US4969978A
Expired / Lapsed
US
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Apparatus and method for tunnel current measurement observed simultaneously with electrochemical measurement
Assignee: Hitachi High-Tech Analysis Corp
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Filing: 1988-11-23
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Granted: 1990-11-13
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Expires: 2008-11-23
Abstract
Abstract Apparatus and method for tunnel current measurement observed simultaneously with electrochemical measurement using an electrochemical cell. The electrochemical cell holds a tip, a counter electrode, a reference electrode and a sample in a solution. In the electrochemical cell, a tunnel current flowing between a sample and the tip is detected while controlling the electrode potential of the sample in a solution for electrochemical measurement. The detected tunnel current is represented as the surface image of the sample during electrochemical reaction.
Inventors
- 👤 Eisuke Tomita
- 👤 Toshihiko Sakuhara
- 👤 Kingo Itaya
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 19:45
CPC Classifications
G; G01; G01Q; G01Q60/00; G01Q60/02; B; B82; B82Y; B82Y35/00; G01Q60/10; G01Q60/16; G01Q60/60; Y; Y10; Y10S; Y10S977/00; Y10S977/84; Y10S977/849; Y10S977/852
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
170 words
An apparatus for effecting tunnel current measurement of a sample within a solution simultaneously with electrochemical measurement thereof, comprising: an electrochemical cell holding a tip, a counter electrode and a reference electrode in a solution; first control means for controlling an electrochemical potential of a sample immersed in the solution with respect to the reference electrode to regulate an electrochemical reaction on a surface of the sample; first detecting means for detecting the value of electrochemical current flowing between the sample and the counter electrode; positioning means for positioning the tip close to the sample surface so that tunnel current flows between the tip and the sample surface; second control means for controlling an electrochemical potential of the tip with respect to the reference electrode to set a potential difference between the tip and the sample effective to flow substantially only tunnel current between the tip and the sample; and second detecting means for detecting the tunnel current flowing due to the potential difference between the tip and the sample.
Claim 2
Independent Claim
170 words
An apparatus for effecting tunnel current measurement of a sample within a solution simultaneously with electrochemical measurement thereof, comprising: an electrochemical cell holding a tip, a counter electrode and a reference electrode in a solution; first control means for controlling an electrochemical potential of a sample immersed in the solution with respect to the reference electrode to regulate an electrochemical reaction on a surface of the sample; first detecting means for detecting the value of electrochemical current flowing between the sample and the counter electrode; positioning means for positioning the tip close to the sample surface so that tunnel current flows between the tip and the sample surface; second control means for controlling an electrochemical potential of the tip with respect to the reference electrode to set a potential difference between the tip and the sample effective to flow substantially only tunnel current between the tip and the sample; and second detecting means for detecting the tunnel current flowing due to the potential difference between the tip and the sample.
Claim 3
Dependent Claim
22 words
An apparatus as claimed in claim 1; wherein the first control means includes means for scanning the electrochemical potential of the sample.
Claim 4
Dependent Claim
22 words
An apparatus as claimed in claim 1; wherein the second control means includes means for scanning the electrochemical potential of the tip.
Claim 5
Dependent Claim
20 words
An apparatus as claimed in claim 1; wherein the counter electrode and the reference electrode are united into one electrode.
Claim 6
Independent Claim
275 words
An apparatus for effecting tunneling current measurement of a sample in a solution simultaneously with electrochemical measurement thereof, comprising: an electrochemical cell holding a tip, a counter electrode and a reference electrode in a solution; first control means for controlling an electrochemical potential of a sample immersed in the solution with respect to the reference electrode to regulate an electrochemical reaction on a surface of the sample; first detecting means for detecting the value of electrochemical current flowing between the sample and the counter electrode; positioning means for positioning the tip close to the sample surface so that tunnel current flows between the tip and the sample surface; second control means for controlling an electrochemical potential of the tip with respect to the reference electrode to set a potential difference between the tip and the sample effective to flow substantially only tunnel current between the tip and the sample; second detecting means for detecting the tunnel current flowing due to the potential difference between the tip and the sample; third control means for controlling the distance between the tip and the sample surface so that the detected tunnel current is maintained substantially constant, the third control means controlling a Z-axis fine adjustment mechanism which drives the tip in a Z direction; fourth control means for controlling the scanning of the tip over the sample surface, the fourth control means controlling an X-axis and Y-axis fine adjustment mechanism which drives the tip in X and Y directions which are both perpendicular to the Z direction; and means for graphically displaying the spatial coordinates of the scanning tip to produce a topological image of the sample surface.
