Asymmetric barrier diode

• US 8,178,864 B2
• Filed: 11/18/2008
• Issued: 05/15/2012
• Est. Priority Date: 11/18/2008
• Status: Expired due to Fees

• Current Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Original Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Inventors: Jin, Insik, Tian, Wei, Vaithyanathan, Venugopalan, Bedoya, Cedric, Siegert, Markus
• Primary Examiner(s): Jackson, Jr., Jerome
• Assistant Examiner(s): SPALLA, DAVID C
• Application Number:
  US12/272,912
• Publication Number:
  US 20100123210A1
• Time in Patent Office: 1,274 Days
• Field of Search: 257/109, 257/487, 257/485, 257/E27.051, 257/E29.327, 257/E29.338, 257/E29.339
• US Class Current: 257/30
• CPC Class Codes: H10N 70/00 Solid-state devices having no potential barriers, and specially adapted for rectifying, amplifying, oscillating or switching integrated devices or assemblies of multiple devices H10N79/00

Abstract

A diode having a reference voltage electrode, a variable voltage electrode, and a diode material between the electrodes. The diode material is formed of at least one high-K dielectric material and has an asymmetric energy barrier between the reference voltage electrode and the variable voltage electrode, with the energy barrier having a relatively maximum energy barrier level proximate the reference voltage electrode and a minimum energy barrier level proximate the variable voltage electrode.

Claims

1. A diode comprising:

a reference voltage electrode;

a variable voltage electrode; and

a diode material dispersed between the reference voltage electrode and the variable voltage electrode, the diode material comprising at least three layers of high-K dielectric material and having an asymmetric energy barrier between the reference voltage electrode and the variable voltage electrode, the energy barrier having a relatively maximum energy barrier level located proximate the reference voltage electrode and a minimum energy barrier level located proximate the variable voltage electrode, the at least three layers positioned with the high-K dielectric material having the highest conduction band offset located proximate the reference voltage electrode and the high-k dielectric material having the lowest conduction band offset located proximate the variable voltage electrode.

2. The diode of claim 1 wherein the high-K dielectric material is least one of Al₂O₃, HfO₂, LaScO₃, LaAlO₃, Y₂O₃, ZrO₂, La₂O₃, SrTiO₃, Ta₂O₅, and Si₃N₄.

3. The diode of claim 1 wherein the high-K dielectric material having the highest conduction band offset is Al₂O₃.

4. The diode of claim 1 wherein the high-K dielectric material having the lowest conduction band offset is Ta₂O₅.

5. The diode of claim 1 comprising at least four layers of high-K dielectric material, the at least four layers positioned to provide a stepped potential energy profile with the high-K dielectric material having the highest conduction band offset located proximate the reference voltage electrode and the high-k dielectric material having the lowest conduction band offset located proximate the variable voltage electrode.

6. The diode of claim 5 wherein the high-K dielectric material having the highest conduction band offset is Al₂O₃.

7. The diode of claim 5 wherein the high-K dielectric material having the lowest conduction band offset is Ta₂O₅.

15. The diode of claim 1, wherein each of the at least three layers has a thickness of about 20 Angstroms or less.

16. The diode of claim 1, wherein each of the at least three layers has a thickness of about 10 Angstroms or less.

17. The diode of claim 5, wherein each of the at least four layers has a thickness of about 20 Angstroms or less.

18. The diode of claim 5, wherein one layer has a thickness of about 20 Angstroms and the other layers have a thickness of about 10 Angstroms.

19. The diode of claim 5, wherein each of the at least four layers has a thickness of about 10 Angstroms or less.

8. A diode comprising:

a reference voltage electrode;

a variable voltage electrode; and

a diode material dispersed between the reference voltage electrode and the variable voltage electrode, the diode material comprising a compositionally graded layer consisting of one high-K dielectric material oxidized at varying levels and having an asymmetric energy barrier between the reference voltage electrode and the variable voltage electrode, the energy barrier having a relatively maximum energy barrier level proximate the reference voltage electrode and a minimum energy barrier level proximate the variable voltage electrode.

9. The diode of claim 8 wherein the diode material is least one of Al₂O₃, HfO₂, LaScO₃, LaAlO₃, Y₂O₃, ZrO₂, La₂O₃, SrTiO₃, Ta₂O₅, and Si₃N₄.

10. An element comprising:

a reference voltage electrode;

a variable voltage electrode; and

a barrier layer between the reference voltage electrode and the variable voltage electrode, the barrier layer comprising an Al₂O₃ layer and at least two additional high-K dielectric material layers, with the Al₂O₃ and the high-K dielectric materials each having a conduction band offset, with the Al₂O₃ and the high-k dielectric materials positioned to have a stepped potential energy profile with a maximum at the reference voltage electrode and a minimum at the variable voltage electrode.

11. The element of claim 10 wherein the at least two high-K dielectric materials are selected from the group consisting of HfO₂, LaScO₃, LaAlO₃, Y₂O₃, ZrO₂, La₂O₃, SrTiO₃, Ta₂O₅, and Si₃N₄.

12. The element of claim 11 further comprising a third high-K dielectric material, the third high-K dielectric material being at least one of HfO₂, LaScO₃, LaAlO₃, Y₂O₃, ZrO₂, La₂O₃, SrTiO₃, Ta₂O₅, and Si₃N₄, with the Al₂O₃ and the high-K dielectric materials positioned to have a stepped potential energy profile.

13. The element of claim 12 wherein each of the layers has a thickness of about 20 Angstroms or less.

14. The element of claim 13 wherein one layer has a thickness of about 20 Angstroms and the other layers have a thickness of about 10 Angstroms.