METHODS OF DEPOSITING A RUTHENIUM FILM

• US 20080171436A1
• Filed: 01/10/2008
• Published: 07/17/2008
• Est. Priority Date: 01/11/2007
• Status: Abandoned Application

• Current Assignee: Asm Genitech Korea Ltd. (ASM International NV)
• Original Assignee: Asm Genitech Korea Ltd. (ASM International NV)
• Inventors: Lee, Chun Soo, Koh, Wonyong
• Application Number:
  US11/972,081
• Publication Number:
  US 20080171436A1
• Time in Patent Office: Days
• US Class Current: 438/681
• CPC Class Codes: C23C 16/18 from metallo-organic compounds
• CPC Class Codes: C23C 16/45525 Atomic layer deposition [ALD]
• CPC Class Codes: H01L 21/28562 Selective deposition

Abstract

Cyclical methods of depositing a ruthenium film on a substrate are provided. In one process, each cycle includes supplying a ruthenium organometallic compound gas to the reactor; purging the reactor; supplying a ruthenium tetroxide (RuO₄) gas to the reactor; and purging the reactor. In another process, each cycle includes simultaneously supplying RuO₄ and a reducing agent gas; purging; and supplying a reducing agent gas. The methods provide a high deposition rate while providing good step coverage over structures having a high aspect ratio.

Claims

1. A method of depositing a ruthenium film on a substrate, the method comprising:

loading a substrate into a reactor; and

conducting a plurality of deposition cycles, each cycle comprising steps of;

supplying a ruthenium organometallic compound gas to the reactor;

supplying an inert purge gas to the reactor;

supplying a ruthenium tetroxide (RuO₄) gas to the reactor; and

supplying an inert purge gas to the reactor.

2. The method of claim 1, wherein supplying the ruthenium tetroxide (RuO₄) gas to the reactor comprises supplying the ruthenium tetroxide (RuO₄) gas simultaneously with an oxidizing gas selected from the group of oxygen (O₂) gas and nitrous oxide (N₂O) gas.

3. The method of claim 2, wherein each cycle further comprises supplying oxygen (O₂) gas to the reactor before and/or after supplying the ruthenium tetroxide (RuO₄) gas to the reactor.

4. The method of claim 1, wherein supplying the ruthenium organometallic compound comprises supplying the ruthenium organometallic compound simultaneously with a reducing agent gas.

5. The method of claim 4, wherein each cycle further comprises supplying a reducing agent gas to the reactor before and/or after supplying the ruthenium organometallic compound gas.

6. The method of claim 4, wherein supplying the ruthenium tetroxide (RuO₄) gas to the reactor comprises supplying the ruthenium tetroxide (RuO₄) gas simultaneously with an oxidizing gas selected from the group of oxygen (O₂) gas and nitrous oxide (N₂O) gas.

7. The method of claim 6, wherein each cycle further comprises supplying a reducing agent gas to the reactor before and/or after supplying the ruthenium organometallic compound gas.

8. The method of claim 1, wherein the duration of each of the steps is between about 0.2 seconds and about 10 seconds.

9. The method of claim 1, wherein the cycles are conducted at a substrate temperature between about 140°

C. and about 500°

C.

10. The method of claim 1, wherein the ruthenium organometallic compound comprises a cyclopentadienyl compound of ruthenium.

11. The method of claim 1, wherein the reactor comprises a chemical vapor deposition reactor.

12. The method of claim 1, wherein the substrate comprises a feature having an aspect ratio of about 2:

1 or greater.

13. The method of claim 12, wherein the substrate comprises a feature having an aspect ratio of about 20:

1 or greater.

14. The method of claim 13, wherein the substrate comprises a plurality of features with aspect ratios greater than about 20:

1 in a partially fabricated memory array.

15. A method of making an electronic device, the method comprising:

providing a substrate into a reaction space; and

conducting a cyclical deposition on the substrate in the reaction space, each cycle comprising;

providing a ruthenium organometallic compound to the substrate;

removing any excess of the ruthenium organometallic compound from the reaction space;

providing ruthenium tetroxide (RuO₄) to the substrate; and

removing any excess of the ruthenium tetroxide from the reaction space.

16. The method of claim 15, wherein providing the ruthenium tetroxide (RuO₄) comprises supplying the ruthenium tetroxide (RuO₄) and an oxidizing gas selected from the group of oxygen (O₂) gas and nitrous oxide (N₂O) gas to the reaction space.

17. The method of claim 15, wherein providing the ruthenium organometallic compound comprises supplying the ruthenium organometallic compound and a reducing gas selected from the group consisting of a reducing agent gas to the reaction space.

18. The method of claim 17, wherein providing the ruthenium tetroxide comprises supplying the ruthenium tetroxide and an oxidizing gas selected from the group of oxygen (O₂) gas and nitrous oxide (N₂O) gas to the reaction space.

19. The method of claim 15, wherein each of removing any excess of the ruthenium organometallic compound and removing any excess of the ruthenium tetroxide comprises supplying purge gas.

20. A method of depositing a ruthenium film on a substrate, the method comprising:

loading a substrate in a reactor; and

conducting a plurality of deposition cycles, each cycle comprising in sequence;

supplying ruthenium tetroxide (RuO₄) gas and a reducing agent gas simultaneously to the reactor;

first supplying an inert purge gas to the reactor; and

supplying a reducing agent gas to the reactor.

21. The method of claim 20, wherein the reducing agent comprises at least one selected from the group consisting of H₂, SiH₄, Si₂H₈, BH₃, and B₂H₆.

22. The method of claim 20, wherein a duration of supplying the ruthenium tetroxide and the reducing agent is between about 1 second and about 10 seconds in each cycle.

23. The method of claim 20, wherein each cycle further comprises second supplying an inert purge gas to the reactor after supplying the reducing agent gas to the reactor.

24. The method of claim 23, wherein second supplying is conducted for less than about 10 seconds in each cycle.

25. The method of claim 20, wherein the cycles are conducted at a substrate temperature of about 140°

C. to about 500°

C.