Schottky diode switch and memory units containing the same

• US 8,288,749 B2
• Filed: 04/12/2012
• Issued: 10/16/2012
• Est. Priority Date: 07/13/2009
• Status: Active Grant

• Current Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Original Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Inventors: Kim, Young Pil, Amin, Nurul, Setiadi, Dadi, Vaithyanathan, Venugopalan, Tian, Wei, Jin, Insik
• Primary Examiner(s): Malsawma, Lex
• Application Number:
  US13/445,351
• Publication Number:
  US 20120199936A1
• Time in Patent Office: 187 Days
• Field of Search: 257/2, 257/471, 257/E29.336, 257/E45.002
• US Class Current: 257/2
• CPC Class Codes: G11C 11/161 details concerning the memory cell structure, e.g. the layers of the ferromagnetic memory cell
• CPC Class Codes: G11C 11/1659 Cell access
• CPC Class Codes: G11C 13/0002 using resistive RAM [RRAM] elements
• CPC Class Codes: H01L 21/84 the substrate being other than a semiconductor body, e.g. being an insulating body
• CPC Class Codes: H01L 27/0688 Integrated circuits having a three-dimensional layout
• CPC Class Codes: H01L 27/0814 Diodes only
• CPC Class Codes: H01L 27/101 including resistors or capacitors only
• CPC Class Codes: H01L 27/1021 including diodes only
• CPC Class Codes: H01L 27/1203 the substrate comprising an insulating body on a semiconductor body, e.g. SOI three-dimensional layout H01L27/0688
• CPC Class Codes: H01L 29/66143 Schottky diodes
• CPC Class Codes: H01L 29/66212 Schottky diodes
• CPC Class Codes: H01L 29/872 Schottky diodes
• CPC Class Codes: H10B 53/30 characterised by the memory core region
• CPC Class Codes: H10B 61/10 comprising components having two electrodes, e.g. diodes or MIM elements
• CPC Class Codes: H10B 63/20 comprising selection components having two electrodes, e.g. diodes
• CPC Class Codes: H10N 70/20 Multistable switching devices, e.g. memristors
• CPC Class Codes: H10N 70/231 based on solid-state phase change, e.g. between amorphous and crystalline phases, Ovshinsky effect
• CPC Class Codes: H10N 70/245 the species being metal cations, e.g. programmable metallization cells
• CPC Class Codes: H10N 70/881 Switching materials
• CPC Class Codes: H10N 70/8825 Selenides, e.g. GeSe
• CPC Class Codes: H10N 70/8833 : Binary metal oxides, e.g. TaOx
• CPC Class Codes: H10N 70/8836 : Complex metal oxides, e.g. perovskites, spinels

Abstract

A switching element that includes a first semiconductor layer, the first semiconductor layer having a first portion and a second portion; a second semiconductor layer, the second semiconductor layer having a first portion and a second portion; an insulating layer disposed between the first semiconductor layer and the second semiconductor layer; a first metal contact in contact with the first portion of the first semiconductor layer forming a first junction and in contact with the first portion of the second semiconductor layer forming a second junction; a second metal contact in contact with the second portion of the first semiconductor layer forming a third junction and in contact with the second portion of the second semiconductor layer forming a fourth junction, wherein the first junction and the fourth junction are Schottky contacts, and the second junction and the third junction are ohmic contacts.

Claims

1. A bidirectional switch comprising:

a first semiconductor layer;

a second semiconductor layer;

a first insulating layer disposed between the first semiconductor layer and the second semiconductor layer;

a first metal contact in physical contact with the first semiconductor layer, the second semiconductor layer and the first insulating layer; and

a second metal contact in physical contact with the first semiconductor layer, the second semiconductor layer and the first insulating layer,

wherein the physical contacts between the first metal contact and the first semiconductor layer, the first metal contact and the second semiconductor layer, the second metal contact and the first semiconductor layer, and the second metal contact and the second semiconductor layer are independently either Schottky contacts or ohmic contacts with the proviso that the orientation of the Schottky contacts and the ohmic contacts in the first semiconductor layer are opposite to the orientation of the Schottky contacts and the ohmic contacts in the second semiconductor layer.

2. The bidirectional switch according to claim 1, wherein the physical contact between the first metal contact and the first semiconductor layer and the physical contact between the first metal contact and the second semiconductor layer are not the same.

3. The bidirectional switch according to claim 1, wherein the physical contact between the second metal contact and the first semiconductor layer and the physical contact between the second metal contact and the second semiconductor layer are not the same.

4. The bidirectional switch according to claim 1, wherein the physical contact between the first metal contact and the first semiconductor layer is a Schottky contact;

the physical contact between the first metal contact and the second semiconductor layer is an ohmic contact;

the physical contact between the second metal contact and the first semiconductor layer is an ohmic contact; and

the physical contact between the second metal contact and the second semiconductor layer is a Schottky contact.

