COPPER OXIDE REMOVAL TECHNIQUES

• US 20120289049A1
• Filed: 05/10/2011
• Published: 11/15/2012
• Est. Priority Date: 05/10/2011
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Nguyen, Victor, Shek, Mei-Yee, Balseanu, Mihaela, Xia, Li-Qun, Witty, Derek R., YE, WEIFENG
• Granted Patent: US 8,758,638 B2
• Time in Patent Office: Days
• US Class Current: 438/694
• CPC Class Codes: H01L 21/02074 the processing being a planarization of conductive layers
• CPC Class Codes: H01L 21/76883 Post-treatment or after-treatment of the conductive material

Abstract

A method for the removal of copper oxide from a copper and dielectric containing structure of a semiconductor chip is provided. The copper and dielectric containing structure may be planarized by chemical mechanical planarization (CMP) and treated by the method to remove copper oxide and CMP residues. Annealing in a hydrogen (H₂) gas and ultraviolet (UV) environment removes copper oxide, and a pulsed ammonia plasma removes CMP residues.

Claims

1. A method of removing copper oxide from a copper and dielectric containing structure, comprising:

exposing the copper and dielectric containing structure to a hydrogen (H₂) gas and ultraviolet (UV) radiation concurrently; and

exposing the copper and dielectric containing structure to a pulsed ammonia plasma.

2. The method of claim 1, wherein the exposing the copper and dielectric containing structure to the hydrogen gas and ultraviolet radiation concurrently comprises:

positioning the copper and dielectric containing structure in a processing volume of a processing chamber;

flowing the hydrogen gas into the processing volume; and

engaging a source of UV radiation to expose the copper and dielectric containing structure to the UV radiation.

3. The method of claim 2, wherein the exposing the copper and dielectric containing structure to the hydrogen gas and ultraviolet radiation concurrently is conducted using a chamber pressure between 2 Torr and 10 Torr, a substrate temperature between 200°

C. and 400°

C., an UV irradiance power between 1000 W/m² and 2000 W/m², UV wavelengths between 200 nm and 400 nm, a hydrogen gas flow rate between 1000 sccm and 10,000 sccm, and an annealing treatment time between 1 second and 60 seconds.

4. The method of claim 1, wherein the exposing the copper and dielectric containing structure to the pulsed ammonia plasma comprises:

positioning the copper and dielectric containing structure in a processing volume of a processing chamber;

flowing an ammonia gas into the processing volume; and

forming the pulsed ammonia plasma from the ammonia gas.

5. The method of claim 4, wherein the pulsed ammonia plasma is formed by coupling RF power to the ammonia gas, and wherein the exposing the copper and dielectric containing structure to the pulsed ammonia plasma is conducted using a chamber pressure between 2 Torr and 4 Torr, a substrate temperature between 200°

C. and 400°

C., a RF power between 300 W and 1000 W, a RF power frequency between 300 kHz and 15 MHz, an ammonia gas flow rate between 1000 sccm and 3000 sccm, a pulse frequency between 1 Hz and 50 kHz.

6. The method of claim 4, wherein the ammonia gas is mixed with a nitrogen (N₂) carrier gas.

7. The method of claim 1, further comprising forming a diffusion barrier layer onto the copper and dielectric containing structure.

8. The method of claim 1, wherein exposing the copper and dielectric containing structure to the pulsed ammonia plasma occurs during a treatment time, and wherein the copper and dielectric containing structure is exposed to the pulsed ammonia plasma for a total time that is a percentage of the treatment time as defined by a duty cycle.

9. The method of claim 8, wherein the treatment time is between 10 seconds and 60 seconds, and wherein the duty cycle is between 5% and 50%.

10. The method of claim 8, wherein the total time is evenly divided into a number of divisions between 2 and 50000, and wherein the divisions are evenly distributed within the treatment time.

11. The method of claim 8, wherein the total time is evenly divided into a number of divisions between 2 and 50000, and wherein the divisions are evenly distributed within the treatment time.

12. The method of claim 1, wherein the copper and dielectric containing structure is exposed to the hydrogen gas and ultraviolet radiation concurrently prior to being exposed to the pulsed ammonia plasma.

13. A method of removing copper oxide from a copper and dielectric containing structure, comprising:

exposing the copper and dielectric containing structure to a hydrogen (H₂) gas and ultraviolet (UV) radiation concurrently, comprising;

positioning the copper and dielectric containing structure in a first processing volume of a first processing chamber;

flowing the hydrogen gas into the first processing volume; and

engaging a source of UV radiation to expose the copper and dielectric containing structure to the UV radiation; and

exposing the copper and dielectric containing structure to a pulsed ammonia plasma, comprising;

positioning the copper and dielectric containing structure in a second processing volume of a second processing chamber;

flowing an ammonia gas into the second processing volume; and

forming the pulsed ammonia plasma from the ammonia gas.

14. The method of claim 13, wherein the exposing the copper and dielectric containing structure to the hydrogen gas and ultraviolet radiation concurrently in the first processing volume is conducted using a chamber pressure between 2 Torr and 10 Torr, a substrate temperature between 200°

C. and 400°

C., an UV irradiance power between 1000 W/m² and 2000 W/m², UV wavelengths between 200 nm and 400 nm, a hydrogen gas flow rate between 1000 sccm and 10,000 sccm, and an annealing treatment time between 1 second and 60 seconds.

15. The method of claim 13, wherein the pulsed ammonia plasma is formed by coupling RF power to the ammonia gas, and wherein the exposing the copper and dielectric containing structure to the pulsed ammonia plasma in the second processing volume is conducted using a chamber pressure between 2 Torr and 4 Torr, a substrate temperature between 200°

C. and 400°

C., a RF power between 300 W and 1000 W, a RF power frequency between 300 kHz and 15 MHz, an ammonia gas flow rate between 1000 sccm and 3000 sccm, a pulse frequency between 1 Hz and 50 kHz.

16. The method of claim 13, wherein exposing the copper and dielectric containing structure to the pulsed ammonia plasma occurs during a treatment time, and wherein the copper and dielectric containing structure is exposed to the pulsed ammonia plasma for a total time that is a percentage of the treatment time as defined by a duty cycle.

17. The method of claim 16, wherein the treatment time is between 10 seconds and 60 seconds, and wherein the duty cycle is between 5% and 50%.

18. The method of claim 17, wherein the total time is evenly divided into a number of divisions between 2 and 50000, and wherein the divisions are evenly distributed within the treatment time.

19. The method of claim 17, wherein the total time is evenly divided into a number of divisions between 2 and 50000, and wherein the divisions are evenly distributed within the treatment time.

20. A method of removing copper oxide from a copper and dielectric containing structure, comprising:

exposing the copper and dielectric containing structure to a hydrogen (H₂) gas and ultraviolet (UV) radiation concurrently during an annealing treatment time; and

exposing the copper and dielectric containing structure to a pulsed ammonia plasma during a plasma treatment time, wherein the copper and dielectric containing structure is exposed to the pulsed ammonia plasma for a total time that is a percentage of the treatment time as defined by a duty cycle, and wherein the total time is divided into divisions distributed within the plasma treatment time.