Device having a state dependent upon the state of particles dispersed in a carrier

• US 20040085797A1
• Filed: 11/01/2002
• Published: 05/06/2004
• Est. Priority Date: 11/01/2002
• Status: Active Grant

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Jackson, Warren, Mei, Ping
• Granted Patent: US 6,807,079 B2
• Time in Patent Office: Days
• US Class Current: 365/96
• CPC Class Codes: G11C 16/02 electrically programmable
• CPC Class Codes: G11C 17/16 using electrically-fusible links
• CPC Class Codes: H01L 23/5252 comprising anti-fuses, i.e. connections having their state changed from non-conductive to conductive
• CPC Class Codes: H01L 23/5256 comprising fuses, i.e. connections having their state changed from conductive to non-conductive
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H10B 63/80 Arrangements comprising multiple bistable or multi-stable switching components of the same type on a plane parallel to the substrate, e.g. cross-point arrays
• CPC Class Codes: H10N 70/24 based on migration or redistribution of ionic species, e.g. anions, vacancies
• CPC Class Codes: H10N 70/245 the species being metal cations, e.g. programmable metallization cells
• CPC Class Codes: H10N 70/826 adapted for essentially vertical current flow, e.g. sandwich or pillar type devices
• CPC Class Codes: H10N 70/881 Switching materials

Abstract

A device that includes a layer of material having particles dispersed therein, a first electrode on a first surface of the layer, and a second electrode on a second surface of the layer opposite the first surface. A state of the particles is changed when a prescribed voltage is applied across the first and second electrodes.

Claims

6. A device including:

a layer of material having particles dispersed therein;

a first electrode disposed on a first surface of the layer; and

,

a second electrode disposed on a second surface of the layer opposite the first surface;

wherein the particles have an initial state in which they do not form a conductive path between the first and second electrodes, and

wherein the particles agglomerate and form a conductive path between the first and second electrodes in response to a prescribed voltage being applied across the first and second electrodes.

7. The device as set forth in claim 6, wherein the particles comprise electrically conductive nanoparticles.

8. The device as set forth in claim 6, wherein the particles diffuse due to migration in response to application of the prescribed voltage, resulting in an increased density of particles in a region of the layer between the first and second electrodes, and a decreased density of particles in a second region of the layer outside of the first region.

9. The device as set forth in claim 6, wherein the thickness of the layer and dispersion density of the particles are such that the probability of the formation of the conductive path between the first and second electrodes in response to application of the prescribed voltage is substantially 100%.

10. The device as set forth in claim 6, wherein the thickness of the layer is greater than a percolation threshold of the layer.

11. The device as set forth in claim 6, wherein the particles are comprised of a diffusive metal.

12. The device as set forth in claim 6, wherein the material is flexible.

13. The device as set forth in claim 6, wherein the device is operable as a one-time programmable switch.

14. A write-once memory cell including the device as set forth in claim 6.

15. A device comprising:

a layer of material having particles dispersed therein;

a first electrode disposed on a first surface of the layer; and

a second electrode disposed on a second surface of the layer opposite the first surface;

wherein the particles have an initial state in which they form a conductive path between the first and second electrodes, and

wherein further, the conductive path is broken in response to a prescribed voltage being applied across the first and second electrodes.

16. The device as set forth in claim 15, wherein the particles comprise electrically conductive nanoparticles.

17. The device as set forth in claim 15, wherein:

the conductive path comprises a fuse composed of agglomerated particles; and

the fuse is blown in response to application of the prescribed voltage due to a current flowing through the fuse.

18. The device as set forth in claim 15, wherein the particles are comprised of an oxidizing metal.

19. The device as set forth in claim 18, wherein the material contains an oxidant for the oxidizing metal.

20. The device as set forth in claim 15, wherein the layer material is flexible.

21. The device as set forth in claim 15, wherein the device is operable as a one-time programmable switch.

22. A memory cell including the device as set forth in claim 15.

23. A device comprising:

a layer of material having dipole particles dispersed therein;

a first electrode disposed on a first surface of the layer; and

,

a second electrode disposed on a second surface of the layer;

wherein the dipole particles are initially aligned in a first orientation, and are aligned in a second orientation when a prescribed voltage is applied, and

wherein the dipole particles form a conductive path between the first and second electrodes when aligned in the second orientation, and do not form a conductive path between the first and second electrodes when aligned in the first orientation.

24. The device as set forth in claim 23, wherein the first orientation comprises a horizontal orientation with respect to upper and lower surfaces of the layer.

25. The device as set forth in claim 23, wherein the material comprises a viscoelastic material.

26. The device as set forth in claim 23, wherein the dipole particles comprise dipole nanoparticles.

27. The device as set forth in claim 23, wherein device comprises a one-time programmable switch.

28. A write-once memory cell including the device as set forth in claim 23.

29. A device comprising:

a gate electrode;

a gate dielectric layer beneath the gate electrode, the gate dielectric layer comprising a layer of material having particles dispersed therein;

a first electrically conductive element adjacent to a first side of the gate electrode; and

a second electrically conductive element adjacent to a second side of the gate electrode opposite the first side;

wherein the particles migrate in response to a prescribed voltage being applied to the gate electrode in such a manner as to alter current-voltage characteristics of the device.

