Method of forming semiconductor device

• US 9,306,024 B2
• Filed: 01/29/2014
• Issued: 04/05/2016
• 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, Wang, Chin-Kun, Huang, Jhih-Jie, Chen, Miin-Jang
• Primary Examiner(s): DANG, PHUC T
• Application Number:
  US14/166,996
• Publication Number:
  US 20150214321A1
• Time in Patent Office: 797 Days
• Field of Search: 438/758
• 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 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 a 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.

2. The method of claim 1, 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.

3. The method of claim 2, 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.

4. The method of claim 1, 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.

5. The method of claim 1, at least one of:

repeating the first cycle;

or

repeating the second cycle.

6. The method of claim 1, 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.

7. The method of claim 1, 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.

8. A method of forming a semiconductor device 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;

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

annealing the first nitrogen doped zirconium oxide layer to form a dielectric film comprising a crystalline structure.

9. The method of claim 8, the forming a first zirconium layer comprising:

growing the zirconium layer over the dielectric layer.

10. The method of claim 8, the forming a first zirconium layer comprising:

depositing a zirconium precursor over the dielectric layer.

11. The method of claim 10, the zirconium precursor comprising Tetrakis-(ethylmethylamino) zirconium.

12. The method of claim 10, comprising:

delivering the zirconium precursor into a chamber comprising the dielectric layer by an inert carrier gas.

13. The method of claim 10, the depositing a zirconium precursor comprising depositing the zirconium precursor for a first duration of time and the doping the first zirconium layer comprising doping the first zirconium layer for a second duration of time.

14. The method of claim 13, the first duration of time equal to the second duration of time.

15. The method of claim 14, the applying remote oxygen plasma comprising applying the remote oxygen plasma for a third duration of time different than the first duration of time.

16. The method of claim 15, the third duration of time greater than the first duration of time.

17. The method of claim 13, the applying remote oxygen plasma comprising applying the remote oxygen plasma for a third duration of time greater than the first duration of time and greater than the second duration of time.

18. The method of claim 8, comprising:

forming a second zirconium layer over the first nitrogen doped zirconium oxide layer;

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

applying remote oxygen plasma to the second nitrogen doped zirconium layer to generate a second nitrogen doped zirconium oxide layer.

19. The method of claim 18, the annealing comprising:

concurrently annealing the first nitrogen doped zirconium oxide layer and the second nitrogen doped zirconium oxide layer.

20. A method of forming a semiconductor device comprising:

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

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

applying zirconium to the first nitrogen doped oxide layer to generate a 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 substantially uniform composition of zirconium, nitrogen and oxygen.