Rotatable Probe for TEM Plan View Sample Reorientation
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Solution Overview
Problem
Current methods for preparing plan view samples for TEM or STEM analysis are cumbersome, particularly when attempting ex-situ liftout, as they require expensive flip stages and cannot easily reorient samples from a horizontal to a vertical orientation without removing the TEM grid from the vacuum chamber.
Innovation Solution
A method and apparatus that utilize an ion beam system with a rotatable probe to reorient a plan view sample from a horizontal to a vertical orientation, allowing for attachment and thinning without a flip stage, by milling the sample, attaching a probe, rotating the probe to change the sample's orientation, and thinning the sample using the ion beam.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a plan view sample is prepared using conventional methods with a flip stage, then the sample can be reoriented from horizontal to vertical, but the process becomes complex and expensive requiring specialized equipment
Solution Approach 1:
Instead of flipping the sample stage to reorient the sample, the invention inverts the approach by rotating the probe holder that holds the sample. The probe holder is rotated about its shaft axis, which causes the sample to rotate from horizontal to vertical orientation while the stage remains stationary. This eliminates the need for a flip stage.
Solution Approach 2:
The probe holder acts as an intermediary between the stationary stage and the sample. By rotating the probe holder about its shaft axis, the sample orientation is changed without moving the stage. The probe holder's rotation serves as the mediating action that transforms the sample orientation from horizontal to vertical.
2Ease of operation
If the TEM grid is removed from the vacuum chamber to reorient the sample, then the sample orientation can be changed, but the preparation time increases significantly
Solution Approach 1:
The probe is attached to the sample at a non-normal angle (e.g., 45 degrees) to the stage plane before sample preparation. This preliminary angular positioning enables subsequent rotation of the probe holder to achieve vertical sample orientation without requiring chamber evacuation or grid removal. The non-normal probe attachment angle is prepared in advance to facilitate the rotation operation.
Solution Approach 2:
The probe holder is designed to be rotatable about its shaft axis, introducing dynamic capability to the otherwise static sample mounting system. This rotation allows the sample to transition from horizontal to vertical orientation while remaining in the chamber, eliminating the need for time-consuming chamber evacuation and reinstallation procedures.
3Adaptability or versatility
If ex-situ liftout is attempted with conventional methods, then the sample can be extracted, but the process cannot easily reorient samples without specialized equipment
Solution Approach 1:
The probe holder rotation mechanism serves multiple functions: it enables both in-situ sample orientation change during FIB preparation and facilitates ex-situ liftout by allowing the sample to be extracted in vertical orientation. This single rotational degree of freedom provides universal capability for both preparation modes without requiring specialized flip stages or other complex equipment.
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 efficient preparation and mounting of plan view samples for TEM or STEM analysis without the need for flip stages, allowing for ex-situ liftout and maintaining the sample in a suitable orientation for electron beam transmission without chamber reorientation.
Implementation Method 1
A sample is milled from a first work piece using an ion beam so that the sample is substantially free from the first work piece
Implementation Method 2
The sample is thinned using the ion beam to form a lamella, the lamella being oriented in the lamella plane
Data Source
AI summary
A method and apparatus for altering the orientation of a charged particle beam sample is presented. Embodiments of the method includes providing a first work piece on a sample stage having a sample stage plane, the first work piece including a lamella plane in a first orientation. A sample is milled from the first work piece using an ion beam so that the sample is substantially free from the first work piece. A probe is attached to the sample, the probe including a shaft having a shaft axis, the shaft axis oriented at a shaft angle in relation to the sample stage plane, the shaft angle being non-normal to the sample stage plane. The probe is rotated about the shaft axis through a rotational angle so that the lamella plane is in a second orientation. The sample is attached to or placed on the sample on either the first work piece, the first work piece being the work piece from which the sample was milled, or on a second work piece, the second work piece being a work piece from which the sample was not milled. The sample is thinned using the ion beam to form a lamella, the lamella being oriented in the lamella plane.