Nanomechanical switches and circuits

• US 6,534,839 B1
• Filed: 11/09/2000
• Issued: 03/18/2003
• Est. Priority Date: 12/23/1999
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Seabaugh, Alan C., Frazier, Gary A.
• Primary Examiner(s): Wilson, Allan R.
• Application Number:
  US09/711,001
• Time in Patent Office: 859 Days
• Field of Search: 200/181, 257/415, 257/421
• US Class Current: 257/421
• 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 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: G11C 23/00 Digital stores characterised by movement of mechanical parts to effect storage, e.g. using balls; Storage elements therefor
• CPC Class Codes: H01H 1/0094 Switches making use of nanoelectromechanical systems [NEMS]
• CPC Class Codes: Y10S 977/708 with distinct switching device

Abstract

A highly miniaturized nanomechanical transistor switch is fabricated using a mechanical cantilever which creates a conductive path between two electrodes in its deflected state. In one embodiment, the cantilever is deflected by an electrostatic attraction arising from a voltage potential between the cantilever and a control electrode. In another embodiment, the cantilever is formed of a material with high magnetic permeability, and is deflected in response to complementary magnetic fields induced in the cantilever and in an adjacent electrode. The nanomechanical switch can be fabricated using well known semiconductor fabrication techniques, although semiconductor materials are not necessary for fabrication. The switch can rely upon physical contact between the cantilever and the adjacent electrode for current flow, or can rely upon sufficient proximity between the cantilever and the adjacent electrode to allow for tunneling current flow.

Claims

1. A nanomechanical switch comprising:

a substrate;

a first electrode formed on the substrate;

a second electrode formed on the substrate;

a third electrode having a cantilever member extending over the first and second electrodes;

a voltage source coupled between the first and third electrodes, wherein the cantilever member has an undeflected state when no bias is applied between the first and third electrodes, and a deflected state when a bias is applied between the first and third electrodes; and

a lubricating layer formed atop of the second electrode, the lubricating layer being adapted to conduct by way of tunneling.

5. The nanomechanical switch of claim 1 in which the lubricating layer is formed of an insulative material.

2. A nanomechanical switch comprising:

a substrate;

a first electrode formed on the substrate;

a second electrode formed on the substrate;

a third electrode having a cantilever member extending over the first and second electrodes; and

a voltage source coupled between the first and third electrodes, wherein the cantilever member has an undeflected state when no bias is applied between the first and third electrodes, and a deflected state when a bias is applied between the first and third electrodes;

wherein the cantilever is above spaced apart from the second electrode by between 10 and 40 angstroms in the undeflected state.

3. A nanomechanical switch comprising:

a substrate;

a first electrode formed on the substrate;

a second electrode formed on the substrate;

a third electrode having a cantilever member extending over the first and second electrodes;

a voltage source coupled between the first and third electrodes, wherein the cantilever member has an undeflected state when no bias is applied between the first and third electrodes, and a deflected state when a bias is applied between the first and third electrodes; and

an oxide feature formed on the substrate, on top of which is formed the third electrode.

4. A nanomechanical switch comprising:

a substrate;

a first electrode formed on the substrate;

a second electrode formed on the substrate;

a third electrode having a cantilever member, 2000 angstroms in length, extending over the first and second electrodes; and

a voltage source coupled between the first and third electrodes, wherein the cantilever member has an undeflected state when no bias is applied between the first and third electrodes, and a deflected state when a bias is applied between the first and third electrodes.