Use of carbon nanotubes as chemical sensors by incorporation of fluorescent molecules within the tube

• US 6,437,329 B1
• Filed: 10/27/1999
• Issued: 08/20/2002
• Est. Priority Date: 10/27/1999
• Status: Expired due to Fees

• Current Assignee: Advanced Micro Devices SDN Berhad (Advanced Micro Devices, Inc.)
• Original Assignee: Advanced Micro Devices, Inc.
• Inventors: Singh, Bhanwar, Yedur, Sanjay K., Choo, Bryan K.
• Primary Examiner(s): Berman, Jack
• Assistant Examiner(s): FERNANDEZ, KALIMAH
• Application Number:
  US09/428,098
• Time in Patent Office: 1,028 Days
• Field of Search: 250/306, 250/234, 250/252, 250/440.11, 356/73, 356/301
• US Class Current: 850/58
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: B82Y 15/00 Nanotechnology for interacting, sensing or actuating, e.g. quantum dots as markers in protein assays or molecular motors
• CPC Class Codes: B82Y 35/00 Methods or apparatus for measurement or analysis of nanostructures
• CPC Class Codes: G01N 2021/7786 Fluorescence
• CPC Class Codes: G01N 21/6458 Fluorescence microscopy fluorescence microscopes per se G02B21/0076 and G02B21/16
• CPC Class Codes: G01N 21/9501 Semiconductor wafers manufacturing processes per se of semiconductor devices implementing a measuring step H01L22/10
• CPC Class Codes: G01Q 70/12 Nanotube tips
• CPC Class Codes: Y10S 977/843 Gas phase catalytic growth, i.e. chemical vapor deposition
• CPC Class Codes: Y10S 977/844 Growth by vaporization or dissociation of carbon source using a high-energy heat source, e.g. electric arc, laser, plasma, e-beam
• CPC Class Codes: Y10S 977/852 for detection of specific nanostructure sample or nanostructure-related property
• CPC Class Codes: Y10S 977/876 Nanotube tip
• CPC Class Codes: Y10S 977/877 Chemically functionalized

Abstract

A system for analyzing a film and detecting a defect associated therewith includes a scanning probe microscope having a nanotube tip with a material associated therewith which exhibits a characteristic that varies with respect to a film composition at a location corresponding to the nanotube tip. The system also includes a detection system for detecting the material characteristic and a controller operatively coupled to the detection system and the scanning probe microscope. The controller configured to receive information associated with the detected characteristic and use the information to determine whether the film contains a defect at the location corresponding to the nanotube tip. The invention also includes a method of detecting a film composition at a particular location of a film or substrate. The method includes associating a material exhibiting a characteristic which varies with respect to a film composition with a nanotube tip of a scanning probe microscope and detecting the characteristic. The method then includes the step of determining a composition of a portion of the film using the detected characteristic.

Claims

1. A system for analyzing a film and detecting a defect associated therewith, comprising:

a scanning probe microscope including a nanotube tip having a material associated therewith which exhibits a characteristic that varies with respect to a film composition at a location corresponding to the nanotube tip, wherein the material comprises a fluorophore, and wherein the characteristic is a fluorescence having a wavelength that varies over variations in the film composition at the location corresponding to the nanotube tip;

an excitation source for triggering the characteristic which varies with respect to the film composition at the location corresponding to the nanotube tip, wherein the excitation source comprises a light source;

a detection system for detecting the material characteristic; and

a controller operatively coupled to the detection system and the scanning probe microscope, the controller configured to receive information associated with the detected characteristic and use the information to determine whether the film contains a defect at the location corresponding to the nanotube tip.

2. The system of claim 1, wherein the material is in the nanotube.

3. The system of claim 1, wherein the material is on an outside surface of the nanotube.

4. The system of claim 1, wherein the detection system comprises:

a detector which senses the material characteristic; and

a measuring system operatively coupled to the detector, wherein the measuring system converts the detected material characteristic into a data form for processing by the controller.

