Method of preparing a sample for microstructure diagnostics, and sample for microstructure diagnostics

Patent metadata

Field	Value
Publication number	US-10734193-B2
Application number	US-201615286699-A
Country	US
Kind code	B2
Filing date	Oct 6, 2016
Priority date	Oct 6, 2015
Publication date	Aug 4, 2020
Grant date	Aug 4, 2020

Abstract

A method of preparing a sample for microstructure diagnostics on a sample body by material-ablating processing, and subsequently producing an examination region on the sample portion, the examination region including a target region to be examined, the method including producing a terracing zone including the target region on at least one surface of the sample portion, wherein at least one notch with flanks extending obliquely in relation to the surface is produced next to the target region by material-ablating beam processing to produce the terracing zone, and ablating material from the surface of the sample portion in the region of the terracing zone by an ion beam, which is radiated under grazing incidence onto the surface obliquely to the direction of extent of the notch such that the target region lies behind the notch in the incoming radiation direction of the ion beam and, as a result of the terracing in the region behind the notch, the surface is recessed substantially parallel to the original height of the surface by way of ion beam processing.

First claim

The invention claimed is:

1. A method of preparing a sample for microstructure diagnostics by preparing a sample portion on a sample body by material-ablating processing, and subsequently producing an examination region on the sample portion, the examination region comprising a target region to be examined, the method comprising:
producing a terracing zone comprising the target region on at least one surface of the sample portion, wherein producing the terracing zone comprises:
producing a plurality of notches with flanks extending obliquely in relation to the at least one surface of the sample portion next to the target region by material-ablating beam processing, the plurality of notches extending at a distance from one another and in parallel to one another; and
ablating material from the at least one surface of the sample portion in the target region in the terracing zone by radiating an ion beam under grazing incidence onto the at least one surface obliquely to a direction of an extent of the plurality of notches such that the target region lies behind the plurality of notches based on an incoming radiation direction of the ion beam relative to the plurality of notches such that the at least one surface of the sample portion is recessed substantially parallel to an original height of the at least one surface by ion beam processing resulting in forming a terrace in the terracing zone behind the plurality of notches,
wherein the terracing zone has an area that encompasses the target region and the plurality of notches.

2. The method according to claim 1 , wherein an electron-transparent examination region, in which the target region lies, is produced in the sample portion.

3. The method according to claim 1 , wherein the plurality of notches are introduced into the at least one surface by laser beam processing.

4. The method according to claim 1 , wherein the distance between neighboring notches is matched to a width of the notches such that the distance lies between two times and ten times, a width of a single notch.

5. The method according to claim 1 , wherein the notches are produced such that the distance between immediately adjacent notches is 20 μm to 100 μm.

6. The method according to claim 1 , wherein each notch is produced such that a width at the at least one surface is 10 μm to 50 μm.

7. The method according to claim 1 , wherein at least one notch having a width varying in the direction of extent is produced, and no further notch lies between that notch and the target region.

8. The method according to claim 1 , wherein at least one notch having a non-linear extent with a changing direction of extent is produced, and no further notch lies between that notch and the target region.

9. The method according to claim 1 , wherein the sample portion is processed on both sides, and the plurality of notches are introduced both on a first surface of the sample portion and on an opposite second surface of the sample portion such that respectively one terracing zone arises on both surfaces of the sample portion and in that material in the target region of the terracing zone is subsequently ablated on the first surface and on the second surface by an ion beam under grazing incidence.

10. The method according to claim 1 , wherein a protective layer is applied to the at least one surface prior to the material-ablating beam processing to produce the plurality of notches, and the plurality of notches in the sample portion is subsequently produced through the protective layer and the protective layer is subsequently removed from the surface.

11. The method according to claim 1 , wherein the incoming radiation direction of the ion beam in an azimuthal direction and/or in a vertical direction is varied periodically or aperiodically over an angle of incidence range when ablating the material by the ion beam.

12. The method according to claim 1 , further comprising conducting an in-line thickness determination to determine a thickness of the sample portion in the target region of the terracing zone while ablating material by an ion beam.

13. A sample for microstructure diagnostics obtainable or obtained by the method of claim 1 , comprising:
the sample portion having the examination region comprising the target region to be examined,
wherein at least one notch with flanks extending obliquely in relation to the surface lies next to the examination region on the at least one surface of the sample portion and a surface level on a side of the notch distant from the examination region is higher than the surface level in the examination region.

14. The sample according to claim 13 , wherein the examination region is an electron-transparent region, and a sample thickness on the side of the plurality of notches distant from the electron-transparent region is greater than in the electron-transparent region.

15. The method according to claim 1 , wherein ablating material from the at least one surface of the sample portion in the target region of the terracing zone by radiating an ion beam is performed using a broad ion beam (BIB).

16. The method according to claim 1 , wherein the plurality of notches comprises two, three, four, five or six notches arranged at a distance from one another are produced in the terracing zone.

Assignees

• Fraunhofer Ges Forschung
• Fraunhofer Ges Zur Foeerderung Der Angewandten Forschung E V

Inventors

• Krause Michael
• Schusser Georg
• Höche Thomas
• Busch Richard

Classifications

• H01J37/3053 Primary

  for evaporating or etching · CPC title

• G01N1/32 Primary

  Polishing; Etching · CPC title

• H01J2237/31749

  Focused ion beam · CPC title

• H01J2237/31745

  for preparing specimen to be viewed in microscopes or analyzed in microanalysers · CPC title

• H01J2237/2802

  Transmission microscopes · CPC title