SEMICONDUCTOR DEVICE AND METHOD OF FABRICATING THE SAME

• US 20130126815A1
• Filed: 08/30/2012
• Published: 05/23/2013
• Est. Priority Date: 11/22/2011
• Status: Active Grant

• Current Assignee: SK Hynix Inc.
• Original Assignee: SK Hynix Inc.
• Inventors: KIM, Jin Hyock, Lee, Keun, Kwon, Young Seok
• Granted Patent: US 9,112,137 B2
• Time in Patent Office: Days
• US Class Current: 257/2
• CPC Class Codes: H01L 29/47 Schottky barrier electrodes H01L29/435 takes precedence
• CPC Class Codes: H01L 29/872 Schottky diodes
• CPC Class Codes: H10B 63/20 comprising selection components having two electrodes, e.g. diodes
• CPC Class Codes: H10N 70/028 by conversion of electrode material, e.g. oxidation
• 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 70/883 Oxides or nitrides

Abstract

A semiconductor device and a method of fabricating the same are provided. The semiconductor device includes a semiconductor substrate in which a word line region is formed, and a barrier metal layer arranged on the word line region and causing a Schottky junction. The barrier metal layer includes a first nitride material, in which a first material is nitrified, and a second nitride material, in which a second material is nitrified. The barrier metal layer is formed of a mixture of the first nitride material and the second nitride material. At least one of the first material or the second material is rich in a metal used to form the first nitride material or the second nitride material.

Claims

1. A semiconductor device, comprising:

a semiconductor substrate in which a word line region is formed; and

a barrier metal layer, formed of a metal nitride, arranged on the word line region and causing a Schottky junction, the barrier metal layer including;

a first nitride material formed of a nitrified first material; and

a second nitride material formed of a nitrified second material,

wherein the barrier metal layer is formed of a mixture of the first nitride material and the second nitride material, and

where any one of the first material or the second material is rich in a metal used to form the metal nitride.

2. The semiconductor device of claim 1, wherein the first material is titanium (Ti) and the second material is aluminum (Al).

3. The semiconductor device of claim 2, wherein the first nitride material and the second nitride material include nitride materials deposited by atomic layer deposition (ALD).

4. A semiconductor device, comprising:

a semiconductor substrate in which a word line region is formed; and

a barrier metal layer, formed of a metal nitride, arranged on the word line region and causing a Schottky junction,

the word line region including;

a first nitride material formed of a nitrified first material; and

a second nitride material formed of a nitrified second material,

wherein the word line region is formed of a mixture of the first nitride material and the second nitride material, and

wherein at least one of the first material or the second material is rich in a metal used to form the metal nitride.

5. The semiconductor device of claim 4, wherein the first material is titanium (Ti) and the second material is aluminum (Al).

6. The semiconductor device of claim 5, wherein the first nitride material and the second nitride material include nitride materials deposited by atomic layer deposition (ALD).

7. A method of fabricating a semiconductor device, the method comprising:

providing a semiconductor substrate in which a word line region is formed;

depositing a first material on the word line region;

forming a first nitride material by nitrifying the first material;

determining whether the first nitride material has a desired thickness, where if the first nitride material has the desired thickness, then;

depositing a second material on the first nitride material, forming a second nitride material by nitrifying the second material, and

determining whether the second nitride material is deposited to a desired thickness, where if the second nitride material has the desired thickness, then;

depositing a P+ polysilicon layer on the second nitride material, and

where the first material or the second material is rich in a material used to form the first nitride material or the second nitride material.

8. The method of claim 7, further comprising:

repeating the depositing of the first material and the forming of the first nitride material, if it is determined that the first nitride material does not have the desired thicknesses;

or

repeating the depositing of the second material and the forming of the second first nitride material, if it is determined that the first nitride material does not have the desired thicknesses.

9. The method of claim 8, wherein the first material is titanium (Ti) and the second material is aluminum (Al).

10. The method of claim 9, wherein depositing the first material and depositing the second material includes depositing the first material and the second material using atomic layer deposition (ALD).

11. The method of claim 7, wherein forming the first nitride material further comprises:

providing a first material precursor on the word line region of the semiconductor substrate;

performing a purge to remove impurities;

performing a hydrogen (H₂) process to remove ligands from the first material precursor;

performing a second purge to remove impurities; and

forming the first nitride material by nitrifying the first material using an ammonia (NH₃) gas or a NH₃ plasma process.

