Ion Beam Sample Preparation with Tilting Beam and Datum Shield
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Solution Overview
Problem
Existing ion beam sample preparation methods are inefficient in minimizing handling and processing time, ensuring accurate positioning, and achieving high-quality surface preparation for microscopic observation, particularly in exposing regions of interest without causing damage to delicate samples.
Innovation Solution
The development of an ion beam sample preparation apparatus that allows for repeatable and accurate positioning of samples using a tilting ion beam, enabling multiple tilt angles and sample rotation, which facilitates consistent and desirable surface preparation by integrating the sample with a shield having datum features for precise alignment and secure adhesion, reducing the need for extensive fixturing and minimizing handling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If traditional ion beam sample preparation methods are used, then sample preparation can be performed, but handling time and processing time are excessive and sample damage risk increases
Solution Approach 1:
The patent combines the sample holder and shield into a single integrated assembly with datum features that align precisely with the ion beam apparatus. This merging eliminates separate handling steps for mounting samples to shields, reducing handling time and minimizing opportunities for sample damage while ensuring repeatable positioning.
Solution Approach 2:
The sample is pre-mounted to the shield with datum features engaged before entering the ion beam apparatus. This preliminary positioning action ensures that when the sample enters the preparation chamber, it is already in the correct position, eliminating the need for time-consuming alignment procedures inside the chamber and reducing overall processing time.
2Reliability
If multiple handling steps are used for sample mounting and transfer, then sample preparation can be performed, but the number of handling steps increases sample damage risk
Solution Approach 1:
By integrating the sample mounting and shielding functions into a single pre-assembled unit with integrated datum features, the patent reduces multiple separate handling operations (mounting sample to holder, then holder to shield, then shield to apparatus) into a single handling step, thereby reducing sample damage risk while maintaining operational simplicity.
3Measurement precision
If precise positioning is achieved through complex fixturing, then sample positioning accuracy improves, but device complexity increases
Solution Approach 1:
The patent segments the positioning function into two parts: passive datum features built into the sample holder/shield assembly, and active alignment features in the ion beam apparatus. This segmentation achieves precise positioning through simple geometric mating surfaces rather than complex active fixturing mechanisms, reducing device complexity while maintaining positioning accuracy.
Solution Approach 2:
The datum features on the sample holder and shield are designed to self-align and self-position when engaged. The precision positioning is achieved automatically through the geometric relationship between complementary datum features, eliminating the need for complex external fixturing or manual alignment procedures.
4Productivity
If rapid surface preparation is performed, then productivity increases, but surface quality may compromise
Solution Approach 1:
The patent employs a tilting ion beam that can dynamically adjust its angle of incidence on the sample surface. By varying the tilt angle during preparation, the system can achieve both rapid material removal at optimal angles and precise surface finishing at different angles, maintaining high surface quality while achieving rapid preparation rates.
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 reduces processing time, minimizes sample damage, and ensures high-quality surface preparation, allowing for efficient reprocessing and observation with improved alignment and surface consistency, thereby enhancing the efficiency and reliability of ion beam sample preparation.
Implementation Method 1
The impact of ions on the sample sputters material away from the area of ion impact
Implementation Method 2
the sample surface may be polished by the ion beam to a substantially smooth condition further enhancing observational properties of the sample
Data Source
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AI summary
Disclosed are embodiments of an ion beam sample preparation apparatus and methods for using the embodiments. The apparatus comprises a tilting ion beam irradiating means in a vacuum chamber that may direct ions toward a sample, a shield blocking a portion of the ions directed toward the sample, and a shield retention stage with shield retention means that replaceably and removably holds the shield in a position. Complementary datum features on both shield and shield retention stage enable accurate and repeatable positioning of the sample in the apparatus for sample processing and reprocessing. The tilting ion beam irradiating means may direct ions at the sample from more than one tilt angle. A rotating shield retention stage is also disclosed which works in concert with the tilting ion beam irradiating means to improve the flexibility and efficiency of the apparatus in preparing samples for microscopic observation.