Method for creating S/tem sample and sample structure
AssigneeFEI Company
InventorsJeff Blackwood, Stacey Stone
Life of this patent
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Abstract
An improved method and apparatus for S/TEM sample preparation and analysis. Preferred embodiments of the present invention provide improved methods for TEM sample creation, especially for small geometry (<100 nm thick) TEM lamellae. A novel sample structure and a novel use of a milling pattern allow the creation of S/TEM samples as thin as 50 nm without significant bowing or warping. Preferred embodiments of the present invention provide methods to partially or fully automate TEM sample creation, to make the process of creating and analyzing TEM samples less labor intensive, and to increase throughput and reproducibility of TEM analysis.
Claims25
An method of extracting one or more samples for TEM analysis from a substrate, the method comprising:
- loading the substrate with the sample to be extracted into an ion beam system;
- locating a first sample site on the substrate surface;
- imaging the sample site;
- identifying at least one desired first fiducial location for said first sample site;
- milling a combination of at least one high precision fiducial mark and one low precision fiducial mark at the desired first fiducial locations;
- determining the edge positions for the desired sample with respect to said fiducial marks;
- automatically milling the substrate surface on either side of the desired sample location leaving a thin layer of material;
- and
- extracting the sample.
A method of preparing two or more samples for TEM analysis for extraction from a substrate, the method comprising:
- locating a first sample site on the substrate surface;
- imaging the first sample site;
- identifying one or more desired fiducial locations for said first sample site;
- creating at least one fiducial mark for said first sample site;
- locating a second sample site on the substrate surface;
- using pattern recognition to identify at least one second fiducial location for said second sample site so that the spatial relationships between said second fiducial location and said second sample site will be identical to the spatial relationships between said first fiducial location and said first sample site;
- automatically creating a fiducial mark at the identified at least one second fiducial location;
- determining the edge positions for the desired samples to be extracted with respect to said fiducial marks;
- milling the wafer surface on either side of the desired sample locations leaving a thin layer of material containing the samples to be extracted;
- separating the samples from the substrate;
- and
- extracting the samples.
Dependencies are inferred from the claim text.