Methods for improving the cracking resistance of low-k dielectric materials

• US 7,381,662 B1
• Filed: 03/14/2006
• Issued: 06/03/2008
• Est. Priority Date: 03/11/2004
• Status: Expired due to Fees

• Current Assignee: Novellus Systems Incorporated (Lam Research Corporation)
• Original Assignee: Novellus Systems Incorporated (Lam Research Corporation)
• Inventors: Lu, Brian, Fu, Haiying, Wang, Feng, Niu, Dong
• Primary Examiner(s): Lee; Calvin
• Application Number:
  US11/376,510
• Time in Patent Office: 812 Days
• Field of Search: 438/410, 438/707, 438795-798, 428/304, 428/446
• US Class Current: 438/795
• CPC Class Codes: C23C 16/401 containing silicon
• CPC Class Codes: C23C 16/56 After-treatment
• CPC Class Codes: H01L 21/02126 the material containing Si, O, and at least one of H, N, C, F, or other non-metal elements, e.g. SiOC, SiOC:H or SiONC
• CPC Class Codes: H01L 21/02203 the layer being porous
• CPC Class Codes: H01L 21/02216 the compound being a molecule comprising at least one silicon-oxygen bond and the compound having hydrogen or an organic group attached to the silicon or oxygen, e.g. a siloxane
• CPC Class Codes: H01L 21/02274 in the presence of a plasma [PECVD]
• CPC Class Codes: H01L 21/0234 treatment by exposure to a plasma
• CPC Class Codes: H01L 21/02348 treatment by exposure to UV light
• CPC Class Codes: H01L 21/02351 treatment by exposure to corpuscular radiation, e.g. exposure to electrons, alpha-particles, protons or ions
• CPC Class Codes: H01L 21/3105 After-treatment
• CPC Class Codes: H01L 21/31633 Deposition of carbon doped silicon oxide, e.g. SiOC
• CPC Class Codes: H01L 21/31695 Deposition of porous oxides or porous glassy oxides or oxide based porous glass

Abstract

Methods for improving the mechanical properties of a CDO film are provided. The methods involve, for instance, providing either a dense CDO film or a porous CDO film in which the porogen has been removed followed by curing the CDO film at an elevated temperature using either a UV light treatment, an e-beam treatment, or a plasma treatment such that the curing improves the mechanical toughness of the CDO dielectric film.

Claims

1. A method for improving the mechanical properties of a CDO film comprising:

providing either a dense CDO film or a porous CDO film in which the porogen has been removed wherein the CDO film includes carbon-carbon triple bonds; and

curing the CDO film using an e-beam treatment whereby the curing improves the mechanical toughness of the CDO dielectric film.

2. The method of claim 1, wherein the energy of the e-beam is between about 1-50 keV.

3. The method of claim 1, wherein the energy of the e-beam is between about 10 keV and 30 keV.

4. The method of claim 1, wherein the e-beam dosage is between about 0.02 to 3 mC/cm².

5. The method of claim 1, wherein the duration of the e-beam treatment is between about 1-8 minutes.

6. The method of claim 1, wherein the duration of the e-beam treatment is between about 10 seconds and ½

hour.

7. The method of claim 1, wherein the substrate is maintained at a temperature of between about 150-400°

C. during e-beam treatment.

8. The method of claim 1, wherein the substrate is maintained at a temperature of between about 20-400°

C. during the e-beam treatment.

9. The method of claim 1, wherein the CDO film produced has a dielectric constant between about 2.0-3.5.

10. The method of claim 1, wherein the CDO film is a dense CDO film.

11. A method for improving the mechanical properties of a CDO film comprising:

providing either a dense CDO film or a porous CDO film in which the porogen has been removed wherein the CDO film includes carbon-carbon triple bonds; and

curing the CDO film using a plasma treatment whereby the curing improves the mechanical toughness of the CDO dielectric film.

12. The method of claim 11, wherein the intensity of the plasma is between about 1000-3000 W for six 200 mm wafers.

13. The method of claim 11, wherein the intensity of the plasma is between about 0.1 and 10 W/cm².

14. The method of claim 11, wherein the plasma is generated using hydrogen gas.

15. The method of claim 11, wherein the deposition chamber is maintained at a pressure of between about 0.1 and 20 Torr during the plasma treatment.

16. The method of claim 11, wherein the duration of the plasma treatment is between about 1-8 minutes.

17. The method of claim 11, wherein the duration of the plasma treatment is between about 3 seconds and ½

hour.

18. The method of claim 11, wherein the substrate is maintained at a temperature of between about 150-400°

C. during the plasma treatment.

19. The method of claim 11, wherein the substrate is maintained at a temperature of between about 20-400°

C. during the plasma treatment.

20. The method of claim 11, wherein the CDO film is a dense CDO film.