Miniaturized cantilever probe for scanning probe microscopy and fabrication thereof

Patent metadata

Field	Value
Publication number	US-9709597-B2
Application number	US-201414305588-A
Country	US
Kind code	B2
Filing date	Jun 16, 2014
Priority date	Aug 31, 2012
Publication date	Jul 18, 2017
Grant date	Jul 18, 2017

Abstract

Cantilever probes are formed from a multilayer structure comprising an upper substrate, a lower substrate, an interior layer, a first separation layer, and a second separation layer, wherein the first separation layer is situated between the upper substrate and the interior layer, the second separation layer is situated between the lower substrate and the interior layer, and wherein the first and the second separation layers are differentially etchable with respect to the first and the second substrates, the interior layer. The upper substrate is a first device layer from which a probe tip is formed. The interior layer is a second device layer from which a cantilever arm is formed. The lower substrate is a handle layer from which a handle, or base portion, is formed. Patterning and etching processing of any layer is isolated from the other layers by the separation layers.

First claim

What is claimed is:

1. A cantilever probe for use with a scanning probe microscope (SPM), the cantilever probe comprising:
a base portion formed from a bulk semiconductor material;
a cantilever arm formed entirely of the same bulk semiconductor material and having a proximal end portion situated over the base portion and a distal end portion protruding beyond a periphery of the base portion;
a lower separation layer situated between the base portion and the proximal end portion of the cantilever arm, the lower separation layer being differentially etchable by an etch rate ratio of at least 100 relative to an etch rate of the cantilever arm and the base portion;
a probe tip situated directly over a portion of the cantilever arm, wherein the portion is entirely between the proximal end portion and the distal end portion; and
an upper separation layer extending parallel to the lower separation layer, wherein the upper separation layer is situated between the probe tip and the cantilever arm, the upper separation layer being differentially etchable relative to the cantilever arm,
wherein the probe tip is a voidless pyramidal structure formed from the bulk semiconductor material extending from the upper separation layer.

2. The cantilever probe of claim 1 , wherein the upper separation layer is differentially etchable relative to the probe tip.

3. The cantilever probe of claim 1 , wherein at least a portion of the upper separation layer is formed from a conductive material.

4. The cantilever probe of claim 1 , wherein the upper separation layer is fusion bonded to the probe tip.

5. The cantilever probe of claim 1 , wherein the upper separation layer is formed from an oxide grown on a layer of semiconductor material from which the probe tip is later formed.

6. The cantilever probe of claim 1 , wherein the upper separation layer is formed from an oxide grown on a layer of semiconductor material from which the cantilever arm is later formed.

7. The cantilever probe of claim 1 , wherein the cantilever arm includes a single layer of semiconductor material.

8. The cantilever probe of claim 1 , wherein the cantilever arm is formed from a conductive material.

9. The cantilever probe of claim 1 , wherein the cantilever arm includes a single layer of low-stress nitride film.

10. The cantilever probe of claim 1 , wherein the cantilever arm has a thickness of between 30 nm and 300 nm.

11. The cantilever probe of claim 1 , wherein the cantilever arm has a length of between 5 and 30 microns and a maximum width of between 2 and 15 microns.

12. The cantilever probe of claim 1 , wherein the cantilever arm has a length dimension, a width dimension, and a thickness dimension, wherein in a reference plane defined by the length dimension and the width dimension, the cantilever arm has a paddle profile that includes a face portion at the distal end and a neck portion between the face portion and the base portion, the neck portion having a smaller width dimension than the face portion.

13. The cantilever probe of claim 1 , wherein the cantilever arm has a length dimension, a width dimension, and a thickness dimension, wherein in a reference plane defined by the length dimension and the width dimension, the cantilever arm includes a neck portion and a shoulder portion, wherein the shoulder portion is situated at the proximal end of the cantilever arm and protrudes in the distal direction beyond a periphery of the base portion, and wherein the neck portion has a substantially smaller width dimension than the shoulder portion.

14. The cantilever probe of claim 13 , wherein the neck portion that protrudes in the distal direction beyond a periphery of the base portion contributes no more than a nominal effect on a spring constant of the cantilever arm.

15. The cantilever probe of claim 1 , wherein the upper separation layer is non-metallic.

16. The cantilever probe of claim 15 , wherein the cantilever arm is made of one of the group consisting of silicon and silicon nitride, and the upper separation layer is made from silicon dioxide.

Assignees

• Bruker Nano Inc
• Bruker-Nano Inc

Inventors

• Wang Weijie
• Su Chanmin

Classifications

• G01Q70/02

  Probe holders · CPC title

• G01Q70/08

  Probe characteristics · CPC title

• G01Q60/38 Primary

  Probes, their manufacture, or their related instrumentation, e.g. holders · CPC title

• G01Q70/00

  General aspects of SPM probes, their manufacture or their related instrumentation, insofar as they are not specially adapted to a single SPM technique covered by group G01Q60/00 · CPC title

• G01Q70/16

  Probe manufacture · CPC title