Bulk deposition for tilted mill protection
AssigneeFEI Company
InventorsStacey Stone, Sang Hoon Lee, Jeffrey Blackwood, Michael Schmidt
Life of this patent
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Abstract
To reduce artifacts in a surface exposed by a focused ion beam for viewing, a trench is milled next to the region of interest, and the trench is filled to create a bulkhead. The ion beam is directed through the bulkhead to expose a portion of the region of interest for viewing. The trench is filled, for example, by charged particle beam-induced deposition. The trench is typically milled and filled from the top down, and then the ion beam is angled with respect to the sample surface to expose the region of interest.
Claims20
A method of using a charged particle beam to expose a feature of interest in a sample, including:
- milling a trench adjacent to the feature of interest in a surface of the sample;
- filling the trench with a material using beam-induced deposition;
- directing an ion beam to expose the feature of interest from an angle that requires milling through the deposited material, the angle being an angle between the surface and the ion beam that is less than or equal to 45°;
- and
- observing the exposed feature of interest.
A method of exposing a feature of interest in a sample with a charged particle beam, the sample comprising a first material, the method comprising:
- milling a hole adjacent to the feature of interest in a surface of the sample;
- filling the hole with a second material;
- and
- directing an ion beam from an angle that requires milling through the second material to expose the feature of interest, wherein the angle is an angle between the surface and the ion beam that is less than or equal to 45°.
A system for exposing a feature of interest in a sample, comprising:
- an ion optical column for providing a focused beam of ions;
- an electron optical column for providing a focused beam of electrons;
- a particle detector for detecting secondary particles emitted from the sample;
- and
- a controller communicating to a computer memory, the computer memory storing instructions for:
- milling a hole adjacent to the feature of interest in a surface of the sample;
- filling the hole with a second material using charged particle beam deposition;
- directing an ion beam to expose the feature of interest from an angle that requires milling through the deposited second material, the angle being an angle between the surface and the ion beam that is less than or equal to 10°, wherein milling through the deposited second material comprises performing a glancing angle mill and re-orienting the sample before performing the glancing angle mill;
- and
- imaging the sample using a scanning electron microscope.
Dependencies are inferred from the claim text.