Capacitor structure

Patent metadata

Field	Value
Publication number	US-11088240-B2
Application number	US-201916445011-A
Country	US
Kind code	B2
Filing date	Jun 18, 2019
Priority date	Oct 17, 2018
Publication date	Aug 10, 2021
Grant date	Aug 10, 2021

Abstract

A capacitor includes a lower electrode including a first metal material and having a first crystal size in a range of a few nanometers, a dielectric layer covering the lower electrode and having a second crystal size that is a value of a crystal expansion ratio times the first crystal size and an upper electrode including a second metal material and covering the dielectric layer. The upper electrode has a third crystal size smaller than the second crystal size.

First claim

What is claimed is:

1. A capacitor comprising:
a lower electrode comprising a first metal material and having a crystal size of a few nanometers;
a dielectric layer comprising dielectric material covering the first metal material, the dielectric material comprising merged crystals that each include a plurality of crystals, the merged crystals having a crystal size that is a value of a crystal expansion ratio times the crystal size of the first metal material, wherein the crystal expansion ratio is an integer; and
an upper electrode covering the dielectric layer, the upper electrode comprising a second metal material and having a crystal size smaller than the crystal size of the dielectric material.

2. The capacitor of claim 1 , wherein the dielectric layer includes at least one of zirconium oxide (ZrO2), hafnium oxide (HfO2), tantalum oxide (Ta2O3), aluminum oxide (Al2O3), aluminum nitride (AlN), boron nitride (BN), zirconium nitride (Zr3N4), hafnium nitride (Hf3N4), and lanthanides.

3. The capacitor of claim 1 , wherein the crystal size of the lower electrode is a minimal crystal size of metal material constituting the lower electrode.

4. The capacitor of claim 3 , wherein the first metal material of the lower electrode has a <111> crystallographic direction.

5. The capacitor of claim 3 , wherein the crystal expansion ratio is determined by process conditions of a heat treatment for forming the dielectric layer.

6. The capacitor of claim 3 , wherein the lower electrode comprises at least one of titanium nitride (TiN) and niobium nitride (NbN).

7. The capacitor of claim 6 , wherein the upper electrode comprises at least one of titanium nitride (TiN) and niobium nitride (NbN).

8. The capacitor of claim 5 , wherein the integer is in a range of 5 to 20.

9. The capacitor of claim 8 , wherein the crystal size of the lower electrode is in a range of 3 nm to 10 nm and the crystal size of the dielectric layer is in a range of 15 nm to 200 nm.

10. A capacitor comprising:
a lower electrode comprising a layer of metal material having a crystal size in a range of 3-10 nanometers;
a dielectric covering the layer of metal material of the lower electrode and comprising a layer of dielectric material, the dielectric material comprising merged crystals that each include a plurality of crystals, the merged crystals having a crystal size that is 5-20 times the crystal size of the layer of metal material of the lower electrode; and
an upper electrode covering the dielectric, the upper electrode comprising a layer of metal material having a crystal size smaller than the crystal size of the layer of dielectric material.

11. The capacitor of claim 10 , wherein the layer of dielectric material is disposed directly on the layer of metal material of the lower electrode,
the layer of metal material of the lower electrode is a layer of titanium nitride (TiN) or a layer of niobium nitride (NbN), and
the layer of dielectric material is selected from the group consisting of zirconium oxide (ZrO 2 ), hafnium oxide (HfO 2 ), tantalum oxide (Ta 2 O 3 ), aluminum oxide (Al 2 O 3 ), aluminum nitride (AlN), boron nitride (BN), zirconium nitride (Zr 3 N 4 ), hafnium nitride (Hf 3 N 4 ), and lanthanides.

12. The capacitor of claim 10 , wherein the layer of dielectric material is disposed directly on the layer of metal material of the lower electrode, and
the layer of metal material of the lower electrode has a <111> crystallographic direction.

13. The capacitor of claim 10 , wherein the crystal size of the merged crystals is an integer number of times larger than the crystal size of the layer of metal material of the lower electrode.

14. The capacitor of claim 10 , wherein the lower electrode comprises at least one layer of a metal material selected from the group consisting of titanium nitride (TiN), titanium aluminum nitride (TiAlN), tantalum nitride (TaN), tungsten nitride (WN), ruthenium (Ru), ruthenium oxide (RuO 2 ), iridium (Ir), iridium oxide (IrO 2 ), and niobium nitride (NbN).

15. The capacitor of claim 14 , wherein the layer of dielectric material is a layer of material selected from the group consisting of zirconium oxide (ZrO 2 ), hafnium oxide (HfO 2 ), tantalum oxide (Ta 2 O 3 ), aluminum oxide (Al 2 O 3 ), aluminum nitride (AlN), boron nitride (BN), zirconium nitride (Zr 3 N 4 ), hafnium nitride (Hf 3 N 4 ), and a lanthanide.

16. A capacitor having a lower electrode comprising a layer of a metal material; a dielectric on the lower electrode and comprising a layer of dielectric material having a crystal size larger than a crystal size of the metal material of the lower electrode; and an upper electrode disposed on the dielectric and comprising a layer of metal material having a crystal size smaller than the crystal size of the layer of dielectric material, and made by a process including steps of:
forming the lower electrode,
depositing dielectric material directly on the layer of metal material of the lower electrode and epitaxially growing the dielectric material to form a preliminary layer of dielectric material having a crystal size substantially the same as that of the metal material of the lower electrode, and
subsequently subjecting the preliminary layer of dielectric material to a heat treatment that causes crystals of the preliminary layer of dielectric material to merge together in respective groups thereof and thereby form the layer of dielectric material having the crystal size that is a multiple of the crystal size that of the metal material of the lower electrode.

17. The capacitor as formed by the process of claim 16 , wherein the crystal size of the layer of metal material of the lower electrode is in a range of 3-10 nanometers.

18. The capacitor as formed by the process of claim 16 , wherein the crystal size of the layer of dielectric material is 5-20 times the crystal size of the metal material of the lower electrode.

19. The capacitor as formed by the process of claim 16 , wherein the layer of metal material, upon which the dielectric material is directly deposited and grown into the preliminary layer of the dielectric material, is a layer of titanium nitride (TiN) or niobium nitride (NbN).

20. The capacitor as formed by the process of claim 16 , wherein the layer of metal material, upon which the dielectric material is directly deposited and grown into the preliminary layer of the dielectric material, has a <111> crystallographic direction.

Assignees

• Samsung Electronics Co Ltd

Inventors

• Kim Eun-Sun
• Kang Sang-Yeol
• Jung Kyoo-Ho
• Cho Kyu-Ho
• Mun Hyo-Sik

Classifications

• H10D64/035

  comprising conductor-insulator-conductor-insulator-semiconductor structures · CPC title

• H10D1/042

  using deposition processes to form electrode extensions · CPC title

• H10D1/696 Primary

  comprising multiple layers, e.g. comprising a barrier layer and a metal layer (barrier layers to prevent diffusion of hydrogen or oxygen in perovskite based capacitors H10D1/688) · CPC title

• H10D1/692 Primary

  Electrodes · CPC title

• H01G4/10

  Metal-oxide dielectrics {(H01G4/085 takes precedence)} · CPC title