5. The bidirectional switch according to claim 1, wherein the physical contact between the first metal contact and the first semiconductor layer is a ohmic contact;

the physical contact between the first metal contact and the second semiconductor layer is a Schottky contact;

the physical contact between the second metal contact and the first semiconductor layer is a Schottky contact; and

the physical contact between the second metal contact and the second semiconductor layer is an ohmic contact.

6. The bidirectional switch according to claim 1 further comprising a second insulating layer, wherein the second insulating layer is adjacent the first semiconductor layer opposite the first insulating layer.

7. The bidirectional switch according to claim 1, wherein the first semiconductor layer and the second semiconductor layer are independently chosen from:

silicon, silicon containing compounds, germanium, germanium containing compounds, aluminum containing compounds, boron containing compounds, gallium containing compounds, indium containing compounds, cadmium containing compounds, zinc containing compounds, lead containing compounds, and tin containing compounds.

8. The bidirectional switch according to claim 1, wherein the first semiconductor layer is crystalline silicon and a portion of the first semiconductor layer in contact with the second metal contact is doped with phosphorus (P), boron (B), or arsenic (As).

9. The bidirectional switch according to claim 1, wherein the second semiconductor layer is crystalline silicon and a portion of the second semiconductor layer in contact with the second metal contact is doped with phosphorus (P), boron (B), or arsenic (As).

10. The bidirectional switch according to claim 1, wherein the portion of the first semiconductor layer in contact with the first metal contact and the portion of the second semiconductor layer in contact with the first metal contact are not heavily doped.

11. A bidirectional switch comprising:

a first semiconductor layer;

a second semiconductor layer;

a first insulating layer disposed between the first semiconductor layer and the second semiconductor layer;

a first metal contact in physical contact with the first semiconductor layer, the second semiconductor layer and the first insulating layer; and

a second metal contact in physical contact with the first semiconductor layer, the second semiconductor layer and the first insulating layer,

wherein the physical contacts between the first metal contact and the first semiconductor layer, the first metal contact and the second semiconductor layer, the second metal contact and the first semiconductor layer, and the second metal contact and the second semiconductor layer are independently either Schottky contacts or ohmic contacts, and wherein the physical contact between the first metal contact and the first semiconductor layer and the physical contact between the first metal contact and the second semiconductor layer are not the same and the physical contact between the second metal contact and the first semiconductor layer and the physical contact between the second metal contact and the second semiconductor layer are not the same.

12. The bidirectional switch according to claim 11, wherein the physical contact between the first metal contact and the first semiconductor layer is a Schottky contact;

the physical contact between the first metal contact and the second semiconductor layer is an ohmic contact;

the physical contact between the second metal contact and the first semiconductor layer is an ohmic contact; and

the physical contact between the second metal contact and the second semiconductor layer is a Schottky contact.

13. The bidirectional switch according to claim 11, wherein the physical contact between the first metal contact and the first semiconductor layer is a ohmic contact;

the physical contact between the first metal contact and the second semiconductor layer is a Schottky contact;

the physical contact between the second metal contact and the first semiconductor layer is a Schottky contact; and

the physical contact between the second metal contact and the second semiconductor layer is an ohmic contact.

14. The bidirectional switch according to claim 11, wherein the first semiconductor layer and the second semiconductor layer are independently chosen from:

silicon, silicon containing compounds, germanium, germanium containing compounds, aluminum containing compounds, boron containing compounds, gallium containing compounds, indium containing compounds, cadmium containing compounds, zinc containing compounds, lead containing compounds, and tin containing compounds.

15. The bidirectional switch according to claim 11, wherein the first semiconductor layer is crystalline silicon and a portion of the first semiconductor layer in contact with the second metal contact is doped with phosphorus (P), boron (B), or arsenic (As).

16. The bidirectional switch according to claim 11, wherein the second semiconductor layer is crystalline silicon and a portion of the second semiconductor layer in contact with the second metal contact is doped with phosphorus (P), boron (B), or arsenic (As).

17. The bidirectional switch according to claim 11, wherein the portion of the first semiconductor layer in contact with the first metal contact and the portion of the second semiconductor layer in contact with the first metal contact are not heavily doped.

18. The bidirectional switch according to claim 11 further comprising a second insulating layer, wherein the second insulating layer is adjacent the first semiconductor layer opposite the first insulating layer.

19. A bidirectional switch comprising:

a first semiconductor layer;

a second semiconductor layer;

a first insulating layer disposed between the first semiconductor layer and the second semiconductor layer;

a first metal contact in physical contact with the first semiconductor layer, the second semiconductor layer and the first insulating layer; and

a second metal contact in physical contact with the first semiconductor layer, the second semiconductor layer and the first insulating layer,

wherein the first semiconductor layer is crystalline silicon and a portion of the first semiconductor layer in contact with the second metal contact is doped with phosphorus (P), boron (B), or arsenic (As), the second semiconductor layer is crystalline silicon and a portion of the second semiconductor layer in contact with the second metal contact is doped with phosphorus (P), boron (B), or arsenic (As), and the portion of the first semiconductor layer in contact with the first metal contact and the portion of the second semiconductor layer in contact with the first metal contact are not heavily doped.