Electronic device with electrode and its manufacture

• US 20030080363A1
• Filed: 02/19/2002
• Published: 05/01/2003
• Est. Priority Date: 10/26/2001
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Kondo, Masao, Kurasawa, Masaki, Maruyama, Kenji
• Granted Patent: US 6,744,085 B2
• Time in Patent Office: Days
• US Class Current: 257/295
• CPC Class Codes: H01L 28/55 with a dielectric comprising a perovskite structure material
• CPC Class Codes: H01L 28/56 the dielectric comprising two or more layers, e.g. comprising buffer layers, seed layers, gradient layers
• CPC Class Codes: H01L 28/60 Electrodes
• CPC Class Codes: H10B 53/00 Ferroelectric RAM [FeRAM] devices comprising ferroelectric memory capacitors
• CPC Class Codes: H10B 53/30 characterised by the memory core region

Abstract

A method of manufacturing an electronic device includes the steps of: (a) preparing a (001) oriented ReO₃ layer; and (b) forming a (001) oriented oxide ferroelectric layer having a perovskite structure on the ReO₃ layer. Preferably, the step (a) includes the steps of: (a-1) preparing a (001) oriented MgO layer; and (a-2) forming a (001) oriented ReO₃ layer on the MgO layer. An electronic device capable of obtaining a ferroelectric layer of a large polarization and a method of manufacturing the same are provided.

Claims

1. An electronic device comprising:

a ReO₃ layer having a (001) orientation; and

an oxide ferroelectric layer having a perovskite structure, said oxide ferroelectric layer being formed on said ReO₃ layer and having a (001) orientation.

2. The electronic device according to claim 1, further comprising:

a MgO layer having a (001) orientation, wherein said ReO₃ layer is formed on said MgO layer.

3. The electronic device according to claim 2, further comprising:

an amorphous layer, wherein said MgO layer is formed on said amorphous layer.

4. The electronic device according to claim 3, further comprising:

an upper electrode formed on said oxide ferroelectric layer.

5. The electronic device according to claim 4,

wherein said amorphous layer is formed of an insulating layer, which is formed to cover a semiconductor element formed on a semiconductor substrate, and

a conductive plug is provided to electrically connect said semiconductor element, said conductive plug penetrating through said insulating layer.

6. The electronic device according to claim 5, wherein said ReO₃ layer is formed on said insulating layer and over said conductive plug.

7. The electronic device according to claim 5, further comprising:

an interlayer insulating layer covering said upper electrode;

a plurality of apertures penetrating through said interlayer insulating layer and exposing said conductive plug and said upper electrode; and

a local wiring connecting said conductive plug and said upper electrode via said apertures.

8. The electronic device according to claim 2, wherein said MgO layer is a single crystal MgO layer having a (001) plane.

9. The electronic device according to claim 1, wherein said ReO₃ layer is added with metal other than Re.

10. The electronic device according to claim 4, wherein said upper electrode is formed of an IrO₂ layer, or a stack of an IrO₂ layer and a SrRuO₃ layer.

11. A method of manufacturing an electronic device, comprising the steps of:

(a) preparing a ReO₃ layer having a (001) orientation; and

(b) forming an oxide ferroelectric layer having a perovskite structure and a (001) orientation, on said ReO₃ layer.

12. The method of manufacturing an electronic device according to claim 11, wherein said step(a) deposits said ReO₃ layer on a single crystal MgO layer having the (001) orientation.

13. The method of manufacturing an electronic device according to claim 11, wherein said step (a) includes the steps of:

(a-1) preparing a MgO layer having a (001) orientation; and

(a-2) forming said ReO₃ layer having a (001) orientation on said MgO layer.

14. The method of manufacturing an electronic device according to claim 13, wherein said step (a-1) includes the steps of:

(a-1-1) preparing an amorphous layer; and

(a-1-2) forming said MgO layer having a (001) orientation on said amorphous layer.

15. The method of manufacturing an electronic device according to claim 14, wherein at least one of said steps (a-1-2), (a-2) and (b) is done by metalorganic chemical vapor deposition (MOCVD).

16. The method of manufacturing an electronic device according to claim 15, wherein all of said steps (a-1-2), (a-2) and (b) are done by MOCVD.

17. The method of manufacturing an electronic device according to claim 15, wherein said MOCVD is executed at a substrate temperature of 620°

C. or lower.

18. The method of manufacturing an electronic device according to claim 15, wherein said MOCVD uses, as organometal raw material, a dipivaloilmethanate (DPM) compound of metal or an iso-proxy (i-PrO) compound of metal.

19. The method of manufacturing an electronic device according to claim 14, wherein at least one of said steps (a-1-2), (a-2) and (b) is done by sputtering.

20. The method of manufacturing an electronic device according to claim 11, further comprising the step of:

(c) forming at least one upper electrode layer on said oxide ferroelectric layer.