Nanoelectronic devices and circuits

• US 20040149679A1
• Filed: 03/26/2004
• Published: 08/05/2004
• Est. Priority Date: 04/20/2001
• Status: Active Grant

• Current Assignee: PragmatIC Printing Ltd.
• Original Assignee: Nano Eprint Limited
• Inventors: Song, Aimin, Omling, Par
• Granted Patent: US 7,224,026 B2
• Time in Patent Office: Days
• US Class Current: 216/13
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: H01L 29/66075 of devices having semiconductor bodies comprising group 14 or group 13/15 materials comprising semiconducting carbon H01L29/66015; comprising crystalline silicon carbide H01L29/66053
• CPC Class Codes: H01L 29/66204 Diodes
• CPC Class Codes: H01L 29/6631 with an active layer made of a group 13/15 material
• CPC Class Codes: H01L 29/66469 with one- or zero-dimensional channel, e.g. quantum wire field-effect transistors, in-plane gate transistors [IPG], single electron transistors [SET], Coulomb blockade transistors, striped channel transistors
• CPC Class Codes: H01L 29/7393 Insulated gate bipolar mode transistors, i.e. IGBT; IGT; COMFET
• CPC Class Codes: H01L 29/772 Field effect transistors
• CPC Class Codes: H01L 29/775 with one dimensional charge carrier gas channel, e.g. quantum wire FET
• CPC Class Codes: H01L 29/861 Diodes

Abstract

Diode devices with superior and pre-settable characteristics and of nanometric dimensions, comprise etched insulative lines (8, 16, 18) in a conductive substrate to define between the lines charge carrier flow paths, formed as elongate channels (20) at least 100 nm long and less than 100 nm wide. The current-voltage characteristic of the diode devices are similar to a conventional diode, but both the threshold voltage (from 0V to a few volts) and the current level (from nA to μA) can be tuned by orders of magnitude by changing the device geometry. Standard silicon wafers can be used as substrates. A full family of logic gates, such as OR, AND, and NOT, can be constructed based on this device solely by simply etching insulative lines in the substrate.

Claims

1. An electronic circuit component comprising a substrate supporting mobile charge carriers, insulative features formed on the substrate surface to define first and second substrate areas on either side of the insulative features, the insulative features including first and second regions which are positioned close to one another but spaced apart so as to provide an elongate channel, which provides a charge carrier flow path in the substrate from the first area to the second area, and

wherein said elongate channel is dimensioned and arranged such that the parameters of the charge carrier flow path are dependent on a potential difference between said first and second areas.

2. A component according to claim 1, wherein the circuit component comprises a diode.

3. A component according to claims 1 or 2, wherein the length of the elongate channel is at least about 100 nanometres.

4. A component according to any preceding claim, wherein the width of the elongate channel is less than 500 nm, preferably less than 100 nanometres, and preferably about 30 to 50 nanometres.

5. A component according to any preceding claim, wherein the insulative features are defined by first insulative lines separating said first and second substrate areas, and second insulative lines extending at an angle to the first insulative lines and defining said elongate channel.

6. A component according to any preceding claim wherein the elongate channel extends into only one of the first and second substrate areas so that said first and second regions are exposed to a voltage existing in the one area.

7. A full wave rectifier circuit, wherein a substrate is divided by insulative lines into at least four areas each having a respective electrical terminal, and elongate channels are selectively provided in said insulative lines between said four areas in order to create diodes, each diode being as claimed in claim 2, for providing a full wave rectification action.

8. An OR gate circuit, wherein a substrate is divided into at least three regions by insulative lines, a first region providing a first input terminal, a second region providing a second input terminal, and a third region providing an output terminal;

a first elongate channels is provided between said first region and said third region, a second elongate channel is provided between said second region and said third region,

each channel providing a diode according to claim 2,

whereby to enable current flow between the regions upon application of appropriate voltages to the input terminals, whereby to obtain at the output terminal an output voltage reflecting an OR characteristic.

9. An AND gate circuit, wherein a substrate is divided into at least first, second and third regions by insulative lines, a first region providing a first input terminal, a second region providing a second input terminal, and a third region providing an output terminal;

and a first elongate channels is provided between the first region and the third region, and a second elongate channel is provided between the second region and the third region, each channel providing a diode according to claim 2;

whereby to enable current flow between the regions upon application of appropriate voltages to the first and second inputs, whereby to obtain at the output an output voltage reflecting an AND characteristic.

10. A circuit according to claim 9, including a fourth substrate region serving as a voltage rail and connected to said third region by an elongate channel providing a component according to claim 1 and serving as a resistor.

11. A component according to claim 1 or 2, wherein the elongate channel is such that a negative differential resistive characteristic is provided.

12. An oscillator circuit, including one or more reactive components, and a component according to claim 11.

13. A component according to claim 2 formed as a photodiode, wherein the dimensions of said channel are such as to create a region wherein avalanche breakdown occurs upon application of voltage such as to generate light.

14. A matrix array for light emission, comprising row and column address lines, wherein each element of the matrix is a photodiode according to claim 13.

15. A component according to claim 2, arranged such as to generate a detectable current when exposed to light or to a molecular species in solution.

16. A matrix array for light detection, comprising row and column address lines, wherein each element of the matrix is a component according to claim 15.