Low dielectric (low k) barrier films with oxygen doping by plasma-enhanced chemical vapor deposition (PECVD)

• US 7,157,384 B2
• Filed: 12/22/2004
• Issued: 01/02/2007
• Est. Priority Date: 12/14/2001
• Status: Expired due to Term

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Xia, Li-Qun, Lang, Chi-I, Yim, Kang Sub, Lee, Peter Wai-Man, Tam, Melissa M., Sugiarto, Dian
• Primary Examiner(s): Brewster; William M.
• Application Number:
  US11/021,319
• Publication Number:
  US 20050130440A1
• Time in Patent Office: 741 Days
• Field of Search: 438/769, 438/786, 438/788, 438/789
• US Class Current: 438/769
• 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 16/401 containing silicon
• 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 21/02211 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 21/31116 by dry-etching
• CPC Class Codes: H01L 21/31138 by dry-etching
• CPC Class Codes: H01L 21/31144 using masks
• CPC Class Codes: H01L 21/312 Organic layers, e.g. photoresist H01L21/3105, H01L21/32 take precedence; photoresists per se G03C
• CPC Class Codes: H01L 21/3122 layers comprising polysiloxane compounds
• CPC Class Codes: H01L 21/3127 Layers comprising fluoro (hydro)carbon compounds, e.g. polytetrafluoroethylene
• 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 21/3185 of siliconnitrides
• CPC Class Codes: H01L 21/76807 for dual damascene structures
• 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 21/76828 : thermal treatment
• 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 21/76834 : formation of thin insulating films on the sidewalls or on top of conductors H01L21/76831 takes precedence

Abstract

Methods are provided for depositing a silicon carbide layer having significantly reduced current leakage. The silicon carbide layer may be a barrier layer or part of a barrier bilayer that also includes a barrier layer. Methods for depositing oxygen-doped silicon carbide barrier layers are also provided. The silicon carbide layer may be deposited by reacting a gas mixture comprising an organosilicon compound, an aliphatic hydrocarbon comprising a carbon-carbon double bond or a carbon-carbon triple bond, and optionally, helium in a plasma. Alternatively, the silicon carbide layer may be deposited by reacting a gas mixture comprising hydrogen or argon and an organosilicon compound in a plasma.

Claims

1. A method for processing a substrate, comprising:

providing a substrate having conductive features formed in a dielectric material to a processing chamber;

depositing a first barrier layer comprising silicon, carbon, and nitrogen on the substrate;

depositing a second barrier layer contacting at least a portion of the first barrier layer, wherein the second barrier layer is a nitrogen free dielectric layer comprising silicon and carbon and deposited by reading a processing gas comprising a carbon and oxygen containing compound and an oxygen-free organosilicon compound.

2. The method of claim 1, further comprising depositing a dielectric layer contacting the second barrier layer, wherein the dielectric layer comprises silicon, oxygen, and carbon and has a dielectric constant of about 3 or less.

3. The method of claim 1, wherein the compound comprising oxygen and carbon is selected from the group of carbon dioxide, carbon monoxide, an oxygen-containing organosilicon compound, and combinations thereof.

4. The method of claim 1, wherein the oxygen-free organosilicon compound has the formula SiH_a(CH₃)_b(C₆H₅)_c, wherein a is 0 to 3, b is 0 to 3, and c is 1 to 4.

5. The method of claim 4, wherein the oxygen-free organosilicon compound comprises trimethylsilane, tetramethylsilane, or both.

6. The method of claim 1, wherein the processing gas further comprises an inert gas selected from the group of helium, argon, and combinations thereof.

7. The method of claim 6, wherein the processing gas comprises carbon dioxide, helium, and trimethylsilane.

8. The method of claim 1, wherein the first barrier layer and the second barrier layer are deposited in situ in the same processing chamber or same processing system without breaking vacuum.

9. The method of claim 1, wherein the depositing a second barrier layer contacting the first barrier layer comprises supplying trimethylsilane to a processing chamber at a flow rate between about 50 sccm and about 300 sccm, supplying carbon dioxide at a flow rate between about 100 sccm and about 800 sccm, supplying helium at a flow rate between about 200 sccm and about 800 sccm, maintaining a substrate temperature between about 300°

C. and about 400°

C., maintaining a chamber pressure between about 2 Torr and about 5 Torr, and applying a RF power of between about 200 watts and about 500 watts.

10. The method of claim 1, further comprising:

depositing a photoresist layer directly on the second barrier layer.

11. A method for processing a substrate, comprising:

providing the substrate to a processing chamber; and

depositing a barrier bilayer, wherein the barrier bilayer comprises;

a first barrier layer comprising silicon, carbon, and nitrogen on the substrate; and

a second barrier layer contacting at least a portion of the first barrier layer, wherein the second barrier layer is a nitrogen free dielectric layer comprising silicon and carbon and deposited by reacting a processing gas comprising a carbon and oxygen containing compound and an oxygen-free organosilicon compound.

12. The method of claim 11, further comprising depositing a dielectric layer adjacent the second barrier layer, wherein the dielectric layer comprises silicon, oxygen, and carbon and has a dielectric constant of about 3 or less.

13. The method of claim 11, wherein the compound comprising oxygen and carbon is selected from the group of carbon dioxide, carbon monoxide, an oxygen-containing organosilicon compound, and combinations thereof.

14. The method of claim 11, wherein the oxygen-free organosilicon compound has the formula SiH_a(CH₃)_b(C₆H₅)_c, wherein a is 0 to 3, b is 0 to 3, and c is 1 to 4.

15. The method of claim 14, wherein the oxygen-free organosilicon compound comprises trimethylsilane, tetramethylsilane, or both.

16. The method of claim 11, wherein the processing gas further comprises an inert gas selected from the group of helium, argon, and combinations thereof.

17. The method of claim 16, wherein the processing gas comprises carbon dioxide, helium, and trimethylsilane.

18. The method of claim 11, wherein the first barrier layer and the second barrier layer are deposited in situ in the same processing chamber or same processing system without breaking vacuum.

19. The method of claim 11, wherein the second barrier layer is deposited by supplying trimethylsilane to a processing chamber at a flow rate between about 50 sccm and about 300 sccm, supplying carbon dioxide at a flow rate between about 100 sccm and about 800 sccm, supplying helium at a flow rate between about 200 sccm and about 800 sccm, maintaining a substrate temperature between about 300°

C. and about 400°

C., maintaining a chamber pressure between about 2 Torr and about 5 Torr, and applying a RF power of between about 200 watts and about 500 watts.

20. The method of claim 11, further comprising:

depositing a photoresist layer directly on the second barrier layer.