FIB Spot Hole Shape Correction for Wide Field Uniformity
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Solution Overview
Problem
In micro-electro-mechanical-systems (MEMS) manufacturing using focused ion beam (FIB) apparatus, distortion of the ion beam outside the center of the beam axis leads to non-uniform processing shapes, requiring repeated stage movement and position adjustments, thereby reducing manufacturing throughput due to increased processing time.
Innovation Solution
A method involving an FIB processing apparatus with an irradiation unit, shape measuring unit, and control unit that measures spot hole shapes in a first region, sets scan conditions or forming masks for each field-of-view point, and applies these conditions to a second region to minimize beam distortion and non-uniformity across a wide field-of-view.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If dynamic focus is used to suppress beam distortion, then processing shape uniformity is improved within a certain range from the center, but the effective processing range remains limited and requires repeated stage movements
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting focus and stigmatic focus parameters based on the beam irradiation position. Correction values for dynamic focal correction and dynamic astigmatic correction are calculated and applied to compensate for beam distortion at different positions across the wide field-of-view, thereby maintaining processing shape uniformity without requiring repeated stage movements
Solution Approach 2:
The patent implements preliminary action by pre-calculating correction values for dynamic focal correction and dynamic astigmatic correction at each position in the field-of-view before actual processing. These correction values are stored and applied during beam irradiation to proactively compensate for expected beam distortion, enabling uniform processing across a wide range in a single field-of-view
2Productivity
If the processing range is extended to a wide field-of-view, then manufacturing efficiency is improved, but beam distortion increases causing non-uniform processing shapes
Solution Approach 1:
The patent uses parameter changes by dynamically adjusting focus and stigmatic focus parameters according to the beam irradiation position across the wide field-of-view. Correction values are calculated to compensate for position-dependent beam distortion, enabling both wide processing range and uniform processing shapes to be achieved simultaneously
Solution Approach 2:
The patent applies local quality by providing position-specific correction values for focus and stigmatic focus at each point in the field-of-view. Each position receives tailored correction parameters based on its local distortion characteristics, allowing uniform processing quality across the entire wide field-of-view
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 reduces non-uniformity of processing shapes over a wide range, enhancing manufacturing efficiency by allowing for more precise and uniform processing without the need for frequent stage movements, thus improving throughput.
Implementation Method 1
an irradiation unit that irradiates a sample with a charged particle beam
Data Source
AI summary
The invention is to reduce non-uniformity of a processing shape over a wide range of a single field-of-view.The invention is directed to a method of processing micro electro mechanical systems with a first step and a second step in a processing apparatus including an irradiation unit that irradiates a sample with a charged particle beam, a shape measuring unit that measures a shape of the sample, and a control unit. In the first step, the irradiation unit irradiates a plurality of single field-of-view points with the charged particle beam in a first region of the sample, the shape measuring unit measures the shape of a spot hole formed in the first region of the sample, and the control unit sets, based on measurement results of the shape of the spot hole, a scan condition of the charged particle beam or a forming mask of the charged particle beam at each of the single field-of-view points. In the second step, the irradiation unit irradiates, based on the scan condition or the forming mask set in the first step, a second region of the sample with the charged particle beam.