Method and device for controlling a scanning probe microscope

Patent metadata

Field	Value
Publication number	US-9500670-B2
Application number	US-201314651233-A
Country	US
Kind code	B2
Filing date	Dec 12, 2013
Priority date	Dec 12, 2012
Publication date	Nov 22, 2016
Grant date	Nov 22, 2016

Abstract

The present invention relates to a method for controlling a scanning probe microscope having a probe ( 2 ) with a tip ( 21 ) for interacting with a sample ( 4 ), and a nanoscanner ( 1 ) for retaining the sample ( 4 ) or the probe ( 2 ), comprising the steps of monitoring the extension of the piezo element ( 1 ) along a first direction (R) along which the tip ( 21 ) is moved towards the sample ( 4 ), and adjusting the level of the probe ( 2 ) along the first direction (R) by means of an additional actuator ( 3 ), when the nanoscanner ( 1 ) exhibits an extension below or above a threshold value. The invention further relates to a device ( 100 ) for controlling a scanning probe microscope.

First claim

The invention claimed is:

1. A method for controlling a scanning probe microscope having a probe ( 2 ) with a tip ( 21 ) for interacting with a sample ( 4 ), and a nanoscanner ( 1 ) for retaining said sample ( 4 ) or said probe ( 2 ), comprising the steps of:
monitoring the extension of said nanoscanner ( 1 ) along a first direction (R), along which said tip ( 21 ) is moved towards said sample ( 4 ), and
adjusting a level of said probe ( 2 ) along said first direction (R) by means of an additional actuator ( 3 ), when said nanoscanner ( 1 ) exhibits an extension below or above a threshold value, and
further comprising the steps of:
a) measuring a force curve on said sample, wherein said force curve comprises an approaching curve and a retracting curve,
b) detecting an optimal baseline part of said force curve,
c) optionally detecting a contact point of said force curve,
d) comparing said approaching curve and/or said retracting curve with said optimal baseline part, particularly in proximity of said contact point, and
e) based on said comparison of step d), adjusting one of:
said level of said probe; the lateral position of said probe; or an angle (α), wherein said angle (α) is monitored between a second direction (R 2 ) and the normal (N) of a surface of said sample ( 4 ) at a point ( 53 ) of said surface, wherein said probe ( 2 ) is moving along said second direction (R 2 ) towards said point ( 53 ), and said additional actuator ( 3 ), and at least a second additional actuator ( 32 ) is controlled such that said angle (α) approaches a predefined desired angle, wherein particularly said desired angle is zero.

2. The method according to claim 1 , wherein said nanoscanner ( 1 ) is a piezo element.

3. The method according to claim 1 , wherein said probe ( 2 ) is a cantilever.

4. The method according to claim 1 , wherein said adjusting is performed by lowering or lifting said probe ( 2 ) or by lowering or lifting said sample ( 4 ).

5. The method according to claim 1 , wherein said level is adjusted when said nanoscanner ( 1 ) exhibits an extension lower than 20% or higher than 80% of its maximal extension.

6. The method according to claim 1 , wherein said level is adjusted by lowering or lifting said probe ( 2 ) or said sample ( 4 ) by 10 to 30% of the maximal extension of said nanoscanner ( 1 ).

7. The method according to claim 1 , wherein said level is adjusted whenever said nanoscanner ( 1 ) exhibits an extension that is 50 nm, 100 nm, 200 nm, 500 nm, 700 nm, 1μ or 2 μm
smaller than said nanoscanner's maximal extension or
larger than said nanoscanner's maximal retraction.

8. The method according to claim 1 , wherein said level is adjusted by lowering or lifting said probe ( 2 ) or said sample ( 4 ) by a distance ranging from 50 nm to 3 μm.

9. The method according to claim 1 , wherein said additional actuator ( 3 ), said second additional actuator ( 32 ) and a third additional actuator ( 33 ) are controlled such that said current angle (α) approaches said predefined desired angle.

Assignees

• Univ Basel

Inventors

• Lim Roderick
• Plodinec Marija
• Loparic Marko
• Oehler Pascal
• Camenzind Leon

Classifications

• G01Q30/06

  for error compensation · CPC title

• G01Q20/00 Primary

  Monitoring the movement or position of the probe · CPC title

• G01Q10/065 Primary

  Feedback mechanisms, i.e. wherein the signal for driving the probe is modified by a signal coming from the probe itself · CPC title

• G01Q10/00

  Scanning or positioning arrangements, i.e. arrangements for actively controlling the movement or position of the probe · CPC title