US5444244A
Expired / Lapsed
US
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Piezoresistive cantilever with integral tip for scanning probe microscope
Assignee: Teknekron Sensor Development Corp
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Filing: 1993-06-03
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Granted: 1995-08-22
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Expires: 2013-06-03
Abstract
Abstract A cantilever for a scanning probe microscope is disclosed. The cantilever includes a piezoresistor for detecting the deflection of the cantilever, and a tip which is formed integrally with the cantilever. A process of fabricating such a cantilever is also disclosed, the process yielding a tip which has a high aspect ratio and a small radius of curvature at its apex. A combined atomic force/lateral force microscope including two or more piezoresistors responsive to both the bending and torsion of the cantilever is also disclosed.
Inventors
- 👤 Michael D. Kirk
- 👤 Ian R. Smith
- 👤 Marco Tortonese
- 👤 Sean S. Cahill
- 👤 Timothy G. Slater
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 11:41
CPC Classifications
G; G01; G01Q; G01Q20/00; G01Q20/04; B; B82; B82Y; B82Y35/00; G01Q60/00; G01Q60/24; G01Q60/38; Y; Y10; Y10S; Y10S977/00; Y10S977/84; Y10S977/849; Y10S977/86; Y10S977/873
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
79 words
A cantilever for use in a scanning probe microscope, said cantilever comprising: a fixed end, said fixed end being attached to a base member; a tip located near the free end of the cantilever; a piezoresistor positioned in the cantilever such that the resistance of the piezoresistor varies when the free end of the cantilever is deflected; and a shielding layer applied to a surface of the cantilever to protect the piezoresistor from electrical and optical sources of noise.
Claim 2
Dependent Claim
79 words
A cantilever for use in a scanning probe microscope, said cantilever comprising: a fixed end, said fixed end being attached to a base member; a tip located near the free end of the cantilever; a piezoresistor positioned in the cantilever such that the resistance of the piezoresistor varies when the free end of the cantilever is deflected; and a shielding layer applied to a surface of the cantilever to protect the piezoresistor from electrical and optical sources of noise.
Claim 3
Dependent Claim
31 words
The cantilever of claim 1 wherein the shielding layer comprises a material from the group consisting of a metallic substance, an optically absorbing material, a reflective dielectric layer, and a polymer.
Claim 4
Dependent Claim
44 words
A cantilever for use in a scanning probe microscope and a semiconductor die attached to a fixed end of said cantilever, said die comprising a front face, two side faces, truncated corners being formed at intersections between said front face and said side faces.
Claim 5
Dependent Claim
44 words
A cantilever for use in a scanning probe microscope and a semiconductor die attached to a fixed end of said cantilever, said die comprising a front face, two side faces, truncated corners being formed at intersections between said front face and said side faces.
Claim 6
Dependent Claim
10 words
The cantilever of claim 3 wherein said die comprises silicon.
Claim 7
Dependent Claim
98 words
A cantilever for use in a scanning probe microscope, said cantilever comprising: a fixed end and a free end, said fixed end being attached to a base member; a tip located near the free end of the cantilever; and a piezoresistor positioned in the cantilever such that the resistance of the piezoresistor varies when the free end of the cantilever is deflected, a notch being formed in a region of the cantilever near the piezoresistor so as to increase the change in resistance of said piezoresistor in response to a deflection of the free end of the cantilever.
Claim 8
Dependent Claim
98 words
A cantilever for use in a scanning probe microscope, said cantilever comprising: a fixed end and a free end, said fixed end being attached to a base member; a tip located near the free end of the cantilever; and a piezoresistor positioned in the cantilever such that the resistance of the piezoresistor varies when the free end of the cantilever is deflected, a notch being formed in a region of the cantilever near the piezoresistor so as to increase the change in resistance of said piezoresistor in response to a deflection of the free end of the cantilever.
Claim 9
Dependent Claim
23 words
The cantilever of claim 5 wherein the cantilever comprises two legs and a notch is formed in each leg adjacent to the piezoresistor.
Claim 10
Dependent Claim
81 words
A cantilever for use in a scanning probe microscope, said cantilever comprising: a fixed end and a free end, said fixed end being attached to a base member; a tip located near the free end of the cantilever; two legs oriented parallel to a longitudinal axis of the cantilever; and a piezoresistor located in at least one of said legs, said at least one leg having a thinner portion which is less resistant to bending than the remainder of said leg.
Claim 11
Dependent Claim
81 words
A cantilever for use in a scanning probe microscope, said cantilever comprising: a fixed end and a free end, said fixed end being attached to a base member; a tip located near the free end of the cantilever; two legs oriented parallel to a longitudinal axis of the cantilever; and a piezoresistor located in at least one of said legs, said at least one leg having a thinner portion which is less resistant to bending than the remainder of said leg.
Claim 12
Dependent Claim
82 words
A cantilever for use in a scanning probe microscope, said cantilever comprising: a fixed end and a free end, said fixed end being attached to a base member; a tip located near the free end of the cantilever; and a piezoresistor positioned in the cantilever such that the resistance of the piezoresistor varies when the free end of the cantilever is deflected, one or more thickness variations being formed in a section of the cantilever to stiffen that section of the cantilever.