12. The method of claim 7, wherein forming the first nitride material further comprises:

providing a first material precursor on the word line region of the semiconductor substrate;

performing a purge to remove impurities;

forming the first nitride material by nitrifying the first material using an ammonia (NH₃) gas or a NH₃ plasma process; and

performing a second purge to remove impurities.

13. The method of claim 12, wherein the first material precursor includes any one selected from the group consisting of:

Ti(NEtMe)4 (TEMATi), tetrakis(dimethylamino)titanium I (TDMATi), titanium chloride (TiCl₄), titanium iodide (TiI₄), or titanium fluoride (TiF₄).

14. The method of claim 7, wherein forming the second nitride material further comprises:

providing a second material precursor on the first nitride material formed on the word line region;

performing a purge to remove impurities;

performing a hydrogen (H₂) process to remove ligands from the second material precursor;

performing a second purge to remove impurities; and

forming the second nitride material by nitrifying the second material using an ammonia (NH₃) gas or a NH₃ plasma process.

15. The method of claim 7, wherein forming the second nitride material further comprises:

providing a second material precursor on the first nitride material formed on the word line region;

performing a purge to remove impurities;

forming the second nitride material by nitrifying the second material using an ammonia (NH₃) gas or a NH₃ plasma process; and

performing a second purge to remove impurities.

16. The method of claim 15, in the second material precursor includes any one selected from the group consisting of:

trimethylaluminum (TMA), tritertiarybutylaluminum (TBA), or aluminum chloride (AlCl₃).

17. A method of fabricating a semiconductor device, the method comprising:

providing a semiconductor substrate;

depositing a first material on the semiconductor substrate;

nitrifying the first material to form a first nitride material;

determining whether the first nitride material has a desired thickness, where if the first nitride material has the desired thickness, then;

depositing a second material on the first nitride material,

nitrifying the second material to form a second nitride material, and

determining whether the second nitride material is deposited to a desired thickness, where if the second nitride material has the desired thickness, then;

forming a barrier metal layer on the second nitride material; and

depositing a P+ polysilicon layer on the barrier metal layer,

where at least one of the first material and the second material is rich in a metal used to form the first nitride material or the second nitride material.

18. The method of claim 17, further comprising:

repeating the depositing of the first material and the forming of the first nitride material, if it is determined that the first nitride material does not have the desired thicknesses;

or

repeating the depositing of the second material and the forming of the second first nitride material, if it is determined that the first nitride material does not have the desired thicknesses.

19. The method of claim 18, wherein the first material is titanium (Ti) and the second material is aluminum (Al).

20. The method of claim 19, wherein depositing the first material and depositing the second material includes depositing the first nitride material and the second nitride material using an atomic layer deposition (ALD).

21. The method of claim 17, wherein forming first nitride material further comprises:

providing a first material precursor on the semiconductor substrate;

performing a purge to remove impurities;

performing a hydrogen (H₂) process to remove ligands from the first material precursor;

performing a second purge to remove impurities; and

forming the first nitride material by nitrifying the first material using an ammonia (NH₃) gas or a NH₃ plasma process.

22. The method of claim 17, wherein forming the first nitride material further comprises:

providing a first material precursor on the semiconductor substrate;

performing a purge to remove impurities;

forming the first nitride material by nitrifying the first material using an ammonia (NH₃) gas or a NH₃ plasma process; and

performing a second purge to remove impurities other than the first material.

23. The method of claim 22, wherein the first material precursor includes any one of:

Ti(NEtMe)4 (TEMATi), tetrakis(dimethylamino)titanium I (TDMATi), titanium chloride (TiCl₄), titanium iodide (TiI₄), or titanium fluoride (TiF₄).

24. The method of claim 17, wherein forming the second nitride material further comprises:

providing a second material precursor on the first nitride material;

performing a purge to remove impurities;

performing a hydrogen (H₂) process to remove ligands from the second material precursor;

performing a second purge to remove impurities; and

forming the second nitride material by nitrifying the second material using an ammonia (NH₃) gas or a NH₃ plasma process.

25. The method of claim 17, wherein forming the second nitride material further comprises:

providing a second material precursor on the first nitride material;

performing a purge to remove impurities;

forming the second nitride material by nitrifying the second material using an ammonia (NH₃) gas or a NH₃ plasma process; and

performing a second purge to remove impurities other than the second material.

26. The method of claim 25, wherein the second material precursor includes any one selected from the group consisting of:

trimethylaluminum (TMA), tritertiarybutylaluminum (TBA), or aluminum chloride (AlCl₃).