Memory device with active passive layers

• US 20040026714A1
• Filed: 04/15/2003
• Published: 02/12/2004
• Est. Priority Date: 08/13/2001
• Status: Active Grant

• Current Assignee: Spansion LLC (Infineon Technologies AG)
• Original Assignee: Advanced Micro Devices, Inc.
• Inventors: Krieger, Juri H., Yudanov, Nikolai
• Granted Patent: US 6,838,720 B2
• Time in Patent Office: Days
• US Class Current: 257/200
• 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 11/34 using semiconductor devices
• CPC Class Codes: G11C 11/5664 using organic memory material storage elements
• CPC Class Codes: G11C 13/0014 comprising cells based on organic memory material
• CPC Class Codes: G11C 13/0016 comprising polymers
• CPC Class Codes: G11C 2213/11 Metal ion trapping, i.e. using memory material including cavities, pores or spaces in form of tunnels or channels wherein metal ions can be trapped but do not react and form an electro-deposit creating filaments or dendrites
• CPC Class Codes: G11C 2213/12 Non-metal ion trapping, i.e. using memory material trapping non-metal ions given by the electrode or another layer during a write operation, e.g. trapping, doping
• CPC Class Codes: G11C 2213/15 Current-voltage curve
• CPC Class Codes: G11C 2213/56 Structure including two electrodes, a memory active layer and a so called passive or source or reservoir layer which is NOT an electrode, wherein the passive or source or reservoir layer is a source of ions which migrate afterwards in the memory active layer to be only trapped there, to form conductive filaments there or to react with the material of the memory active layer in redox way
• CPC Class Codes: G11C 2213/72 Array wherein the access device being a diode
• CPC Class Codes: G11C 2213/77 Array wherein the memory element being directly connected to the bit lines and word lines without any access device being used
• CPC Class Codes: H10K 19/00 Integrated devices, or assemblies of multiple devices, comprising at least one organic element specially adapted for rectifying, amplifying, oscillating or switching, covered by group H10K10/00
• CPC Class Codes: H10K 85/10 Organic polymers or oligomers
• CPC Class Codes: H10K 85/111 comprising aromatic, heteroaromatic, or aryl chains, e.g. polyaniline, polyphenylene or polyphenylene vinylene
• CPC Class Codes: H10K 85/113 Heteroaromatic compounds comprising sulfur or selene, e.g. polythiophene
• CPC Class Codes: H10K 85/1135 Polyethylene dioxythiophene [PEDOT]; Derivatives thereof
• CPC Class Codes: H10K 85/143 Polyacetylene; Derivatives thereof

Abstract

A memory including memory cells having active and passive layers may store multiple information bits. The active layer may include an organic polymer that has a variable resistance based on the movement of charged species (ions or ions and electrons) between the passive layer and the active layer. The passive layer may be a super-ionic material that has high ion and electron mobility. The active layer may be self-assembled from a monomer in a liquid or gas.

Claims

1. A reversibly programmable memory comprising at least one memory cell, the at least one memory cell comprising:

a first conductive electrode layer;

a passive layer formed over the first electrode layer, the passive layer being a super-ionic material including copper sulfide adapted to reversibly donate and accept charged species, the charged species including ions or ions and electrons;

an active layer formed over the passive layer, the active layer being an organic polymer that has a reversibly variable electrical conductivity upon the introduction and removal of charged species from the passive layer, the electrical conductivity of the organic polymer being variable between three or more states to store multiple information bits, the organic polymer having a relatively lower electrical conductivity when free of charged species and a relatively higher electrical conductivity when charged species are introduced; and

a second conductive electrode layer formed over the active layer;

wherein the passive layer reversibly donates and accepts charged species to and from the active layer when an electrical potential difference is applied between the two electrode layers, and the two electrode layers are used to both program the memory cell to store information and read stored information from the memory cell.

2. The memory of claim 1, wherein the first conductive electrode layer is made of copper.

3. The memory of claim 1, wherein the active layer includes one of polyphenylacetylene (PPA) and polydiphenylacetylene (PDPA) having said reversibly variable electrical conductivity.

4. The memory of claim 1, wherein:

the first conductive electrode layer is made of copper, and

the active layer includes one of polyphenylacetylene (PPA) and polydiphenylacetylene (PDPA) having said reversibly variable electrical conductivity.

5. The memory of claim 1, further comprising:

a barrier layer including a material that impedes spontaneous movement of charged species between the active layer and the passive layer when an electrical potential difference is not applied between the two electrode layers.

6. The memory of claim 5, wherein the barrier layer is positioned between the active layer and the passive layer.

7. The memory of claim 1, wherein the active layer is about 50 to about 1000 Angstroms thick.

8. The memory of claim 1, wherein the passive layer is about 20 to about 100 Angstroms thick.

9. The memory of claim 1, wherein the memory cell includes only one active layer and only one passive layer between the first and second conductive electrode layers.

10. A reversibly programmable memory comprising at least one memory cell, the at least one memory cell comprising:

a first conductive electrode layer;

a passive layer formed over the first electrode layer, the passive layer being a superionic material adapted to reversibly donate and accept charged species, the charged species including ions or ions and electrons;

an active layer formed over the passive layer, the active layer being an organic polymer that has a reversibly variable electrical conductivity upon the introduction and removal of charged species from the passive layer, the electrical conductivity of the organic polymer being variable between three or more states to store multiple information bits, the organic polymer having a relatively lower electrical conductivity when free of charged species and a relatively higher electrical conductivity when charged species are introduced; and

a second conductive electrode layer formed over the active layer;

wherein the passive layer reversibly donates and accepts charged species to and from the active layer when an electrical potential difference is applied between the two electrode layers, and the two electrode layers are used to both program the memory cell to store information and read stored information from the memory cell.

11. The memory of claim 10, wherein the passive layer includes copper sulfide.

12. The memory of claim 10, wherein the first conductive electrode layer is made of copper.

13. The memory of claim 10, wherein the active layer includes one of polyphenylacetylene (PPA) and polydiphenylacetylene (PDPA) having said reversibly variable electrical conductivity.

14. The memory of claim 10, wherein:

the first conductive electrode layer is made of copper,

the passive layer includes copper sulfide, and

the active layer includes one of polyphenylacetylene (PPA) and polydiphenylacetylene (PDPA) having said reversibly variable electrical conductivity.

15. The memory of claim 10, further comprising:

a barrier layer including a material that impedes spontaneous movement of charged species between the active layer and the passive layer when an electrical potential difference is not applied between the two electrode layers.

16. The memory of claim 15, wherein the barrier layer is positioned between the active layer and the passive layer.

17. The memory of claim 10, wherein the active layer is about 50 to about 1000 Angstroms thick.

18. The memory of claim 10, wherein the passive layer is about 20 to about 100 Angstroms thick.

19. The memory of claim 10, wherein the memory cell includes only one active layer and only one passive layer between the first and second conductive electrode layers.