Ion Milling Stage Alignment for Reproducible Tilted Processing
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Solution Overview
Problem
Existing ion milling devices face challenges in maintaining reproducibility of processed shapes due to deviations in the alignment between the ion beam center and the sample stage rotation center, especially when samples are tilted at large angles, leading to inconsistencies in processing results.
Innovation Solution
The ion milling device incorporates a first finder to align the sample surface to an eucentric position on the tilt axis and a second finder to ensure the processing target remains stationary, using optical systems to adjust the three-axis drive stage for precise alignment, thereby maintaining the ion beam center perpendicular to the tilt axis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the ion beam center and rotation center are precisely aligned using an ion source position adjustment mechanism, then the reproducibility of processed shapes is improved, but the device complexity increases and the alignment requires frequent manual adjustment
Solution Approach 1:
The system performs self-alignment by automatically detecting the rotation center position through image processing of the sample surface and adjusting the ion beam position accordingly, eliminating the need for complex manual alignment mechanisms and reducing operational complexity
Solution Approach 2:
The patent replaces manual mechanical alignment mechanisms with an automated optical detection and image processing system that uses a camera to capture sample surface images, processes them computationally to determine the rotation center, and automatically adjusts the ion beam position based on the calculated offset
2Manufacturing precision
If the ion beam center and rotation center are aligned, then processing reproducibility is improved, but the ease of operation deteriorates due to the need for frequent manual realignment during sample replacement
Solution Approach 1:
The system automatically performs alignment detection and adjustment for each sample without requiring manual intervention, making the operation as convenient as simply placing the sample on the stage while maintaining high reproducibility through automated realignment
Solution Approach 2:
The system performs preliminary alignment detection and correction automatically upon sample placement, so that by the time processing begins, the ion beam is already correctly positioned relative to the rotation center, eliminating the need for operators to perform alignment adjustments
3Manufacturing precision
If real-time control of processed shape is attempted during high-rate ion milling, then shape precision may be improved, but the productivity decreases due to the extremely difficult control requirements
Solution Approach 1:
The system performs preliminary alignment detection and correction using image processing before and during the high-rate milling process, establishing the correct ion beam position in advance and maintaining it through automated adjustments, thereby enabling high productivity without sacrificing shape precision
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 configuration enhances the reproducibility of processed shapes by ensuring accurate and consistent alignment, even when samples are tilted, thereby improving the precision and reliability of ion milling processes.
Implementation Method 1
an optical system of the first finder is disposed on the sample stage such that an optical axis of the optical system coincides with the tilt axis
Implementation Method 2
When atoms on a sample surface are ejected due to a sputtering phenomenon, the sample surface can be polished without stress or an internal structure of the sample can be exposed
Data Source
AI summary
An ion milling device includes: a sample chamber (109); a sample stage (102) tiltable about a tilt axis (T) and configured to allow a sample (120) to be placed thereon via a rotation stage (103) rotating about a rotation axis (R) and a three-axis drive stage (104) that can be driven in three axial directions perpendicular to one another; an ion source (101) configured to emit an unfocused ion beam to the sample and attached to the sample chamber such that an ion beam center (B) of the ion beam is perpendicular to the tilt axis (T); and a first finder (105). An optical system of the first finder is disposed on the sample stage such that an optical axis of the optical system coincides with the tilt axis (T).