Adhesion improvement for low k dielectrics

• US 20060189162A1
• Filed: 04/18/2006
• Published: 08/24/2006
• Est. Priority Date: 03/15/2004
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Sugiarto, Jerry, Xia, Li-qun, Park, Sohyun, M'Saad, Hichem, Cui, Zhenjiang, Huang, Tzu-Fang, Lee, Peter Wai-Man, Huang, Lihua Li, Sugiarto, Dian
• Granted Patent: US 7,459,404 B2
• Time in Patent Office: Days
• US Class Current: 438/780
• CPC Class Codes: C23C 16/02 Pretreatment of the material to be coated C23C16/04 takes precedence
• CPC Class Codes: C23C 16/325 Silicon carbide
• CPC Class Codes: C23C 16/401 containing silicon
• 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 21/02211 the compound being a silane, e.g. disilane, methylsilane or chlorosilane
• 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 21/02304 formation of intermediate layers, e.g. buffer layers, layers to improve adhesion, lattice match or diffusion barriers
• CPC Class Codes: H01L 21/31633 Deposition of carbon doped silicon oxide, e.g. SiOC
• CPC Class Codes: H01L 21/76801 characterised by the formation and the after-treatment of the dielectrics, e.g. smoothing
• CPC Class Codes: H01L 21/7681 involving one or more buried masks
• CPC Class Codes: H01L 21/76826 by contacting the layer with gases, liquids or plasmas
• CPC Class Codes: H01L 21/76832 Multiple layers

Abstract

Methods are provided for processing a substrate for depositing an adhesion layer having a low dielectric constant between two low k dielectric layers. In one aspect, the invention provides a method for processing a substrate including introducing an organosilicon compound and an oxidizing gas at a first ratio of organosilicon compound to oxidizing gas into the processing chamber, generating a plasma of the oxidizing gas and the organosilicon compound to form an initiation layer on a barrier layer comprising at least silicon and carbon, introducing the organosilicon compound and the oxidizing gas at a second ratio of organosilicon compound to oxidizing gas greater than the first ratio into the processing chamber, and depositing a first dielectric layer adjacent the dielectric initiation layer.

Claims

1. A method for processing a substrate, comprising:

positioning the substrate in a processing chamber, wherein the substrate has a barrier layer comprising at least silicon and carbon;

introducing a pretreatment gas into the processing chamber, wherein the pretreatment gas comprises an oxidizing gas, an inert gas, or combinations thereof;

generating a plasma of the pretreatment gas to modify a surface of the barrier layer;

introducing an organosilicon compound and an oxidizing gas at a first ratio of organosilicon compound to oxidizing gas; and

depositing a first dielectric layer on the substrate, wherein the dielectric layer comprises silicon, oxygen, and carbon.

2. The method of claim 1, wherein the barrier layer further comprises oxygen or nitrogen.

3. The method of claim 1, wherein the organosilicon compound is selected from the group of trimethylsilane, 1,3,5,7-tetramethylcyclotetrasiloxane, octamethylcyclotetrasiloxane, and combinations thereof, and the oxidizing gas is selected from the group of oxygen, ozone, carbon monoxide, carbon dioxide, nitrous oxide, and combinations thereof.

4. The method of claim 1, further comprising:

introducing the organosilicon compound and the oxidizing gas at a second ratio of organosilicon compound to oxidizing gas smaller than the first ratio into the processing chamber; and

generating a plasma of oxidizing gas and the organosilicon compound to form an initiation layer on the barrier layer.

5. The method of claim 4, wherein the depositing the initiation layer comprises generating a plasma by a dual-frequency RF power source.

6. The method of claim 1, wherein the depositing the first dielectric layer comprises generating a plasma by a dual-frequency RF power source.

7. The method of claim 4, wherein the second ratio of the organosilicon compound to the oxidizing gas comprises a ratio of about 1:

1 and the first ratio of the organosilicon compound to the oxidizing gas comprises a ratio greater than or equal to about 10;

1.

8. The method of claim 1, further comprising introducing an inert gas with the organosilicon compound and the oxidizing gas.

9. The method of claim 1, wherein the first dielectric layer has a dielectric constant of about 3 or less.

10. A method for processing a substrate, comprising:

positioning the substrate in a processing chamber, wherein the substrate has a barrier layer comprising silicon, nitrogen, and carbon;

introducing an inert gas into the processing chamber;

generating a first plasma from a single-frequency RF power source to modify a surface of the barrier layer;

introducing an organosilicon compound and an oxidizing gas at a ratio of greater than or equal to about 10;

1 into the processing chamber; and

depositing a first dielectric layer on the substrate, wherein the dielectric layer comprises silicon, oxygen, and carbon and has a dielectric constant of about 3 or less.

11. The method of claim 10, further comprising:

introducing the organosilicon compound and the oxidizing gas in a ratio of about 1;

1 into the processing chamber; and

generating a second plasma from a dual-frequency RF power source to form an initiation layer on the barrier layer;

12. The method of claim 10, wherein the inert gas comprises helium, argon, or combinations thereof.

13. The method of claim 10, wherein the organosilicon compound is selected from the group of trimethylsilane, 1,3,5,7-tetramethylcyclotetrasiloxane, octamethylcyclotetrasiloxane, and combinations thereof, and the oxidizing gas is selected from the group of oxygen, ozone, carbon monoxide, carbon dioxide, nitrous oxide, and combinations thereof.

14. A method for processing a substrate, comprising:

positioning the substrate in a processing chamber, wherein the substrate has a barrier layer comprising at least silicon and carbon;

introducing an oxidizing gas into the processing chamber;

generating a plasma of the oxidizing gas and treating a surface of the barrier layer;

introducing an organosilicon compound at a first flow rate;

depositing a first dielectric layer on the substrate from the oxidizing gas and the organosilicon compound, wherein the dielectric layer comprises silicon, oxygen, and carbon and has a dielectric constant of about 3 or less.

15. The method of claim 14, further comprising,

prior to depositing the first dielectric layer, introducing the organosilicon compound at a second flow rate smaller than the first flow rate;

and

depositing an initiation layer on the barrier layer from the oxidizing gas and the organosilicon compound.

16. The method of claim 14, wherein the barrier layer further comprises oxygen or nitrogen.

17. The method of claim 14, wherein the organosilicon compound is selected from the group of trimethylsilane, 1,3,5,7-tetramethylcyclotetrasiloxane, octamethylcyclotetrasiloxane, and combinations thereof, and the oxidizing gas is selected from the group of oxygen, ozone, carbon monoxide, carbon dioxide, nitrous oxide, and combinations thereof.

18. The method of claim 14, wherein the generating the plasma of the oxidizing gas comprises generating a plasma by a single-frequency RF power source and the depositing the initiation layer comprises generating a plasma by a dual-frequency RF power source.

19. The method of claim 14, wherein an inert gas is introduced with the organosilicon compound.

20. The method of claim 15, wherein the depositing the initiation layer comprises the organosilicon compound and oxidizing gas present in a ratio of about 1:

1, and the depositing the first dielectric layer comprises the organosilicon compound and oxidizing gas present in a ratio of greater than or equal to about 10;

1.