5. The system of claim 4, wherein the measuring system comprises an analog to digital converter.

6. The system of claim 4, wherein the detector comprises a spectrometer.

7. The system of claim 4, wherein the detector comprises a photodetector.

8. The system of claim 1, further comprising a display operatively coupled to the controller, the display providing a visual indication of information relating to the defect determination.

9. The system of claim 1, wherein the scanning probe microscope is selected from the group consisting of a scanning tunneling microscope, a scanning force microscope and an atomic force microscope.

10. The system of claim 1, wherein the nanotube tip comprises a carbon nanotube.

11. A system for analyzing a film and detecting a defect associated therewith, comprising:

a scanning probe microscope including a nanotube tip having a material associated therewith which exhibits a characteristic that varies with respect to a film composition at a location corresponding to the nanotube tip, wherein the material is an electroluminescent or electrochemiluminescent species, and wherein the characteristic is a fluorescence having an intensity or wavelength that varies over variations in the film composition at the location corresponding to the nanotube tip;

an excitation source for triggering the characteristic which varies with respect to the film composition at the location corresponding to the nanotube tip, wherein the excitation source is a voltage;

a detection system for detecting the material characteristic; and

a controller operatively coupled to the detection system and the scanning probe microscope, the controller configured to receive information associated with the detected characteristic and use the information to determine whether the film contains a defect at the location corresponding to the nanotube tip.

12. A system for determining a film composition at a particular location of a film or substrate, comprising:

a scanning probe microscope including a nanotube tip having a material associated therewith which exhibits a fluorescence upon excitation that varies with respect to a film composition at a location corresponding to the nanotube tip;

an excitation source which directs radiation to the nanotube to excite the material associated therewith;

a detection system for detecting the fluorescence from the nanotube tip; and

a controller operatively coupled to the detection system, the excitation source and the scanning probe microscope, the controller configured to receive information associated with the detected fluorescence and use the information to determine whether the film contains a defect at the location corresponding to the nanotube tip.

13. The system of claim 12, wherein the controller is further configured to compare a fluorescence from the nanotube tip to a predetermined threshold and make the determination whether the film contains a defect at the location based on the comparison.

14. The system of claim 12, wherein the fluorescence comprises one of a fluorescence intensity and a fluorescence wavelength.

15. The system of claim 12, wherein the nanotube tip comprises a carbon nanotube.

16. The system of claim 12, wherein the scanning probe microscope comprises an atomic force microscope.

17. A method of detecting a film composition at a particular location of a film or substrate, comprising the steps of:

associating a material exhibiting a characteristic which varies with respect to a film composition with a nanotube tip of a scanning probe microscope, wherein the material comprises a fluorophore;

detecting the characteristic, wherein detecting the characteristic comprises;

irradiating the nanotube tip having the fluorophore associated therewith; and

sensing a fluorescence from the irradiated nanotube tip, wherein the fluorescence is a function of the film composition at a location corresponding to the nanotube tip, wherein sensing the fluorescence comprises sensing a wavelength of the fluorescence, wherein the wavelength is a function of the film composition; and

determining a composition of a portion of the film using the detected characteristic.

18. The method of claim 17, wherein associating the material with the nanotube tip comprises encapsulating the material in the nanotube.

19. The method of claim 17, wherein associating the material with the nanotube tip comprises depositing the material on an outer surface of the nanotube.

20. The method of claim 17, wherein sensing the fluorescence comprises sensing an intensity of the fluorescence, wherein the intensity is a function of the film composition.

21. The method of claim 17, wherein determining the composition of a portion of the film comprises:

comparing the detected characteristic to a predetermined threshold; and

determining whether the portion of the film contains a defect based on the comparison.

22. The method of claim 17, wherein determining the composition of a portion of the film comprises:

comparing the detected characteristic to another detected characteristic corresponding to another portion of the film; and

determining whether the portion of the film contains a defect based on the comparison.