of a charged particle imaging system includes a multi type detection subunit in the charged particle imaging system, with the assistance of a Wien filter (also known as an E×B charged particle analyzer). The imaging system is suitable for a low beam current, high resolution mode and a high beam current, high throughput mode. The unit can be applied to a scanning electron inspection system as well as to other systems that use a charged particle beam as an observation tool.