Solid state membrane channel device for the measurement and characterization of atomic and molecular sized samples

• US 6,616,895 B2
• Filed: 03/23/2001
• Issued: 09/09/2003
• Est. Priority Date: 03/23/2000
• Status: Expired due to Fees

• Current Assignee: Advanced Research Corporation
• Original Assignee: Advanced Research Corporation
• Inventors: Wagner, Gregory L., Dugas, Matthew P.
• Primary Examiner(s): Warden, Jill
• Assistant Examiner(s): SIEFKE, SAMUEL P
• Application Number:
  US09/815,461
• Publication Number:
  US 20020025277A1
• Time in Patent Office: 900 Days
• Field of Search: 436/2, 436/72, 436/514, 436/63, 436/86, 436/89, 436/149, 436/150, 436/151, 436/180, 422/50, 422/68.1, 422/73, 422/82.01, 422/82.02, 438/49, 435/4, 435/6, 435/287.2, 435/285.2, 435/287.3
• US Class Current: 422/82.01
• CPC Class Codes: B81C 1/00087 Holes
• CPC Class Codes: G01N 33/48721 Investigating individual macromolecules, e.g. by translocation through nanopores Coulter counters in general G01N15/12; fabrication methods for nanoscale apertures B81B1/00; sequencing of nucleic acids C12Q1/68
• CPC Class Codes: Y10S 977/721 On a silicon substrate
• CPC Class Codes: Y10S 977/781 Possessing nonosized surface openings that extend partially into or completely through the host material

Abstract

A solid state device is formed through thin film deposition techniques which results in a self-supporting thin film layer that can have a precisely defined channel bored therethrough. The device is useful in the chacterization of polymer molecules by measuring changes in various electrical characteristics as molecules pass through the channel. To form the device, a thin film layer having various patterns of electrically conductive leads are formed on a silicon substrate. Using standard lithography techniques, a relatively large or micro-scale aperture is bored through the silicon substrate which in turn exposes a portion of the thin film layer. This process does not affect the thin film. Subsequently, a high precision material removal process is used (such as a focused ion beam) to bore a precise nano-scale aperture through the thin film layer that coincides with the removed section of the silicon substrate.

Claims

1. A device for the characterization of polymer molecules, comprising:

a substrate forming a base of the device, the substrate including an aperture therethrough;

having a nano-scale thickness disposed on the substrate and extending across the aperture so that the thin film is self supporting over an area defined by the aperture;

a nano-scale channel through the thin film in the area defined by the aperture, wherein the channel is sized so as to allow passage of polymer molecules therethrough one at a time so that as a polymer molecule passes therethrough a given monomer will cause a detectable change in the thin film wherein the detectable change will characterize the monomer.

2. The device of claim 1, further comprising

a container for holding a fluid medium having a quantity of polymer molecules disposed therein, wherein the substrate including the thin film is disposed within the container and divides the fluid medium into a first pool and a second pool wherein polymer molecules are directed from the first pool through the channel and into the second pool by generating a voltage differential across the thin film.

3. The device of claim 1, further comprising:

a first electrically conductive layer disposed within the thin film so as to form a first set of electrically independent leads, wherein each lead has a first end and a second end and the first end of each lead is proximate the channel.

4. The device of claim 3 wherein the first end of each lead of the first set forms a portion of a perimeter of the channel.

5. The device of claim 3 wherein the first set of electrically independent leads comprises two leads positioned on opposite sides the channel.

6. The device of claim 3 wherein the first set of electrically independent leads comprises four leads positioned evenly around the channel in a quadrapole arrangement.

7. The device of claim 3, further comprising:

a second electrically conductive layer disposed within the thin film so as to form a second set of electrically independent leads, wherein each lead has a first end and a second end and the first end of each lead is proximate the channel.

8. The device of claim 7 wherein the first set of leads is separated from the second set of leads by a dielectric layer.

9. The device of claim 7 wherein the first end of each lead of the second set forms a portion of a perimeter of the channel.

10. The device of claim 7 wherein the second set of electrically independent leads comprises two leads positioned on opposite sides the channel.

11. The device of claim 7 wherein the second set of electrically independent leads comprises four leads positioned evenly around the channel in a quadrapole arrangement.

12. The device of claim 1, further comprising:

a first electrically conductive layer disposed within the thin film so as to form a first electrical lead;

a second electrically conductive layer disposed within the thin film so as to form a second electrical lead, wherein the second electrically conductive layer is separated from the first electrically conductive layer by a dielectric layer, so that the channel is formed to pass through the first electrically conductive layer, the dielectric layer and the second electrically conductive layer.

13. The device of claim 1 where the substrate is silicon.

14. The device of claim 1 wherein the aperture has micro-scale dimensions and the channel has nano-scale dimensions.

15. The device of claim 1 wherein the channel has a diameter less than approximately 10 nm.