Claim 13
Dependent Claim
82 words
A cantilever for use in a scanning probe microscope, said cantilever comprising: a fixed end and a free end, said fixed end being attached to a base member; a tip located near the free end of the cantilever; and a piezoresistor positioned in the cantilever such that the resistance of the piezoresistor varies when the free end of the cantilever is deflected, one or more thickness variations being formed in a section of the cantilever to stiffen that section of the cantilever.
Claim 14
Dependent Claim
14 words
The cantilever of claim 8 wherein the thickness variations comprise a plurality of corrugations.
Claim 15
Dependent Claim
164 words
A cantilever for use with a lateral force microscope, said cantilever comprising: a fixed end and a free end, said fixed end being attached to a base member; a tip located near the free end of the cantilever; first and second piezoresistors positioned in the cantilever such that a lateral force on the tip produces a decrease in the resistance of the first piezoresistor and an increase in the resistance of the second piezoresistor and a perpendicular force on the tip produces a change in the same sense in the respective resistances of the first and second piezoresistors; and output circuitry connected to the first and second piezoresistors, the output circuitry being for delivering a first output signal responsive to a torsional movement of the cantilever and thereby representative of a magnitude of the lateral force on the tip, and a second output signal responsive to a bending of the cantilever and thereby representative of the magnitude of the perpendicular force on the tip.
Claim 16
Dependent Claim
164 words
A cantilever for use with a lateral force microscope, said cantilever comprising: a fixed end and a free end, said fixed end being attached to a base member; a tip located near the free end of the cantilever; first and second piezoresistors positioned in the cantilever such that a lateral force on the tip produces a decrease in the resistance of the first piezoresistor and an increase in the resistance of the second piezoresistor and a perpendicular force on the tip produces a change in the same sense in the respective resistances of the first and second piezoresistors; and output circuitry connected to the first and second piezoresistors, the output circuitry being for delivering a first output signal responsive to a torsional movement of the cantilever and thereby representative of a magnitude of the lateral force on the tip, and a second output signal responsive to a bending of the cantilever and thereby representative of the magnitude of the perpendicular force on the tip.
Claim 17
Dependent Claim
28 words
The cantilever of claim 10 wherein the magnitude of the second output signal is determined by a sum of the respective resistances of the first and second piezoresistors.
Claim 18
Dependent Claim
22 words
The cantilever of claim 10 wherein the cantilever comprises a plurality of legs, a piezoresistor being positioned in each of the legs.
Claim 19
Dependent Claim
11 words
The cantilever of claim 12 wherein the cantilever comprises two legs.
Claim 20
Dependent Claim
64 words
The cantilever of claim 10 wherein the first piezoresistor comprises a first longitudinal piezoresistor and the second piezoresistor comprises a a second longitudinal piezoresistor, said cantilever further comprising a first transverse piezoresistor and a second transverse piezoresistor, the longitudinal piezoresistors being oriented parallel to a main axis of the cantilever and the transverse piezoresistors being oriented perpendicular to the main axis of the cantilever.
Claim 21
Dependent Claim
44 words
The cantilever of claim 14 comprising a first leg and a second leg, the first longitudinal piezoresistor and the first transverse piezoresistor being positioned in the first leg, and the second longitudinal piezoresistor and the second transverse piezoresistor being positioned in the second leg.
Claim 22
Dependent Claim
28 words
The cantilever of claim 15 wherein the first and second longitudinal resistors and the first and second transverse resistors are interconnected so as to form a bridge circuit.
Claim 23
Dependent Claim
25 words
The cantilever of claim 16 wherein said cantilever comprises a plurality of legs, each of said legs comprising a longitudinal piezoresistor and a transverse piezoresistor.
Claim 24
Dependent Claim
27 words
The cantilever-of claim 10 wherein the magnitude of the first output signal is determined by a difference between the respective resistances of the first and second piezoresistors.
Claim 25
Dependent Claim
81 words
A cantilever for use in a scanning probe microscope, said cantilever comprising: a fixed end and a free end, said fixed end being attached to a base member; a tip located near the free end of the cantilever, said tip comprising a relatively narrow waist portion and a relatively wide head portion; and a piezoresistor within the cantilever, the piezoresistor positioned such that a resistance of the piezoresistor varies when the tip of the cantilever is subjected to a lateral force.
Claim 26
Dependent Claim
81 words
A cantilever for use in a scanning probe microscope, said cantilever comprising: a fixed end and a free end, said fixed end being attached to a base member; a tip located near the free end of the cantilever, said tip comprising a relatively narrow waist portion and a relatively wide head portion; and a piezoresistor within the cantilever, the piezoresistor positioned such that a resistance of the piezoresistor varies when the tip of the cantilever is subjected to a lateral force.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-08-21 | 1999-02-20 | 1999-08-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-08-21 | 2003-02-20 | 2003-08-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-08-21 | 2007-02-20 | 2007-08-22 | $7700.00 | Window Closed / Lapsed |