Selective deposition of noble metal thin films

• US 8,927,403 B2
• Filed: 07/21/2011
• Issued: 01/06/2015
• Est. Priority Date: 03/15/2005
• Status: Active Grant

• Current Assignee: ASM International NV
• Original Assignee: ASM International NV
• Inventors: Huotari, Hannu, Tuominen, Marko, Leinikka, Miika
• Primary Examiner(s): Kebede, Brook
• Application Number:
  US13/188,087
• Publication Number:
  US 20120009773A1
• Time in Patent Office: 1,265 Days
• Field of Search: 438/585, 438/589, 438/758, 438/785, 438/789, 438/790, 427/576
• US Class Current: 438/584
• CPC Class Codes: C23C 16/32 Carbides
• CPC Class Codes: C23C 16/34 Nitrides C23C16/303 takes precedence
• CPC Class Codes: C23C 16/38 Borides
• CPC Class Codes: C23C 16/40 Oxides
• CPC Class Codes: C23C 16/45525 Atomic layer deposition [ALD]
• CPC Class Codes: H01L 21/28079 the final conductor layer next to the insulator being a single metal, e.g. Ta, W, Mo, Al
• CPC Class Codes: H01L 29/517 the insulating material comprising a metallic compound, e.g. metal oxide, metal silicate H01L29/518 takes precedence
• CPC Class Codes: H01L 29/66583 with initial gate mask or masking layer complementary to the prospective gate location, e.g. with dummy source and drain contacts

Abstract

Processes are provided for selectively depositing thin films comprising one or more noble metals on a substrate by vapor deposition processes. In some embodiments, atomic layer deposition (ALD) processes are used to deposit a noble metal containing thin film on a high-k material, metal, metal nitride or other conductive metal compound while avoiding deposition on a lower k insulator such as silicon oxide. The ability to deposit on a first surface, such as a high-k material, while avoiding deposition on a second surface, such as a silicon oxide or silicon nitride surface, may be utilized, for example, in the formation of a gate electrode.

Claims

1. A method of selectively depositing a thin film on a first surface of a substrate in a reactor relative to a second surface, the method comprising conducting a plurality of deposition cycles comprising:

supplying a noble metal precursor to the reactor;

supplying a purge gas to the reactor after supplying the noble metal precursor; and

supplying ammonia gas to the reactor after supplying the purge gas;

wherein the ammonia gas does not comprise ammonia plasma;

and wherein the first surface comprises a high-k material, a metal, a metal nitride, a metal oxide, a metal carbide, a metal boride, another conductive metal compound or mixtures thereof;

the second surface comprises a material selected from the group consisting of silicon oxides, silicon nitrides, silicon oxynitrides, fluorinated silica glass (FSG), carbon doped silicon oxide (SiOC) and materials containing more than about 50% silicon oxide;

and the thin film is selectively deposited on the first surface relative to the second surface.

2. The method of claim 1, wherein the temperature of the reactor is maintained at less than about 350°

C. during the at least one of the cycles.

3. The method of claim 1, wherein the temperature of the reactor is maintained at about 200°

C. to about 400°

C. during the at least one of the cycles.

4. The method of claim 1, wherein supplying the ammonia gas comprises supplying the ammonia gas for a duration of about 1 second to about 5 seconds.

5. The method of claim 1, wherein the noble metal precursor comprises ruthenium.

6. The method of claim 5, wherein the ruthenium precursor is selected from the group consisting of:

bis(cyclopentadienyl)ruthenium, tris(2,2,6,6 - tetramethl-3,5-)ruthenium, tris(N,N′

-diisopropylacetamidinato)ruthenium(III), bis(N,N′

-diisopropylacetamidinato)ruthenium(II) dicarbonyl, bis(ethylcyclopentadienyl)ruthenium, bis(pentamethylcyclopentadienyl)ruthenium and bis(2,2,6,6-tetramethyl-3,5-heptanedionato)(1,5-cyclooctadiene)ruthenium(II).

7. The method of claim 2, wherein the at least one of the cycles further comprises supplying a purge gas after supplying the ammonia gas.

