Enhancement Grating Amplifies tSAXS Scattering Intensity

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Solution Overview

Problem

Current transmission small-angle X-ray scattering (tSAXS) techniques face challenges in achieving sufficient scattering intensity for nanoscale feature measurements, particularly in the semiconductor industry, due to limitations in X-ray intensity and flux from laboratory sources, which hinder throughput and practical application in high-volume manufacturing.

Innovation Solution

An apparatus is introduced that includes an enhancement grating object positioned within the longitudinal coherence length of an incident X-ray beam from a target object, with a placement mechanism allowing nanometer precision alignment, to amplify scattering intensity by interacting with the X-ray beam and enhancing the detectable signal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional tSAXS measurement is used with laboratory X-ray sources, then the measurement can be performed with available equipment, but the scattering intensity is insufficient leading to long measurement times and low throughput

Engineering Contradiction:
Improvescattering intensityVSAvoidmeasurement throughput
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

An enhancement grating is introduced as an intermediary component between the target object and the detector. This grating modulates the X-ray beam to create interference patterns that amplify the scattering signal from the target structure, thereby increasing detectable intensity without requiring higher source flux

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system changes the measurement parameters by introducing a periodic modulation structure (enhancement grating) that transforms the scattering signal into a modulated interference pattern. This parameter transformation enhances the detectability of weak scattering signals from nanoscale features

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If longer measurement times are used to accumulate sufficient scattering signal, then measurement precision improves, but productivity and throughput decrease

Engineering Contradiction:
Improvesignal qualityVSAvoidmeasurement time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The enhancement grating acts as a signal amplifier that increases the scattering intensity detected from the target object. By modulating the X-ray beam through the enhancement grating, the system achieves better signal quality in reduced measurement time

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The enhancement grating is pre-positioned within the longitudinal coherence length of the incident X-ray beam before measurement begins. This preliminary arrangement ensures that the beam is properly conditioned to produce enhanced scattering signals from the target object

Inventive Principle:
Principle #10Preliminary action

3Ease of operation

If the enhancement grating is positioned at greater distance from the target object, then alignment complexity decreases, but the scattering intensity enhancement effect diminishes

Engineering Contradiction:
Improvealignment complexityVSAvoidscattering intensity enhancement
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The system operates within the longitudinal coherence length parameter regime, which provides a specific distance range where the enhancement effect is maximized. By controlling the positioning within this coherence length, the system achieves optimal enhancement while maintaining practical alignment requirements

Inventive Principle:
Principle #35Parameter changes

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 approach significantly enhances the scattering intensity from the target object, reducing measurement time and improving signal quality, thereby facilitating more efficient critical dimension characterization and increasing the practicality of tSAXS for in-line IC metrology applications.

Implementation Method 1

an enhancement grating object positioned within a longitudinal coherence length of an incident X-ray from a target object

Methodology Applied
Scientific EffectDiffraction: Diffraction

Implementation Method 2

amplify scattering intensity by interacting with the X-ray beam

Methodology Applied
Scientific EffectInterference: Interference

Data Source

PatentEP2863213B1Apparatus for amplifying intensity during transmission small angle X-ray scattering measurements
Publication Date: 2019.11.27 IND TECH RES INST
  • EP2863213B1 patent drawingFigure 1~2
  • EP2863213B1 patent drawingFigure 3a
  • EP2863213B1 patent drawingFigure 3b~3c

AI summary

The disclosure provides an apparatus for amplifying scattering intensity during tSAXS measurements. The apparatus includes an enhancement grating object (14) and a placement mechanism. The enhancement grating object is positioned within a longitudinal coherence length of an incident X-ray from a target object (12). The placement mechanism is capable of placing the enhancement grating object with nanometer precision with respect to the target object in both a lateral and a longitudinal directions.