Hydrogenation and nitridization processes for reducing oxygen content in a film

• US 10,504,779 B2
• Filed: 01/28/2019
• Issued: 12/10/2019
• Est. Priority Date: 06/20/2016
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Swenberg, Johanes S., Liu, Wei, Graoui, Houda, Sharma, Shashank, Muthukrishnan, Shankar, George, Rene
• Primary Examiner(s): Lee, Kyoung
• Assistant Examiner(s): Sylvia, Christina A
• Application Number:
  US16/260,084
• Publication Number:
  US 20190157143A1
• Time in Patent Office: Days
• CPC Class Codes: H01L 21/28518 the conductive layers comprising silicides H01L21/28537 takes precedence
• CPC Class Codes: H01L 21/28556 by chemical means, e.g. CVD, LPCVD, PECVD, laser CVD H01L21/28518 - H01L21/28537 and H01L21/28568 take precedence
• CPC Class Codes: H01L 21/28568 the conductive layers comprising transition metals H01L21/28518 takes precedence
• CPC Class Codes: H01L 21/76843 formed in openings in a dielectric
• CPC Class Codes: H01L 21/7685 the layer covering a conductive structure H01L21/76849 takes precedence
• CPC Class Codes: H01L 21/76855 After-treatment introducing at least one additional element into the layer
• CPC Class Codes: H01L 21/76856 by treatment in plasmas or gaseous environments, e.g. nitriding a refractory metal liner
• CPC Class Codes: H01L 21/76862 Bombardment with particles, e.g. treatment in noble gas plasmas; UV irradiation
• CPC Class Codes: H01L 21/76889 by forming silicides of refractory metals

Abstract

Embodiments described herein generally relate to a sequential hydrogenation and nitridization process for reducing interfacial and bulk O atoms in a conductive structure in a semiconductor device. A hydrogenation and plasma nitridization process is performed on a metal nitride layer in a conductive structure prior to deposition of a second metal layer, thereby reducing interfacial oxygen atoms formed on a surface of the metal nitride and oxygen atoms present in the bulk metal layers of the conductive structure. As a result, adhesion of the second metal layer to the metal nitride layer is improved and the electrical resistance of the contact structure is reduced.

Claims

1. A method of forming a structure in a semiconductor device, comprising:

performing an oxygen-free plasma treatment process on a processing chamber component disposed within a processing chamber in which the processing chamber component is exposed to a non-oxidizing plasma comprising hydrogen;

depositing a metal layer on a substrate within the processing chamber, the metal layer comprising oxygen;

exposing a surface of the metal layer to a non-oxidizing plasma comprising hydrogen, while a first biasing voltage is applied to the substrate; and

exposing the exposed surface of the metal layer to a plasma comprising nitrogen, while a second biasing voltage is applied to the substrate.

2. The method of claim 1, wherein the first biasing voltage is between about 175 V and about 250 V, and the second biasing voltage is between about 175 V and about 250 V.

3. The method of claim 1, wherein the exposed surface of the metal layer is not exposed to air after being exposed to the non-oxidizing plasma comprising hydrogen and before being exposed to the plasma comprising nitrogen.

4. The method of claim 1, wherein the metal layer comprises nitrogen.

5. The method of claim 1, wherein the plasma comprising nitrogen consists essentially of ammonia, nitrogen gas, and argon.

6. The method of claim 1, further comprising, prior to depositing the metal layer, performing a surface preparation process on a surface of the substrate.

7. The method of claim 1, wherein the non-oxidizing plasma comprising hydrogen consists essentially of hydrogen gas and argon gas.

8. The method of claim 1, further comprising exposing the metal layer to the non-oxidizing plasma comprising hydrogen and the plasma comprising nitrogen a second time.

9. The method of claim 1, wherein the oxygen-free plasma treatment process is performed on the processing chamber component when the substrate is not disposed within the processing chamber.

10. A method of forming a structure in a semiconductor device, comprising:

performing an oxygen-free plasma treatment process on a processing chamber component disposed within a processing chamber in which the processing chamber component is exposed to a non-oxidizing plasma comprising hydrogen;

depositing a metal layer on a substrate within the processing chamber, the metal layer comprising oxygen;

exposing a surface of the metal layer to a non-oxidizing plasma comprising hydrogen, while a first bias is applied to the substrate;

exposing the exposed surface of the metal layer to a plasma comprising nitrogen, while a second bias is applied to the substrate; and

performing a thermal anneal process on the metal layer.

11. The method of claim 10, wherein the first biasing voltage is between about 175 V and about 250 V, and the second biasing voltage is between about 175 V and about 250 V.

12. The method of claim 10, wherein the exposed surface of the metal layer is not exposed to air after being exposed to the non-oxidizing plasma comprising hydrogen and before being exposed to the plasma comprising nitrogen.

13. The method of claim 10, wherein the metal layer comprises nitrogen.

14. The method of claim 10, wherein the plasma comprising nitrogen consists essentially of ammonia, nitrogen gas, and argon.

15. The method of claim 10, further comprising, prior to depositing the metal layer, performing a surface preparation process on a surface of the substrate.

16. The method of claim 10, wherein the non-oxidizing plasma comprising hydrogen consists essentially of hydrogen gas and argon gas.

17. The method of claim 10, further comprising exposing the metal layer to the non-oxidizing plasma comprising hydrogen and the plasma comprising nitrogen a second time.

18. The method of claim 10, wherein the oxygen-free plasma treatment process is performed on the processing chamber component when the substrate is not disposed within the processing chamber.

19. A method of forming a structure in a semiconductor device, the method comprising:

performing an oxygen-free plasma treatment process on a processing chamber component disposed within a processing chamber in which the processing chamber component is exposed to a non-oxidizing plasma comprising hydrogen;

depositing a metal layer on a substrate within the processing chamber, the metal layer comprising oxygen;

exposing a surface of the metal layer to a non-oxidizing plasma comprising hydrogen, while a first biasing voltage is applied to the substrate; and

exposing the exposed surface of the metal layer to a plasma comprising nitrogen and having an RF power of about 100 W to about 2,500 W, while a second biasing voltage is applied to the substrate.

20. The method of claim 19, wherein the first biasing voltage is between about 175 V and about 250 V, and the second biasing voltage is between about 175 V and V to about 250 V, and the RF power is about 1,000 W to about 2,000 W.