Multi-axis sample preparation stage for in situ FIB milling and STEM imaging

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current sample preparation methods for electron microscope imaging are complex and require extensive handling, which can damage sensitive samples, especially when transitioning between focused ion beam milling and scanning transmission electron microscope analysis, particularly concerning temperature control to prevent ice crystal formation.

Innovation Solution

A multi-axis sample preparation stage with bulk and grid holders that allow for rotational and translational movements in multiple degrees of freedom, enabling in situ sample preparation and imaging without the need for extensive sample handling, incorporating focused ion beam and scanning electron microscope capabilities with temperature control for maintaining critical conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If samples are transferred between FIB milling and STEM imaging platforms, then sample preparation can be performed, but sample damage increases due to extensive handling

Engineering Contradiction:
Improvesample preparation capabilityVSAvoidsample integrity
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent combines FIB milling capability and STEM imaging capability into a single integrated platform. The sample stage can perform both sample preparation operations and imaging operations without requiring physical transfer of the sample between separate instruments, thereby eliminating handling-induced damage while maintaining both preparation and imaging functions.

Inventive Principle:
Principle #5Merging (Combining)

2Ease of manufacture

If multiple sample handling operations are performed, then sample preparation is achieved, but temperature control is compromised leading to ice crystal formation

Engineering Contradiction:
Improvesample preparation capabilityVSAvoidtemperature stability
Core Design Contradiction:
Ease of manufactureVSTemperature

Solution Approach 1:

The integrated platform allows all sample preparation steps including FIB milling, sample mounting, and STEM imaging to be performed within a single temperature-controlled chamber. The sample stage maintains cryogenic temperatures throughout the entire process without requiring samples to be removed or transferred to uncontrolled environments, preventing ice crystal formation.

Inventive Principle:
Principle #5Merging (Combining)

3Ease of manufacture

If extensive sample handling is performed to prepare and transfer samples, then sample preparation is complete, but processing time increases

Engineering Contradiction:
Improvesample preparation capabilityVSAvoidprocessing time
Core Design Contradiction:
Ease of manufactureVSLoss of time

Solution Approach 1:

The integrated sample stage enables continuous processing where FIB milling, sample manipulation, and STEM imaging occur in an uninterrupted sequence within the same chamber. Samples can be prepared and imaged back-to-back without the time losses associated with transferring samples between separate instruments or preparing different samples for different operations.

Inventive Principle:
Principle #20Continuity of useful action

4Adaptability or versatility

If samples are transferred between different platforms, then preparation and imaging can be separated, but chamber venting is required causing further handling

Engineering Contradiction:
Improveoperational flexibilityVSAvoidoperational simplicity
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The patent integrates both FIB milling and STEM imaging capabilities within a single sealed chamber that maintains vacuum conditions throughout all operations. The sample stage can perform preparation and imaging without requiring the chamber to be opened or vented to atmosphere, eliminating the additional handling steps that would otherwise be necessary upon re-vacuuming.

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 allows for precise and complex sample manipulations, reducing sample damage and enabling efficient transfer and imaging without venting the chamber, maintaining sample integrity by allowing temperature-controlled in situ processing, thus enhancing the quality of STEM and TEM imaging.

Implementation Method 1

a bulk sample holder configured to rotate a sample position about a first bulk axis parallel to the direction of the bulk sample holder and also rotate the sample position about a bulk flip axis that is perpendicular to the direction of the bulk sample holder

Methodology Applied
Scientific EffectRotation:

Implementation Method 2

The cutting or milling can be performed by a focused ion beam (FIB) system

Methodology Applied
Scientific EffectFocused ion beam milling: Ion Beam

Implementation Method 3

Microscopic imaging, such as scanning transmission electron microscope (STEM), can require positioning along multiple degrees of freedom

Methodology Applied
Scientific EffectElectron transmission: Electron Beam

Implementation Method 4

manipulating samples for both FIB milling and carving and the later STEM analysis to be performed at specific, critical temperature to prevent ice crystal formation in the sample

Methodology Applied
Scientific EffectCryogenic temperature control: Freezing

Data Source

PatentEP2765591B1Sample preparation stage
Publication Date: 2016.07.13 FEI CO
  • EP2765591B1 patent drawingFigure 1
  • EP2765591B1 patent drawingFigure 2
  • EP2765591B1 patent drawingFigure 3

AI summary

Described is a system and method for in situ sample preparation and imaging. The system includes a multi-axis stage 100 having a bulk stage 110 and a grid stage 150 with various degrees of freedom to allow for sample preparation. In some embodiments, a focused ion beam system is used to prepare a lamella on the bulk stage 110. The lamella can then be transferred to the grid stage 150 from the bulk stage 110 without needing to move the multi-axis stage 100 from the focused ion beam system.