Thermal probe

Patent metadata

Field	Value
Publication number	US-10466272-B2
Application number	US-201615736154-A
Country	US
Kind code	B2
Filing date	Jun 14, 2016
Priority date	Jun 15, 2015
Publication date	Nov 5, 2019
Grant date	Nov 5, 2019

Abstract

Thermal probe ( 10 ) for a scanning thermal microscope ( 100 ), use, and process of manufacturing. The thermal probe ( 10 ) comprises a single-material (M 1 ) thermal conducting body ( 12 ) consisting of a probe frame ( 14 ) ending in a probe tip ( 11 ). A bi-material (M 1 ,M 2 ) cantilever strip ( 13 ) is connected to the probe frame ( 14 ) in thermal communication with the probe tip ( 11 ). The cantilever strip ( 13 ) in unbended state lies in-plane (X,Z) with the probe tip ( 11 ). The cantilever strip ( 13 ) comprises layers of material (M 1 ,M 2 ) having different coefficients of thermal expansion configured to bend the cantilever strip ( 13 ) with respect to the single-material thermal conducting body ( 12 ) as a function of the heat exchange (H) between the probe tip ( 11 ) and the microscopic structure ( 2 ) for measuring heat exchange (H) with a sample interface ( 1 ) by means of measuring the bending of the cantilever strip ( 13 ).

First claim

The invention claimed is:

1. A thermal probe for a scanning thermal microscope, the thermal probe comprising:
a thermal conducting body consisting of a probe frame ending in a probe tip in use arranged along a probe direction perpendicular to a sample interface for measuring a microscopic structure on the sample interface in vicinity of the probe tip by heat exchange between the probe tip and the microscopic structure; and
a bi-material cantilever strip connected to the probe frame in thermal communication with the probe tip through the thermal conducting body, wherein the probe direction of the probe tip lies in-plane with the cantilever strip in unbended state and the probe frame, wherein the cantilever strip comprises layers of material having different coefficients of thermal expansion configured to bend the cantilever strip with respect to the thermal conducting body as a function of the heat exchange between the probe tip and the microscopic structure for measuring the heat exchange by means of measuring the bending of the cantilever strip.

2. The thermal probe according to claim 1 , wherein the probe frame comprises one or more single-material support arms for supporting an end of the thermal probe comprising the probe tip over the sample interface, wherein the cantilever strip is configured to bend independently of the one or more support arms.

3. The thermal probe according to claim 1 , wherein the cantilever strip in unbended state extends sideways from the probe frame perpendicular to the probe direction, wherein the cantilever strip is configured to bend in-plane with the sample interface perpendicular to the probe direction independently of the single-material probe frame, wherein the cantilever strip is distanced from the probe tip with the probe frame there between.

4. The thermal probe according to claim 1 , wherein the cantilever strip is distanced from the probe tip with at least part of the single-material probe frame there between.

5. The thermal probe according to claim 1 , wherein the probe frame is more rigid than the cantilever strip.

6. The thermal probe according to claim 1 , wherein the probe tip, probe frame, and cantilever strip in unbended state are substantially flat extending in a single plane.

7. The thermal probe according to claim 1 , wherein the probe frame comprises a single layer of a first material; wherein the cantilever strip extends from the probe frame as a strip of the first material having reduced thickness compared to that of the probe frame, wherein a layer of a second material is bonded to the extended strip of the first material together forming the bi-material cantilever strip.

8. The thermal probe according to claim 1 , wherein the probe tip is formed at a flat triangular ending of the probe frame.

9. The thermal probe according to, wherein the probe tip has a point radius of less than a hundred micron.

10. A scanning thermal microscope comprising:
a thermal probe for a scanning thermal microscope, the thermal probe comprising:
a thermal conducting body consisting of a probe frame ending in a probe tip in use arranged along a probe direction perpendicular to a sample interface for measuring a microscopic structure on the sample interface in vicinity of the probe tip by heat exchange between the probe tip and the microscopic structure; and
a bi-material cantilever strip connected to the probe frame in thermal communication with the probe tip through the thermal conducting body, wherein the probe direction of the probe tip lies in-plane with the cantilever strip in unbended state and the probe frame, wherein the cantilever strip comprises layers of material having different coefficients of thermal expansion configured to bend the cantilever strip with respect to the thermal conducting body as a function of the heat exchange between the probe tip and the microscopic structure for measuring the heat exchange by means of measuring the bending of the cantilever strip; and
an actuator stage holding the thermal probe by attachment to the probe frame opposite the ending of the probe tip;
wherein the probe frame does not bend under the influence of temperature variation at least between the ending of the probe tip and the attachment to the actuator stage.

11. The scanning thermal microscope according to claim 10 , comprising:
a light source configured to direct a light beam onto the cantilever strip; and
a position sensitive detector configured to measure an amount of deflection of the light beam resulting from a bending of the cantilever strip for measuring the heat exchange of the probe tip with a microscopic structure on a sample interface.

12. The scanning thermal microscope according to claim 10 , comprising a controller configure to control the actuator stage based on a measured deflection of the light beam caused by the heat induced bending of the cantilever strip.

13. The scanning thermal microscope according to claim 10 , comprising a heating plate below the sample interface to be measured.

14. A method of manufacturing a thermal probe comprising: a thermal conducting body consisting of a probe frame ending along a probe tip arranged in a probe direction perpendicular to a sample interface, and a bi-material cantilever strip connected to the probe frame in thermal communication with the probe tip through its thermal conducting body, wherein the cantilever strip in unbended state lies in-plane with the probe tip, wherein the cantilever strip comprises layers of material having different coefficients of thermal expansion configured to bend the cantilever strip with respect to the thermal conducting body as a function of temperature, the method comprising:
providing a wafer consisting of a first material;
etching a protruding contour of the thermal probe into the wafer, wherein the protruding contour comprises a connected flat shape of the probe frame, the probe tip, and the cantilever strip;
locally thinning the flat shape of the cantilever strip; and
depositing a second material onto the thinned cantilever strip to form the bi-material cantilever strip.

Assignees

• Nederlandse Organisatie Voor Toegepast—Natuurwetenschappelijk Onderzoek Tno
• TNO

Inventors

• Marnani Hamed Sadeghian
• Bijster Roy Jacobus Franciscus

Classifications

• G01Q60/58 Primary

  SThM [Scanning Thermal Microscopy] or apparatus therefor, e.g. SThM probes · CPC title

• G01K5/62

  the solid body being formed of compounded strips or plates, e.g. bimetallic strip · CPC title

• G01K5/64

  Details of the compounds system · CPC title