1. A device comprising:

a layer of material having particles dispersed therein;

a first electrode on a first surface of the layer; and

a second electrode on a second surface of the layer opposite the first surface;

a state of the particles being changed when a prescribed voltage is applied across the first and second electrodes.

3. The device as set forth in claim 1, wherein:

the particles are made of an oxidizing metal that form a conductive path between the electrodes; and

the voltage causes the particles to oxidize and become non-conductive.

4. The device as set forth in claim 1, wherein:

the particles are made of a diffusive metal that forms a conductive path between the electrodes; and

the voltage causes the particles to disperse, thereby breaking the conductive path and causing the device to go from a conductive state to a non-conductive state.

5. The device as set forth in claim 1, wherein:

the particles are dipoles; and

the voltage causes the dipoles to rotate, the rotation affecting conductivity between the first and second electrodes.

30. The device as set forth in claim 29, wherein the particles are nanoparticles.

31. A transistor including the device as set forth in claim 29, wherein the first and second electrically conductive elements comprise source and drain electrodes.

32. The device as set forth in claim 31, wherein changes in the current-voltage characteristics of the transistor result in detectable changes in a gate capacitance of the transistor.

33. The device as set forth in claim 32, wherein the detectable changes in gate capacitance result in detectable changes in source-drain current.

34. The device as set forth in claim 29, wherein the device can be programmed to store a first logic value by applying the prescribed voltage to both the gate electrode and the first electrically conductive element while holding the second electrically conductive element at a reference potential, and wherein the device can be programmed to store a second value by applying the prescribed voltage to both the gate electrode and the second electrically conductive element while holding the first electrically conductive element at the reference potential.

35. The device as set forth in claim 29, wherein the device is an anti-fuse device.

36. The device as set forth in claim 29, wherein the device is a fuse device.

32-1. A memory cell including the device as set forth in claim 29.

37. A memory device comprising:

an array of memory cells, each of the memory cells comprising;

a gate electrode;

a gate dielectric layer beneath the gate electrode, the gate dielectric layer comprising a layer of material having particles dispersed therein;

a first electrically conductive element adjacent to a first side of the gate electrode; and

a second electrically conductive element adjacent to a second side of the gate electrode opposite the first side;

a state of the particles being changed when a prescribed voltage is applied across the first and second electrodes, to thereby write data into the memory cell, wherein a change in the state of the particles alters current-voltage characteristics of the memory cell.

38. The device of claim 37, further comprising read circuitry that detects changes in the current-voltage characteristics of the memory cells.

39. The memory device as set forth in claim 37, wherein, for each memory cell:

the particles are made of a diffusive metal dispersed in the material between the first and second electrodes; and

the voltage causes the particles to agglomerate, thereby causing the memory cell to go from a non-conductive state to a conductive state, whereby the memory cell functions as a fuse.

40. The memory device as set forth in claim 39, wherein, for each memory cell:

the particles are made of an oxidizing metal that form a conductive path between the electrodes; and

the voltage causes the particles to oxidize and become non-conductive, whereby the memory cell functions as an anti-fuse.

41. The memory device as set forth in claim 39, wherein for each memory cell:

the particles are made of a diffusive metal that forms a conductive path between the electrodes; and

the voltage causes the particles to disperse, thereby breaking the conductive path and causing the memory cell to go from a conductive state to a non-conductive state, whereby the memory cell functions as an anti-fuse.

42. The memory device as set forth in claim 39, wherein for each memory cell:

the particles are dipoles; and

the voltage causes the dipoles to rotate, the rotation affecting conductivity of the memory cell.

43. A data storage device comprising a plurality of switches, each switch including a layer of material having particles dispersed therein, a first electrode on a first surface of the layer, and a second electrode on a second surface of the layer opposite the first surface;

a state of the particles of a selected switch being changed when a prescribed voltage is applied across the first and second electrodes of the selected switch.

2. The device as set forth in claim 1, wherein:

the particles are made of a diffusive metal dispersed in the material between the first and second electrodes; and

the voltage causes the particles to agglomerate, thereby causing the device to go from a non-conductive state to a conductive state.

44. The device as set forth in claim 43, wherein the particles are made of a diffusive metal;

and the prescribed voltage causes the particles to go from a non-conductive state to a conductive state.

45. The device as set forth in claim 43, wherein the particles are made of an oxidizing metal;

and wherein the prescribed voltage causes the particles to oxidize and become non-conductive.

46. The device as set forth in claim 43, wherein the particles are made of a diffusive metal;

and wherein the prescribed voltage causes the particles to go from a conductive state to a non-conductive state.

46-2. The device as set forth in claim 43, wherein the particles are dipoles;

and wherein the prescribed voltage causes the dipoles to rotate, the rotation affecting conductivity of the selected switch.