Sensors for electrochemical, electrical or topographical analysis
AssigneeThe Board of Trustees of the Leland Stanford Junior University
InventorsFriedrich Prinz, Ye Tao, Rainer Fasching, Ralph Greco, Kyle Hammerick, Robert Smith
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Abstract
Sensors and systems for electrical, electrochemical, or topographical analysis, as well as methods of fabricating these sensors are provided. The sensors include a cantilever and one or more probes, each of which has an electrode at its tip. The tips of the probes are sharp, with a radius of curvature of less than about 50 nm. In addition, the probes have a high aspect ratio of more than about 19:1. The sensors are suitable for both Atomic Force Microscopy and Scanning Electrochemical Microscopy.
Claims27
A sensor for electrical, electrochemical or topographical analysis, comprising:
- a) a cantilever with a top and a bottom surface;
- and
- b) one or more probes, wherein each of said probes has a first end and a second end, wherein said first end of said probe comprises an electrode and has a radius of curvature of less than about 50 nm, wherein said second end of said probe is connected to said top surface of said cantilever, and wherein a ratio of the distance between said first end of said probe and said second end of said probe and the diameter of said second end of said probe is more than about 19:1.
A system for electrical, electrochemical or topographical analysis of a sample, comprising:
- a) a sensor comprising a cantilever with a top and bottom surface and one or more probes, wherein each of said probes has a first and second end, wherein said first end of said probe comprises an electrode and has a radius of curvature of less than about 50 nm, wherein said second end of said probe is connected to said top surface of said cantilever, and wherein a ratio of the distance between said first end of said probe and said second end of said probe and the diameter of said second end of said probe is more than about 19:1.
- b) a manipulator operably connected to said sensor for manipulating said sensor;
- c) a signal processing chip including signal amplifiers, wherein said signal processing chip is electrically interfaced with said sensor for processing data collected by said sensor;
- d) a stage having a surface for immobilizing and supporting said sample;
- and
- e) a microscope for optical visualization of said sensor and said sample.
A method of fabricating a sensor for electrical, electrochemical or topographical analysis, comprising:
- a) shaping one or more High-Aspect Ratio Silicon tips in a silicon wafer;
- b) embedding said one or more tips in a uniform layer of silicon nitride;
- c) coating said silicon nitride layer with a non-uniform coating of photoresist;
- d) removing said non-uniform coating of photoresist and said silicon nitride from a top section of said one or more embedded tips.
- e) patterning electrodes on said top section of said one or more embedded tips;
- f) passivating said electrodes with an isolation layer;
- g) patterning a cantilever in said silicon nitride layer
- h) etching said top section of said one or more embedded tips to generate an ultra-micro electrode;
- and
- i) releasing said cantilever with said one or more embedded tips from said silicon wafer.
Dependencies are inferred from the claim text.