Methods of forming a ferroelectric memory cell

Patent metadata

Field	Value
Publication number	US-9231206-B2
Application number	US-201314026883-A
Country	US
Kind code	B2
Filing date	Sep 13, 2013
Priority date	Sep 13, 2013
Publication date	Jan 5, 2016
Grant date	Jan 5, 2016

Abstract

A method of forming a ferroelectric memory cell. The method comprises forming an electrode material exhibiting a desired dominant crystallographic orientation. A hafnium-based material is formed over the electrode material and the hafnium-based material is crystallized to induce formation of a ferroelectric material having a desired crystallographic orientation. Additional methods are also described, as are semiconductor device structures including the ferroelectric material.

First claim

What is claimed is:

1. A method of forming a ferroelectric memory cell, comprising:
forming an electrode material comprising titanium nitride by atomic layer deposition;
forming a hafnium-based material over the electrode material; and
crystallizing the hafnium-based material to induce formation of a ferroelectric material having a desired crystallographic orientation.

2. The method of claim 1 , wherein forming an electrode material comprising titanium nitride by atomic layer deposition comprises forming crystalline titanium nitride.

3. The method of claim 1 , wherein forming an electrode material comprising titanium nitride by atomic layer deposition comprises forming titanium nitride in a dominant (111) crystallographic orientation.

4. The method of claim 3 , wherein forming titanium nitride in a dominant (111) crystallographic orientation comprises forming the titanium nitride in the dominant (111) crystallographic orientation using an organometallic precursor.

5. The method of claim 3 , wherein forming titanium nitride in a dominant (111) crystallographic orientation comprises forming the titanium nitride in the dominant (111) crystallographic orientation using titanium tetrachloride and ammonia.

6. The method of claim 3 , wherein crystallizing the hafnium-based material comprises forming orthorhombic hafnium silicate over the titanium nitride in the dominant (111) crystallographic orientation.

7. The method of claim 3 , wherein crystallizing the hafnium-based material comprises forming hafnium silicate in a dominant (200) crystallographic orientation over the titanium nitride in the dominant (111) crystallographic orientation.

8. The method of claim 3 , wherein forming hafnium silicate over the titanium nitride in the dominant (111) crystallographic orientation comprises forming hafnium silicate in a dominant (200) crystallographic orientation over the titanium nitride in the dominant (111) crystallographic orientation.

9. The method of claim 1 , wherein forming a hafnium-based material over the electrode material comprises forming an amorphous hafnium-based material over the electrode material.

10. The method of claim 1 , wherein forming a hafnium-based material over the electrode material comprises forming hafnium silicate, hafnium aluminate, hafnium zirconate, strontium-doped hafnium oxide, magnesium-doped hafnium oxide, gadolinium-doped hafnium oxide, yttrium-doped hafnium oxide, or combinations thereof over the electrode material.

11. The method of claim 1 , wherein crystallizing the hafnium-based material comprises annealing the hafnium-based material.

12. A method of forming a ferroelectric memory cell, comprising:
forming an electrode material comprising titanium nitride in a dominant (111) crystallographic orientation;
forming an amorphous hafnium silicate material over the electrode material;
forming another electrode material over the amorphous hafnium silicate material; and
crystallizing the amorphous hafnium silicate material to induce formation of a dominant (200) crystallographic orientation of the hafnium silicate.

13. The method of claim 12 , wherein forming an electrode material comprising titanium nitride in a dominant (111) crystallographic orientation comprises forming the titanium nitride by an atomic layer deposition process.

14. The method of claim 12 , wherein crystallizing the amorphous hafnium silicate material to induce formation of a dominant (200) crystallographic orientation of the hafnium silicate comprises exposing the amorphous hafnium silicate material to a temperature greater than about 800° C.

15. The method of claim 12 , wherein forming another electrode material over the amorphous hafnium silicate material comprises forming titanium nitride over the amorphous hafnium silicate material.

16. A method of forming a ferroelectric memory cell, comprising:
forming a titanium nitride material comprising

forming the titanium nitride in a dominant (111) crystallographic orientation by atomic layer deposition;
forming an amorphous hafnium-based material over the titanium nitride material; and
crystallizing the amorphous hafnium-based material to induce formation of a dominant crystallographic orientation.

17. The method of claim 16 , wherein forming an amorphous hafnium-based material over the titanium nitride material comprises forming hafnium silicate, hafnium aluminate, hafnium zirconate, strontium-doped hafnium oxide, magnesium-doped hafnium oxide, gadolinium-doped hafnium oxide, yttrium-doped hafnium oxide, or combinations thereof over the titanium nitride material.

18. The method of claim 16 , wherein forming an amorphous hafnium-based material over the titanium nitride material comprises forming hafnium silicate comprising from about 4.4 mol % to about 5.6 mol % silicon over the titanium nitride material.

19. The method of claim 16 , wherein crystallizing the amorphous hafnium-based material to induce formation of a dominant crystallographic orientation comprises forming hafnium silicate comprising a dominant (200) crystallographic orientation.

20. The method of claim 16 , wherein forming a titanium nitride material comprising a dominant (111) crystallographic orientation comprises forming a greater amount of the titanium nitride material in the (111) crystallographic orientation than in another crystallographic orientation.

Assignees

• Micron Technology Inc

Inventors

• Tao Qian
• Rocklein Matthew N
• Cook Beth R
• Ramaswamy D V Nirmal

Classifications

• H10D1/692 Primary

  Electrodes · CPC title

• H01L45/1608 Primary

  Electricity · mapped topic

• H01L45/04

  Electricity · mapped topic

• H01L28/60

  Electricity · mapped topic

• H01L45/1641

  Electricity · mapped topic