Field effect transistor

• US 6,798,000 B2
• Filed: 12/18/2002
• Issued: 09/28/2004
• Est. Priority Date: 07/04/2000
• Status: Expired due to Fees

• Current Assignee: Polaris Innovations Limited (Wi-LAN Inc.)
• Original Assignee: Infineon Technologies AG
• Inventors: Haneder, Thomas Peter, Kreupl, Franz, Luyken, Richard Johannes, Hönlein, Wolfgang, Schlösser, Till
• Primary Examiner(s): Prenty, Mark V.
• Application Number:
  US10/275,337
• Publication Number:
  US 20030148562A1
• Time in Patent Office: 650 Days
• Field of Search: 257/213, 257/288, 257/401, 257/410, 257/40
• US Class Current: 257/213
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: G11C 2213/17 Memory cell being a nanowire transistor
• CPC Class Codes: H10K 10/46 Field-effect transistors, e.g. organic thin-film transistors [OTFT] H10K10/43 takes precedence
• CPC Class Codes: H10K 10/701 Organic molecular electronic devices
• CPC Class Codes: H10K 85/221 Carbon nanotubes
• CPC Class Codes: Y10S 977/938 Field effect transistors, FETS, with nanowire- or nanotube-channel region

Abstract

A field-effect transistor that having a nanowire, which forms a source region, a channel region and a drain region of the field-effect transistor, the nanowire being a semiconducting and/or metallically conductive nanowire. The field-effect transistor also has at least one nanotube, which forms a gate region of the field-effect transistor, the nanotube being a semiconducting and/or metallically conductive nanotube. The nanowire and the nanotube are arranged at a distance from one another or set up in such a manner that it is substantially impossible for there to be a tunneling current between the nanowire and the nanotube, and that the conductivity of the channel region of the nanowire can be controlled by means of a field effect as a result of an electric voltage being applied to the nanotube.

Claims

1. A field-effect transistor, comprising:

a nanowire, which forms a source region, a channel region and a drain region of the field-effect transistor, the nanowire being a semiconducting and/or metallically conductive nanowire; and

at least one nanotube, which forms a gate region of the field-effect transistor, the nanotube being a semiconducting and/or metallically conductive nanotube,

the channel region formed by the nanowire and a tip of the nanotube being arranged adjacent to one another and at a distance from one another in such a manner or being set up in such a manner that it is substantially impossible for there to be a tunneling current between the nanowire and the nanotube, and that the conductivity of the channel region of the nanowire can be controlled by means of a field effect as a result of an electric voltage being applied to the nanotube.

2. The field-effect transistor as claimed in claim 1, in which the nanowire is a first nanotube, which forms a source region, a channel region and a drain region of the field-effect transistor, the first nanotube being a semiconducting and/or metallically conductive nanotube, in which the nanotube is formed by a second nanotube, which forms the gate region of the field-effect transistor, the second nanotube being a semi-conducting and/or metallically conductive nanotube, the first nanotube and the second nanotube being arranged at a distance from one another which is such that it is substantially impossible for there to be a tunneling current between the nanotubes and that the conductivity of the channel region of the first nanotube can be controlled by means of a field effect as a result of an electric voltage being applied to the second nanotube.

3. The field-effect transistor as claimed in claim 2, in which the first nanotube or the second nanotube is a carbon nanotube.

4. The field-effect transistor as claimed in one of claims 1 to 3, in which electrically non-conductive gas is introduced between the nanowire and the nanotube.

5. The field-effect transistor as claimed in claim 2 in which the first nanotube and/or the second nanotube has a plurality of walls.

6. The field-effect transistor as claimed in claim 2 in which an insulator layer is applied at least to the channel region of the first nanotube, and

in which the second nanotube is applied to the insulator layer.

7. The field-effect transistor as claimed in claim 6, in which the insulator layer contains an oxide material or a nitride material.

8. The field-effect transistor as claimed in claim 1 in which the nanotube which forms the gate region of the field-effect transistor has three ends, it being possible for an electric voltage to be applied to one end, and the two further ends being arranged in such a manner that, as a result of the applied electric voltage, they can be used to change the conductivitiy of the channel region of the nanowire.

9. The field-effect transistor as claimed in claim 2 in which a third nanotube is provided, which forms a second gate region of the field-effect transistor, the third nanotube being a semiconducting and/or metallically conductive nanotube, and

the nanowire and the third nanotube being arranged at a distance from one another which is such that it is substantially impossible for there to be a tunneling current between the nanowire and the third nanotube, and that the conductivity of the channel region of the nanowire can be controlled by means of a field effect as a result of an electric voltage being applied to the third nanotube.

10. The field-effect transistor as claimed in claim 9 in which the nanotube which forms the gate region of the field-effect transistor and the third nanotube are electrically coupled to one another.

11. The field-effect transistor as claimed in claim 1 in which at least one of the nanotubes includes a multiplicity of nanotubes.

12. The field-effect transistor as claimed in claim 1, in which the at least one nanotube is applied to the nanowire and includes an electrically insulating region and a semiconducting region or a metallically conductive region,

the insulating region of the nanotube being applied to the channel region of the nanowire in such a manner that the insulating region of the nanotube forms an insulator of the field-effect transistor and, that the semiconducting region or the metallically conductive region of the nanotube forms a gate region of the field-effect transistor.

13. The field-effect transistor as claimed in claim 12, in which the nanowire is a silicon nanowire.

14. The field-effect transistor as claimed in claim 12 in which the nanowire is a further nanotube.

15. The field-effect transistor as claimed in claim 14, in which the further nanotube is a further carbon nanotube.

16. The field-effect transistor as claimed in claim 14 or 15, in which the further nanotube includes at least one semiconducting region and at least one metallically conductive region.

17. The field-effect transistor as claimed in claim 16, in which the semiconducting region is arranged between two metallically conductive regions.

18. The field-effect transistor as claimed in claim 12 in which the insulating region of the nanotube is a boron nitride nanotube.

19. The field-effect transistor as claimed in claim 12 in which the semiconducting region or the metallically conductive region of the nanotube is a carbon nanotube.

20. The field-effect transistor as claimed in claim 12 in which at least one of the nanotubes includes a plurality of walls.

21. A field-effect transistor, comprising:

a nanowire, which forms a source region, a channel region and a drain region of the field-effect transistor, the nanowire being a semiconducting and/or metallically conductive nanowire; and

at least one nanotube, which form a gate region of the field-effect transistor, the nanotube being a semiconducting and/or metallically conductive nanotube,

the nanowire and the nanotube being arranged at a distance from one another, at least one further electrically insulating nanotube as a gate insulator arranged concentrically between the nanowire and the nanotube in such a manner or being set up in such a manner that it is substantially impossible for there to be a tunneling current between the nanowire and the nanotube, and that the conductivity of the channel region of the nanowire can be controlled by means of a field effect as a result of an electric voltage being applied to the nanotube.

22. The field-effect transistor as claimed in claim 21, having the nanowire, which forms a source region, a channel region and a drain region of the field-effect transistor,

having the at least one electrically insulating nanotube which is applied to the nanowire and forms the gate insulator of the field-effect transistor, and

having the at least one electrically semiconducting or metallically conductive nanotube which is applied to the insulating nanotube and forms a gate region of the field-effect transistor.

23. The field-effect transistor as claimed in claim 21, in which the electrically insulating nanotube is a boron nitride nanotube.

24. The field-effect transistor as claimed in claim 21, in which the semiconducting or metallically conductive nanotube is a carbon nanotube.