Method of improving interlayer adhesion

• US 20040175929A1
• Filed: 03/07/2003
• Published: 09/09/2004
• Est. Priority Date: 03/07/2003
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Xia, Li-Qun, Nguyen, Son Van, Venkataraman, Shankar, Schmitt, Francimar Campana
• Granted Patent: US 6,913,992 B2
• Time in Patent Office: Days
• US Class Current: 438/628
• CPC Class Codes: C23C 16/0272 Deposition of sub-layers, e.g. to promote the adhesion of the main coating
• CPC Class Codes: C23C 16/30 Deposition of compounds, mixtures or solid solutions, e.g. borides, carbides, nitrides
• CPC Class Codes: C23C 16/325 Silicon carbide
• CPC Class Codes: C23C 16/505 using radio frequency discharges
• 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 21/02167 the material being a silicon carbide not containing oxygen, e.g. SiC, SiC:H or silicon carbonitrides H01L21/02126 and H01L21/0214 take precedence
• CPC Class Codes: H01L 21/022 the layer being a laminate, i.e. composed of sublayers, e.g. stacks of alternating high-k metal oxides adhesion layers or buffer layers H01L21/02304, H01L21/02362
• CPC Class Codes: H01L 21/02203 the layer being porous
• CPC Class Codes: H01L 21/02211 the compound being a silane, e.g. disilane, methylsilane or chlorosilane
• CPC Class Codes: H01L 21/02274 in the presence of a plasma [PECVD]
• CPC Class Codes: H01L 21/0228 deposition by cyclic CVD, e.g. ALD, ALE, pulsed CVD
• 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 21/0234 treatment by exposure to a plasma
• 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 21/31058 of organic layers
• CPC Class Codes: H01L 21/3121 Layers comprising organo-silicon compounds
• CPC Class Codes: H01L 21/3148 Silicon Carbide layers
• 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 21/76825 : by exposing the layer to particle radiation, e.g. ion implantation, irradiation with UV light or electrons etc. plasma treatment H01L21/76826
• CPC Class Codes: H01L 21/76826 : by contacting the layer with gases, liquids or plasmas
• CPC Class Codes: H01L 21/76829 : characterised by the formation of thin functional dielectric layers, e.g. dielectric etch-stop, barrier, capping or liner layers
• CPC Class Codes: H01L 21/76832 : Multiple layers
• CPC Class Codes: H01L 21/76835 : Combinations of two or more different dielectric layers having a low dielectric constant H01L21/76832 takes precedence

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 depositing a barrier layer on the substrate, wherein the barrier layer comprises silicon and carbon and has a dielectric constant less than 4, depositing a dielectric initiation layer adjacent the barrier layer, and depositing a first dielectric layer adjacent the dielectric initiation layer, wherein the dielectric layer comprises silicon, oxygen, and carbon and has a dielectric constant of about 3 or less.

Claims

1. A method for processing a substrate, comprising:

depositing a barrier layer on the substrate, wherein the barrier layer comprises silicon and carbon and has a dielectric constant less than 4;

depositing a dielectric initiation layer adjacent the barrier layer; and

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

2. The method of claim 1, wherein the dielectric initiation layer is deposited by introducing a processing gas comprising an organosilicon compound, a carbon-containing oxidizing compound, and a nitrating compound into a processing chamber, and reacting the processing gas to deposit the dielectric initiation layer.

3. The method of claim 2, wherein the carbon-containing oxidizing compound is selected from the group of an oxygen-containing organosilicon compound, carbon dioxide, carbon monoxide, and combinations thereof.

4. The method of claim 3, wherein the organosilicon compound is selected from the group of trimethylsilane, 2,4,6,8-tetramethylcyclotetrasiloxane, octamethylcyclotetrasiloxane, and combinations thereof.

5. The method of claim 2, wherein the nitrogen-containing compound is selected from the group of ammonia, ammonia derivatives, hydrazine, a mixture of hydrogen and nitrogen, and combinations thereof.

6. The method of claim 2, wherein the reacting processing gas comprises generating a plasma by a single-frequency RF power source.

7. The method of claim 2, wherein the reacting processing gas comprises generating a plasma by a dual-frequency RF power source.

8. The method of claim 2, wherein the processing gas further comprises an inert gas.

9. The method of claim 1, further comprising treating the deposited dielectric initiation layer to an e-beam curing technique prior to subsequent processing.

10. The method of claim 9, wherein the e-beam curing technique applied a dosage of 400 μ

C/cm² between about 6 kV and about 8 kV to the dielectric initiation layer.

11. The method of claim 1, wherein the dielectric initiation layer comprises silicon, oxygen, and carbon, and is deposited at a first temperature, and wherein the first dielectric layer is deposited at a second temperature less than the first temperature.

12. The method of claim 1, wherein the dielectric initiation layer is deposited by introducing a first processing gas comprising an organosilicon compound and an oxidizing compound into a processing chamber at a first organosilicon flow rate and reacting the first processing gas, the first dielectric layer is deposited by introducing a second processing gas comprising an organosilicon compound and an oxidizing compound into a processing chamber at a second organosilicon flow rate and reacting the second processing gas, wherein the second organosilicon flow rate is greater than the first organosilicon flow rate.

13. The method of claim 1, wherein the dielectric initiation layer comprises silicon, oxygen, and carbon, and is deposited at a first deposition rate, and wherein the dielectric layer is deposited at a second deposition rate less than the first deposition rate.

14. A method for processing a substrate, comprising:

depositing a first dielectric layer on the substrate, wherein the first dielectric layer comprises silicon and carbon and is deposited by a process comprising introducing a processing gas having an organosilicon compound and reacting the processing gas to deposit the first dielectric layer;

reducing the carbon content at a surface portion of the first dielectric layer; and

then

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

15. The method of claim 14, wherein the reducing of the carbon content at a surface portion of the first dielectric layer comprises forming an oxidized surface on the first dielectric layer.

16. The method of claim 15, wherein the forming of the oxidized surface of the first dielectric layer comprises exposing the first dielectric layer to a nitrogen-free oxidizing plasma.

17. The method of claim 15, wherein the forming of the oxidized surface of the first dielectric layer comprises introducing an oxygen-containing compound to the processing gas.

18. The method of claim 14, wherein depositing the second dielectric layer comprises introducing a processing gas comprising an organosilicon compound and an oxidizing compound, and reacting the processing gas to deposit the first dielectric layer, wherein the reducing of the carbon content at a surface portion of the first dielectric layer comprises introducing a processing gas comprising an organosilicon compound, a carbon-containing oxidizing compound, and a nitrating compound into a processing chamber, and reacting the processing gas to deposit a dielectric material at the surface of the barrier layer

19. The method of claim 14, further comprising treating the first dielectric layer to an e-beam curing technique prior to subsequent processing.

20. A method for processing a substrate, comprising:

depositing a barrier layer on the substrate, wherein the barrier layer is deposited by introducing a processing gas comprising an organosilicon compound into a processing chamber and reacting the processing gas;

depositing a barrier layer termination layer adjacent the barrier layer, wherein the barrier layer is deposited by introducing a processing gas comprising an organosilicon compound and an oxidizing compound into a processing chamber and reacting the processing gas; and

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

21. The method of claim 20, further comprising treating the barrier layer termination layer to an e-beam curing technique, prior to subsequent processing.

22. The method of claim 21, wherein the e-beam curing technique applied a dosage of 400 μ

C/cm² between about 6 kV and about 8 kV to the dielectric initiation layer.

23. The method of claim 20, further comprising exposing the barrier layer termination layer to a nitrogen-free oxidizing plasma prior to subsequent processing.