METHOD FOR FORMING RUTHENIUM COMPLEX FILM USING Beta-DIKETONE-COORDINATED RUTHENIUM PRECURSOR

• US 20090087339A1
• Filed: 09/03/2008
• Published: 04/02/2009
• Est. Priority Date: 09/28/2007
• Status: Abandoned Application

• Current Assignee: ASM Japan K.K. (ASM International NV)
• Original Assignee: ASM Japan K.K. (ASM International NV)
• Inventors: Shinriki, Hiroshi
• Application Number:
  US12/203,405
• Publication Number:
  US 20090087339A1
• Time in Patent Office: Days
• US Class Current: 420/462
• CPC Class Codes: C23C 16/18 from metallo-organic compounds
• CPC Class Codes: C23C 16/45542 Plasma being used non-continuously during the ALD reactions
• CPC Class Codes: H01L 21/28562 Selective deposition
• CPC Class Codes: H01L 21/76843 formed in openings in a dielectric
• CPC Class Codes: H01L 21/76846 Layer combinations
• CPC Class Codes: H01L 21/76873 for electroplating

Abstract

A method for depositing a thin ruthenium (Ru) film on a substrate in a reaction chamber, comprising: step (i) of supplying at least one type of gas of a ruthenium precursor being a β-diketone-coordinated ruthenium complex and causing the gas to be adsorbed to the substrate in the reaction chamber; step (ii) of supplying a reducing gas into the reaction chamber and exciting the reducing gas, or supplying an excited reducing gas into the reaction chamber, in order to activate the ruthenium precursor adsorbed to the substrate; and step (iii) of repeating steps (i) and (ii) to form a thin ruthenium film on the substrate.

Claims

1. A method for depositing a thin ruthenium (Ru) film on a substrate in a reaction chamber, comprising:

step (i) of supplying at least one type of gas of a ruthenium precursor being a β

-diketone-coordinated ruthenium complex and causing the gas to be adsorbed to the substrate in the reaction chamber;

step (ii) of supplying a reducing gas into the reaction chamber and exciting the reducing gas, or supplying an excited reducing gas into the reaction chamber, thereby activating the ruthenium precursor adsorbed to the substrate; and

step (iii) of repeating steps (i) and (ii) to form a thin ruthenium film on the substrate.

2. The method according to claim 1, wherein the ruthenium complex has a Ru(X)n structure (X is a β

-diketone ligand, while n is 2 or

     3).

3. The method according to claim 2, wherein the β

-diketone group expressed by Xa is a 2,4-pentenedione group where at least one of carbon 1 and carbon 5 is bonded to an alkyl group.

4. The method according to claim 2, wherein the β

-diketone group expressed by Xb is a 2,4-pentenedione group where at least one of carbon 1 and carbon 5 is bonded to an alkyl group.

5. The method according to claim 3, wherein the β

-diketone group expressed by Xa is an acetyl acetone group, dipivaloyl methane group, diisobutyryl methane group or isopivaloyl methane group.

6. The method according to claim 4, wherein the β

-diketone group expressed by Xb is an acetyl acetone group, dipivaloyl methane group, diisobutyryl methane group or isopivaloyl methane group.

7. The method according to claim 1, wherein the gas supplied in step (ii) is a reducing gas and this reducing gas is at least one of hydrogen, mixture gas of hydrogen and nitrogen, or gas constituted by hydrogen atoms.

8. The method according to claim 1, wherein the gas supplied in step (ii) is an excited reducing gas and this step includes a step to generate a reducing gas that has been excited by applying high-frequency power to the reducing gas upstream of the reaction chamber.

9. The method according to claim 1, further comprising a step of purging the ruthenium precursor from the reaction chamber after step (i) and a step of purging the excited reducing gas from the reaction chamber after step (ii).

10. The method according to claim 1, wherein steps (i) and (ii) are repeated until the thickness of the formed thin ruthenium film becomes 0.5 nm or more, but not exceeding 2.0 nm.

11. The method according to claim 1, wherein steps (i) and (ii) are repeated until the preferred crystalline orientation of the formed thin ruthenium film becomes Ru (002).

12. The method according to claim 1, wherein steps (i) and (ii) are repeated until the thickness of the formed thin ruthenium film becomes 0.5 nm or more, but not exceeding 2.0 nm and also until the preferred crystalline orientation of the ruthenium film becomes Ru (002).

13. The method according to any one of claim 1, further comprising a step of forming a metal film on the substrate before the start of steps (i) to (iii) for forming a thin ruthenium film.

14. The method according to claim 13, wherein the metal film is at least one type selected from the group consisting of WNxCy, WN, TaN, RuTaN, Ta, RuTa, TaNxCy, RuTaNxCy, TiN, RuTiN, Ti, and RuTi.

15. The method according to claim 1, further comprising after step (iii):

step (iv) of supplying gas of a ruthenium precursor into the reaction chamber and causing the gas to be adsorbed to the substrate;

step (v) of supplying into the reaction chamber an oxidizing gas or molecules constituted by oxygen atoms so as to activate the ruthenium precursor adsorbed to the substrate; and

step (vi) of repeating steps (iv) and (v) and thereby forming a thin ruthenium film or thin ruthenium oxide film on the thin ruthenium film formed in step (iii).

16. The method according to claim 1, further comprising a step of forming a copper film on the thin ruthenium film after step (iii).

17. The method according to claim 15, further comprising a step of forming a copper film on the thin ruthenium film or thin ruthenium oxide film formed in the step following step (iii).

18. The method according to claim 11, further comprising, after step (iii), a step of forming a copper film on the thin ruthenium film having (002)-preferred crystal orientation.

19. The method according to claim 12, further comprising, after step (iii), a step of forming a copper film on the thin ruthenium film having a thickness of 0.5 nm or more, but not exceeding 2.0 nm, and (002)-preferred crystalline orientation.

21. The method according to claim 2, wherein the Ru(X)n structure has a Xa-Ru-Xb or Xa-Ru-Xa structure where Xa and Xb represent different β

-diketone ligands.

20. A thin ruthenium film formation structure, comprising:

a substrate, and

a thin ruthenium film formed on the substrate by the atomic layer deposition method and having (002)-preferred crystalline orientation.