8. The method of claim 1, wherein the first surface is selected from the group consisting of:

Ta, TaN, TaC_x, TaB_x, Ti,TiN, TiC_x, TiB_x, Nb, NbN, NbC_x, NbB_x Mo, MoN, MoC_x, MoB_x, W, WN, WC_x, WB_x,V, Cr, Fe, Cu, Co, Ni, Cd, Zn, Al Ag, Au, Ru, RuO_x, Rh, Pt, Pd, Ir, IrO_x and Os.

9. The method of claim 1, wherein conducting the plurality of deposition cycles comprises depositing a ruthenium layer directly on the first surface.

10. The method of claim 9, further comprising depositing a conductive material directly on the ruthenium layer.

11. The method of claim 1, wherein conducting the plurality of deposition cycles comprises depositing a ruthenium layer selectively on the first surface of the substrate relative to the second surface.

12. The method of claim 1, wherein the substrate includes a surface that includes a structure selected from a via or trench, and wherein a layer deposited by conducting a plurality of deposition cycles conforms to the structure.

13. A method for depositing a noble metal thin film on a substrate in a reaction chamber, the method comprising multiple pulsing cycles, each cycle comprising:

pulsing a vaporized noble metal precursor into the reaction chamber to form a molecular layer of the noble metal precursor on a first surface of the substrate,

purging the reaction chamber to remove excess noble metal precursor and reaction by-products, if any,

providing a pulse of a second reactant comprising ammonia plasma to the substrate,

purging the reaction chamber to remove excess second reactant and any gaseous by-products formed in the reaction, and

repeating the pulsing and purging steps until a thin film of a desired thickness has been formed,

wherein the first surface of the substrate comprises a high-k material, a metal, or a conductive metal compound.

14. The method of claim 13, wherein the substrate has a temperature of less than about 400°

C. during the pulsing cycles.

15. The method of claim 13, wherein the first surface comprises a metal nitride.

16. The method of claim 13, wherein the substrate comprises a second surface comprising a material selected from the group consisting of silicon oxides, silicon nitrides, silicon oxynitrides, fluorinated silica glass (FSG), carbon doped silicon oxide (SiOC) and materials containing more than about 50% silicon oxide

17. The method of claim 16, wherein conducting the multiple pulsing cycles comprises depositing the noble metal thin film selectively on the first surface of the substrate relative to the second surface.

18. The method of claim 13, further comprising depositing a conductive material directly on the noble metal thin film.

19. The method of claim 13, wherein the noble metal comprises ruthenium.

20. The method of claim 19, wherein the ruthenium precursor is selected from the group consisting of:

bis(cyclopentadienyl)ruthenium, tris(2,2,6,6-tetramethyl-3,5-heptanedionato)ruthenium, tris(N,N′

-diisopropylacetamidinato)ruthenium(III), bis(N,N-diisopropylacetamidinato)ruthenium(II) dicarbonyl, bis(ethylcyclopentadienyl)ruthenium, bis(pentamethylcyclopentadienyl)ruthenium and bis(2,2,6,6-tetramethyl-3,5-heptanedionato)(1,5-cyclooctadiene)ruthenium(II).

21. A method for depositing a noble metal thin film on a substrate in a reaction chamber, the method comprising a plurality of pulsing cycles, each cycle comprising:

pulsing a vaporized noble metal precursor into the reaction chamber to form a molecular layer of the noble metal precursor on a first surface of the substrate comprising a high-k material, a metal, or a conductive metal compound,

purging the reaction chamber to remove excess noble metal precursor and reaction by-products, if any,

providing a pulse of a second reactant comprising ammonia plasma to the substrate,

purging the reaction chamber to remove excess second reactant and any gaseous by-products formed in the reaction, and

repeating the pulsing and purging steps until a thin film of a desired thickness has been formed on the first surface of the substrate.

22. The method of claim 21, wherein the substrate further comprises a second surface comprising a material selected from the group consisting of silicon oxides, silicon nitrides, silicon oxynitrides, fluorinated silica glass (FSG), carbon doped silicon oxide (SiOC) and materials containing more than about 50% silicon oxide.

23. The method of claim 21, wherein repeating the plurality of pulsing cycles comprises depositing the noble metal thin film selectively on the first surface of the substrate relative to the second surface.