Scaled nanotube electrode for low power multistage atomic switch

• US 10,468,593 B1
• Filed: 04/11/2018
• Issued: 11/05/2019
• Est. Priority Date: 04/11/2018
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Cao, Qing, Tang, Jianshi, Li, Ning
• Primary Examiner(s): Gebremariam, Samuel A
• Application Number:
  US15/950,754
• Publication Number:
  US 20190319184A1
• Time in Patent Office: 573 Days
• CPC Class Codes: H10N 70/023 by chemical vapor deposition, e.g. MOCVD, ALD
• CPC Class Codes: H10N 70/026 by physical vapor deposition, e.g. sputtering
• CPC Class Codes: H10N 70/046 by diffusion, e.g. photo-dissolution
• CPC Class Codes: H10N 70/066 by filling of openings, e.g. damascene method
• 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 70/841 Electrodes
• CPC Class Codes: H10N 70/8416 adapted for supplying ionic species
• CPC Class Codes: H10N 70/8822 Sulfides, e.g. CuS
• CPC Class Codes: H10N 70/8825 Selenides, e.g. GeSe
• CPC Class Codes: H10N 70/8833 Binary metal oxides, e.g. TaOx

Abstract

A method of forming a memory device that includes depositing a first dielectric material within a trench of composed of a second dielectric material; positioning a nanotube within the trench using chemical recognition to the first dielectric material; depositing a dielectric for cation transportation within the trench on the nanotube; and forming a second electrode on the dielectric for cation transportation, wherein the second electrode is composed of a metal.

Claims

1. A method of forming a memory device comprising:

positioning a carbon nanotube within a trench of an oxide containing material;

patterning the trench to provide a via to the carbon nanotube, wherein the via to the carbon nanotubes defines a memory cell;

depositing a dielectric for cation transportation within the trench on the carbon nanotube; and

forming an electrode on the dielectric for cation transportation, wherein the electrode is composed of a metal.

2. The method of claim 1, wherein the carbon nanotube is a single wall carbon nanotube (SWCNT) having a diameter D1 ranging from 1 nm to 2 nm, and a length that ranges from about 0.5 nanometers to about 10 microns.

3. The method of claim 1, wherein the dielectric for cation transportation has a composition selected from the group consisting of Ge_xSe_1-x, Ge_xS_1-x, Cu₂S, CuO, Ag₂S, TiO₂, ZrO₂, Ta₂O₅, and SiO₂.

4. The method of claim 1, wherein the electrode is of said metal having a composition selected from the group consisting of silver (Ag), copper (Cu), aluminum (Al), zinc (Zn) and combinations thereof.

5. A method of forming a memory device comprising:

depositing a second dielectric material within a trench of composed of a first dielectric material;

positioning a nanotube within the trench using chemical recognition to the trench dielectric material;

depositing a dielectric for cation transportation within the trench on the nanotube; and

forming an electrode on the dielectric for cation transportation, wherein the electrode is composed of a metal.

6. The method of claim 5, wherein the second dielectric material comprises a hafnium including oxide.

7. The method of claim 5, wherein the first dielectric material comprises a silicon including oxide.

8. The method of claim 5, wherein said chemical recognition comprises forming a surface monolayer on the first dielectric material and applying a surfactant to the nanotube, wherein electrostatic force resulting from ion exchange between the surface monolayer and the surfactant aligns the nanotube within the trench.

9. The method of claim 8, wherein the surface monolayer is formed from 4-(N-hydroxycarboxamido)-I-methylpyridinium iodide (NMPI).

10. The method of claim 8, wherein surface monolayer includes a hydroxamic acid end group that self assembles on the second dielectric material.

11. The method of claim 9, wherein the surfactant on the nanotube is provided by sodium dodecyl sulphate (SDS).

12. The method of claim 5, wherein the nanotube is a single wall carbon nanotube (SWCNT) having a diameter D1 ranging from 1 nm to 2 nm.

13. The method of claim 5, wherein the nanotube has a length that ranges from about 0.5 nanometers to about 10 microns.

14. The method of claim 5, wherein the dielectric for cation transportation has a composition selected from the group consisting of Ge_xSe_1-x, Ge_xS_1-x, Cu₂S, CuO, Ag₂S, TiO₂, ZrO₂, Ta₂O₅, and SiO₂.

15. The method of claim 5, wherein the electrode is of said metal having a composition selected from the group consisting of silver (Ag), copper (Cu), aluminum (Al), zinc (Zn) and combinations thereof.