LOW DIELECTRIC (LOW K) BARRIER FILMS WITH OXYGEN DOPING BY PLASMA-ENHANCED CHEMICAL VAPOR DEPOSITION (PECVD)

• US 20090053902A1
• Filed: 10/21/2008
• Published: 02/26/2009
• Est. Priority Date: 12/14/2001
• Status: Active Grant

• 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
• Granted Patent: US 7,745,328 B2
• Time in Patent Office: Days
• US Class Current: 438/761
• 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 on 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.

2. The method of claim 1, 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.

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 comprises organosilicon compound having 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 on 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. A method of processing a substrate, comprising:

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

forming a plurality of layers on the substrate, comprising;

a first dielectric layer having barrier properties and comprising silicon, carbon, and nitrogen;

a second dielectric layer having barrier properties and comprising silicon and carbon, wherein the second dielectric layer is nitrogen free; and

a third dielectric layer comprising silicon, oxygen, and carbon, wherein the third dielectric layer has a dielectric constant of about 3 or less.

11. The method of claim 10, wherein at least one of the first or the second dielectric layer is a barrier layer.

12. The method of claim 10, wherein the second dielectric layer is formed by reacting a processing gas comprising a carbon and oxygen containing compound and an oxygen-free organosilicon compound.

13. The method of claim 12, wherein the oxygen-free organosilicon compound comprises an organosilicon compound having 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.

14. The method of claim 13, wherein the oxygen-free organosilicon compound comprises trimethylsilane, tetramethylsilane, or both.

15. The method of claim 10, wherein the first dielectric layer and the second dielectric layer are formed without breaking vacuum.

16. The method of claim 12, wherein the processing gas further comprises an inert gas.

17. The method of claim 16, wherein the inert gas is selected from the group consisting of helium, argon, and combinations thereof.

18. The method of claim 12, wherein the processing gas comprises carbon dioxide, helium, and trimethylsilane.

19. The method of claim 10, wherein forming the second dielectric 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.

20. A method of processing a substrate, comprising:

providing a substrate having conductive features formed therein to a processing chamber;

forming a nitrogen containing layer on the substrate;

forming an oxygen-doped silicon carbide layer on the nitrogen-containing layer; and

forming a low-k dielectric layer on the oxygen-doped silicon carbide layer, wherein the oxygen-doped silicon carbide layer is formed by providing trimethylsilane to the 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.