Deposition of metal borides

• US 10,087,522 B2
• Filed: 04/21/2016
• Issued: 10/02/2018
• Est. Priority Date: 04/21/2016
• Status: Active Grant

• Current Assignee: ASM IP Holding B.V. (ASM International NV)
• Original Assignee: ASM IP Holding B.V. (ASM International NV)
• Inventors: Raisanen, Petri, Shero, Eric, Haukka, Suvi, Milligan, Robert Brennan, Givens, Michael Eugene
• Primary Examiner(s): Chen, Bret P
• Application Number:
  US15/135,224
• Publication Number:
  US 20170306478A1
• Time in Patent Office: 894 Days
• CPC Class Codes: C23C 16/38 Borides
• CPC Class Codes: C23C 16/45523 Pulsed gas flow or change of composition over time
• CPC Class Codes: C23C 16/45525 Atomic layer deposition [ALD]

Abstract

A method for depositing a metal boride film onto a substrate is disclosed. In particular, the method comprises pulsing a metal halide precursor onto the substrate and pulsing a boron compound precursor onto the substrate. A reaction between the metal halide precursor and the boron compound precursor forms a metal boride film. Specifically, the method discloses forming a tantalum boride (TaB₂) or a niobium boride (NbB₂) film.

Claims

1. A method of forming a metal boride comprising:

providing a substrate for processing in a reaction chamber;

performing a metal halide precursor deposition onto the substrate, the performing the metal halide precursor deposition step comprises;

pulsing a metal halide precursor comprising at least one of niobium tetrafluoride (NbF₄) and niobium pentafluoride (NbF₅) onto the substrate; and

purging an excess of the metal halide precursor from the reaction chamber; and

performing a borane compound precursor deposition onto the substrate, the performing the borane compound precursor deposition step comprises;

pulsing a borane compound precursor onto the substrate; and

purging an excess of the borane compound precursor from the reaction chamber;

wherein the metal halide precursor comprises a niobium halide;

wherein a reaction between the metal halide precursor and the borane compound precursor forms a niobium boride film;

wherein the metal halide precursor deposition step is repeated a predetermined number of times; and

wherein the borane compound precursor deposition step is repeated a predetermined number of times.

2. The method of claim 1, wherein the borane compound precursor comprises at least one of:

borane (BH₃), diborane (B₂H₆), triborane (B₃H₈), tetraborane (B₄H₁₀), pentaborane, hexaborane, heptaborane, octaborane, nonaborane, decaborane, borane compounds that consist of only boron and hydrogen, amine boranes, cyclic borides, borazines, and borane compounds that do not include carbon, and other boron-containing precursors.

3. The method of claim 1, wherein a temperature of the reaction chamber ranges between 200 and 400°

C.

4. The method of claim 1, wherein a pressure of the reaction chamber ranges between 0.5 and 8 Torr.

5. The method of claim 1, wherein the pulsing the metal halide precursor has a duration between 0.1 and 10 seconds.

6. The method of claim 1, wherein the pulsing the borane compound precursor has a duration between 0.1 and 10 seconds.

7. The method of claim 1, wherein pulsing a borane compound precursor onto the substrate comprises adsorbing more than one monolayer of the borane compound onto the substrate.

8. The method of claim 1, wherein one or more of purging the excess of the borane compound precursor and purging an excess of the metal halide precursor comprises flowing the borane compound precursor onto the substrate.

9. A method of forming a metal boride work function layer comprising:

providing a substrate for processing in a reaction chamber;

performing a metal halide precursor deposition onto the substrate, the performing the metal halide precursor deposition step comprises;

pulsing a metal halide precursor onto the substrate; and

purging an excess of the metal halide precursor from the reaction chamber; and

performing a borane compound precursor deposition onto the substrate, the performing the borane compound precursor deposition step comprises;

pulsing a borane compound precursor onto the substrate; and

purging an excess of the borane compound precursor from the reaction chamber;

wherein the metal halide precursor comprises one of;

tantalum pentafluoride (TaF₅), niobium tetrafluoride (NbF₄), or niobium pentafluoride (NbF₅); and

wherein a reaction between the metal halide precursor and the borane compound precursor forms a metal boride comprising at least one of;

tantalum boride (TaB₂) or niobium boride (NbB₂).

10. The method of claim 9, wherein the borane compound precursor comprises at least one of:

borane (BH₃), diborane (B₂H₆), triborane (B₃H₈), tetraborane (B₄H₁₀), pentaborane, hexaborane, heptaborane, octaborane, nonaborane, decaborane, borane compounds that consist of only boron and hydrogen, amine boranes, cyclic borides, borazines, and borane compounds that do not include carbon, and other boron-containing precursors.

11. The method of claim 9, wherein a temperature of the reaction chamber ranges between 200 and 400°

C.

12. The method of claim 9, wherein a pressure of the reaction chamber ranges between 0.5 and 8 Torr.

13. The method of claim 9, wherein the pulsing the metal halide precursor has a duration ranging between 0.1 and 10 seconds.

14. The method of claim 9, wherein the pulsing the borane compound precursor has a duration ranging between 0.1 and 10 seconds.

15. The method of claim 9, wherein pulsing a borane compound precursor onto the substrate comprises adsorbing more than one monolayer of the borane compound onto the substrate.

16. The method of claim 9, wherein one or more of purging the excess of the boron compound precursor and purging an excess of the metal halide precursor comprises flowing the borane compound precursor onto the substrate.

17. The method of claim 9, wherein the metal boride has a concentration of Boron from about 30 to about 80 at. %.

18. The method of claim 9, wherein the metal boride has a concentration of niobium or tantalum from about 20 to about 70 at. %.

19. The method of claim 9, wherein the metal boride has a concentration of Oxygen of less than 5 at. %.

20. The method of claim 9, wherein the metal boride has a concentration of Hydrogen of less than 5 at. %.

21. The method of claim 9, wherein the metal boride has a concentration of Fluorine of less than 5 at. %.