SEMICONDUCTOR DEVICE AND FORMATION THEREOF

• US 20150214321A1
• Filed: 01/29/2014
• Published: 07/30/2015
• Est. Priority Date: 01/29/2014
• Status: Active Grant

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Inventors: Chi, Liang-Chen, Tsai, Chia-Ming, Chen, Miin-Jang, Wang, Chin-Kun, Huang, Jhih-Jie
• Granted Patent: US 9,306,024 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01L 21/02189 the material containing zirconium, e.g. ZrO2
• CPC Class Codes: H01L 21/02274 in the presence of a plasma [PECVD]
• CPC Class Codes: H01L 21/0228 deposition by cyclic CVD, e.g. ALD, ALE, pulsed CVD
• CPC Class Codes: H01L 21/28229 by deposition of a layer, e.g. metal, metal compound or poysilicon, followed by transformation thereof into an insulating layer
• CPC Class Codes: H01L 29/513 the variation being perpendicular to the channel plane
• CPC Class Codes: H01L 29/518 the insulating material containing nitrogen, e.g. nitride, oxynitride, nitrogen-doped material

Abstract

A semiconductor device and methods of formation are provided. A semiconductor device includes a dielectric film over a dielectric layer. The dielectric film includes a crystalline structure having a substantially uniform composition of zirconium, nitrogen and oxygen. The dielectric film is formed through in situ nitrogen plasma doping of a zirconium layer. The dielectric film functions as a gate dielectric. The dielectric film has a high dielectric constant between about 28-29 and has a low leakage current density of about 4.79×10⁻⁵ A/cm². The substantially uniform distribution of nitrogen throughout the zirconium oxide of the dielectric film increases the k value of the dielectric film by between about 15% to about 17% as compared to a dielectric film that has a non-uniform distribution of nitrogen through a zirconium oxide layer.

Claims

1. A semiconductor device, comprising:

a dielectric layer comprising oxide; and

a dielectric film over the dielectric layer, the dielectric film comprising a crystalline structure comprising a substantially uniform composition of zirconium, nitrogen and oxygen.

2. The semiconductor device of claim 1, the dielectric layer having a dielectric layer thickness between about 5 Å

to about 15 Å

.

3. The semiconductor device of claim 1, the dielectric layer comprising silicon.

4. The semiconductor device of claim 1, comprising:

a gate electrode; and

a gate dielectric under the gate electrode, the gate dielectric comprising the dielectric layer and the dielectric film.

5. The semiconductor device of claim 1, the dielectric film comprising between about 20% to about 40% zirconium.

6. The semiconductor device of claim 1, the dielectric film comprising between about 25% to about 75% oxygen.

7. The semiconductor device of claim 1, the dielectric film comprising between about 5% to about 35% nitrogen.

8. The semiconductor device of claim 1, the dielectric film having a dielectric film thickness between about 25 Å

to about 75 Å

.

9. A method of forming a semiconductor device comprising at least one of:

a first cycle, the first cycle comprising;

forming a first zirconium layer over a dielectric layer of the semiconductor device;

doping the first zirconium layer using nitrogen plasma to generate a first nitrogen doped zirconium layer; and

applying remote oxygen plasma to the first nitrogen doped zirconium layer to generate a first nitrogen doped zirconium oxide layer;

or

a second cycle, the second cycle comprising;

applying remote oxygen plasma to the dielectric layer to form a first oxide layer over the dielectric layer;

doping the first oxide layer using the nitrogen plasma to generate a first nitrogen doped oxide layer; and

applying zirconium to the first nitrogen doped oxide layer to generate the first nitrogen doped zirconium oxide layer; and

annealing the semiconductor device to form a dielectric film from the first nitrogen doped zirconium oxide layer, the dielectric film comprising a crystalline structure, the crystalline structure comprising a substantially uniform composition of zirconium, nitrogen and oxygen.

10. The method of claim 9, at least one of:

the forming a first zirconium layer comprising performing a first atomic layer deposition (ALD) of a zirconium precursor, the zirconium precursor comprising Tetrakis-(ethylmethylamino) zirconium (TEMAZ, Zr[N(C₂H₅)CH₃]₄);

or

the applying zirconium comprising performing a second ALD of the zirconium precursor.

11. The method of claim 10, at least one of the first ALD or the second ALD performed at a first temperature between about 150°

C. to about 350 C.° and

at a first pressure between about 0.05 torr to about 0.5 torr.

12. The method of claim 9, at least one of:

the doping the first zirconium layer comprising in situ doping the first zirconium layer using at least one of N₂ plasma or NH₃ plasma;

or

the doping the first oxide layer comprising in situ doping the first oxide layer using at least one of N₂ plasma or NH₃ plasma.

13. The method of claim 9, at least one of:

repeating the first cycle;

or

repeating the second cycle.

14. The method of claim 9, the annealing comprising annealing at an annealing temperature between about 300°

C. to about 600 C.°

for an annealing duration between about 20 min to about 40 min, in the presence of an annealing gas, the annealing gas comprising at least one of argon, nitrogen, or hydrogen.

15. The method of claim 9, occurring within a chamber, the chamber purged using an inert gas between the forming a first zirconium layer and the doping the first zirconium layer, such that a zirconium precursor is removed from the chamber.

16. A semiconductor device, comprising:

a dielectric layer comprising oxide; and

a dielectric film over the dielectric layer, the dielectric film comprising a crystalline structure comprising a substantially uniform composition comprising between about 20% to about 40% zirconium, between about 25% to about 75% oxygen and between about 5% to about 35% nitrogen.

17. The semiconductor device of claim 16, comprising:

a gate electrode; and

a gate dielectric under the gate electrode, the gate dielectric comprising the dielectric layer and the dielectric film.

18. The semiconductor device of claim 16, the dielectric film having a dielectric film thickness between about 25 Å

to about 75 Å

.

19. The semiconductor device of claim 16, the dielectric layer having a dielectric layer thickness between about 5 Å

to about 15 Å

.

20. The semiconductor device of claim 16, the dielectric layer comprising silicon.