Claim 7
Independent Claim
275 words
An apparatus for effecting tunneling current measurement of a sample in a solution simultaneously with electrochemical measurement thereof, comprising: an electrochemical cell holding a tip, a counter electrode and a reference electrode in a solution; first control means for controlling an electrochemical potential of a sample immersed in the solution with respect to the reference electrode to regulate an electrochemical reaction on a surface of the sample; first detecting means for detecting the value of electrochemical current flowing between the sample and the counter electrode; positioning means for positioning the tip close to the sample surface so that tunnel current flows between the tip and the sample surface; second control means for controlling an electrochemical potential of the tip with respect to the reference electrode to set a potential difference between the tip and the sample effective to flow substantially only tunnel current between the tip and the sample; second detecting means for detecting the tunnel current flowing due to the potential difference between the tip and the sample; third control means for controlling the distance between the tip and the sample surface so that the detected tunnel current is maintained substantially constant, the third control means controlling a Z-axis fine adjustment mechanism which drives the tip in a Z direction; fourth control means for controlling the scanning of the tip over the sample surface, the fourth control means controlling an X-axis and Y-axis fine adjustment mechanism which drives the tip in X and Y directions which are both perpendicular to the Z direction; and means for graphically displaying the spatial coordinates of the scanning tip to produce a topological image of the sample surface.
Claim 8
Dependent Claim
22 words
An apparatus as claimed in claim 5; wherein the first control means includes means for scanning the electrochemical potential of the sample.
Claim 9
Dependent Claim
22 words
An apparatus as claimed in claim 5; wherein the second control means includes means for scanning the electrochemical potential of the tip.
Claim 10
Dependent Claim
20 words
An apparatus as claimed in claim 5; wherein the counter electrode and the reference electrode are united into one electrode.
Claim 11
Independent Claim
145 words
A method for effecting tunnel current measurement of a sample within a solution simultaneously with electrochemical measurement thereof using an electrochemical cell which has a counter electrode, a reference electrode and a tip in a solution, comprising the steps of: (a) setting the electrochemical potential of the sample with respect to the reference electrode to effect electrochemical reaction of the sample; (b) detecting the value of electrochemical current flowing between the sample and the counter electrode; (c) positioning the tip close to the sample surface so that tunnel current flows between the tip and the sample surface; (d) setting the electrochemical potential of the tip with respect to the reference electrode so as to cause substantially only tunnel current to flow between the tip and the sample; and (e) detecting the tunnel current flowing due to the potential difference between the tip and the sample.
Claim 12
Independent Claim
145 words
A method for effecting tunnel current measurement of a sample within a solution simultaneously with electrochemical measurement thereof using an electrochemical cell which has a counter electrode, a reference electrode and a tip in a solution, comprising the steps of: (a) setting the electrochemical potential of the sample with respect to the reference electrode to effect electrochemical reaction of the sample; (b) detecting the value of electrochemical current flowing between the sample and the counter electrode; (c) positioning the tip close to the sample surface so that tunnel current flows between the tip and the sample surface; (d) setting the electrochemical potential of the tip with respect to the reference electrode so as to cause substantially only tunnel current to flow between the tip and the sample; and (e) detecting the tunnel current flowing due to the potential difference between the tip and the sample.
Claim 13
Dependent Claim
22 words
A method as claimed in claim 9; wherein the tunnel current measurement is carried out while maintaining constant the sample electrode potential.
Claim 14
Dependent Claim
30 words
A method as claimed in claim 9; wherein the tunnel current measurement is carried out while maintaining constant the potential between the sample and tip while scanning the sample potential.
Claim 15
Dependent Claim
27 words
A method as claimed in claim 9; wherein the tunnel current measurement is carried out while maintaining constant the sample electrode potential while scanning the tip electrode.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-11-12 | 1994-05-14 | 1994-11-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-11-12 | 1998-05-14 | 1998-11-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-11-12 | 2002-05-14 | 2002-11-13 | $7700.00 | Window Closed / Lapsed |