Method for producing a probe suitable for scanning probe microscopy

Patent metadata

Field	Value
Publication number	US-11035880-B2
Application number	US-202016802944-A
Country	US
Kind code	B2
Filing date	Feb 27, 2020
Priority date	Mar 1, 2019
Publication date	Jun 15, 2021
Grant date	Jun 15, 2021

Abstract

Example embodiments relate to methods for producing a probe suitable for scanning probe microscopy. One embodiment includes a method for producing a probe tip suitable for scanning probe microscopy. The method includes producing a probe tip body that includes at least an outer layer of a probe material. The method also includes, during the production of the probe tip body or after the production, forming a mask layer on the outer layer of probe material. Further, the method includes subjecting the probe tip body to a plasma etch procedure. The mask layer acts as an etch mask for the plasma etch procedure. The plasma etch procedure and the etch mask are configured to produce one or more tip portions formed of the probe material. The one or more tip portions are smaller and more pointed than the probe tip body prior to the plasma etch procedure.

First claim

What is claimed is:

1. A method for producing a probe tip suitable for scanning probe microscopy (SPM), comprising:
producing a probe tip body comprising at least an outer layer of a probe material, the probe tip body comprising an apex area;
during the production of the probe tip body or after the production, forming a mask layer on the outer layer of probe material; and
subjecting the probe tip body to a plasma etch procedure, wherein the mask layer acts as an etch mask for the plasma etch procedure, wherein the plasma etch procedure and the etch mask are configured to produce one or more tip portions formed of the probe material, and wherein each one of the one or more tip portions is smaller and has a higher aspect ratio than the apex area of the probe tip body prior to the plasma etch procedure,
wherein the mask layer comprises a layer of irregular thickness formed prior to the plasma etch procedure, wherein the layer of irregular thickness acts as the etch mask for the plasma etch procedure, wherein the probe tip body is produced by producing a mold in a substrate and by depositing the probe material in the mold, and wherein at least one of: (i) seed particles are deposited in the mold prior to depositing the probe material therein and wherein the layer of irregular thickness comprises the seed particles, or (ii) the layer of irregular thickness comprises compounds formed spontaneously on a surface of the probe tip body after the production of the probe tip body and prior to the plasma etch procedure.

2. The method according to claim 1 , wherein the layer of irregular thickness further comprises compounds formed spontaneously on a surface of the mold.

3. The method according to claim 1 , wherein the plasma etch procedure comprises:
a first etch process performed during a first etch time and configured to produce craters in the layer of irregular thickness; and
a second etch process performed during a second etch time that is longer than the first etch time and configured to produce the one or more tip portions.

4. The method according to claim 1 , wherein the probe tip body is attached to a cantilever, wherein particles of the cantilever are sputtered during the plasma etch procedure and deposited onto the probe tip body, and wherein the sputtered particles of the cantilever contribute to the formation of the mask layer during a remainder of the plasma etch procedure.

5. The method according to claim 1 , wherein at an end of the plasma etch procedure, the one or more tip portions are distributed across a totality of the probe tip body.

6. The method according to claim 1 , wherein the probe tip body is pyramid-shaped, and wherein, at an end of the plasma etch procedure, the one or more tip portions are present on an apex area of the probe tip body and no tip portions are present on side planes of the probe tip body because:
a higher concentration of masking particles is deposited on the apex area than on the side planes during the plasma etch procedure; or
the probe tip body comprises a core and, on the core, a layer of the probe material, wherein a thickness of the layer of the probe material is higher on the apex area than on the side planes such that, at the end of the plasma etch procedure, the probe material is removed from the side planes.

7. The method according to claim 1 , wherein the probe material is diamond.

8. The method according to claim 1 , further comprising the following steps performed after the plasma etch procedure:
depositing a capping layer on the one or more tip portions, thereby covering the one or more tip portions entirely; and
subjecting the one or more tip portions to an additional plasma etch process configured to remove the capping layer from a tip area of the one or more tip portions, while substantially maintaining the capping layer around a lateral surface of the one or more tip portions, wherein the tip area includes apexes of the one or more tip portions.

9. A probe tip suitable for scanning probe microscopy (SPM), comprising a probe tip body comprising at least an outer layer of a probe material and having an apex area, wherein a plurality of tip portions formed of the probe material are distributed across a totality of the probe tip body, wherein each of the tip portions is smaller and has a higher aspect ratio than the apex area of the probe tip body, wherein the tip portions comprise a capping layer on their outer surface except on a tip area of the tip portions, and wherein the tip area comprises an apex of the tip portions.

10. A probe comprising:
a cantilever;
a holder to which the cantilever is attached; and
a probe tip attached to a distal end of the cantilever, wherein the probe tip is suitable for scanning probe microscopy (SPM) and comprises a probe tip body comprising at least an outer layer of a probe material and having an apex area, wherein a plurality of tip portions formed of the probe material are distributed across a totality of the probe tip body, wherein each of the tip portions is smaller and has a higher aspect ratio than the apex area of the probe tip body, wherein the tip portions comprise a capping layer on their outer surface except on a tip area of the tip portions, and wherein the tip area comprises an apex of the tip portions.

Assignees

• Imec Vzw
• Univ Leuven Kath

Inventors

• Hantschel Thomas
• Boehme Thijs

Classifications

• G01Q70/06

  Probe tip arrays · CPC title

• G01Q70/14 Primary

  Particular materials · CPC title

• C30B25/18

  characterised by the substrate · CPC title

• C30B25/04

  Pattern deposit, e.g. by using masks · CPC title

• G01Q60/02

  Multiple-type SPM, i.e. involving more than one SPM techniques · CPC title