Method of depositing low K films

• US 20030162410A1
• Filed: 02/25/2003
• Published: 08/28/2003
• Est. Priority Date: 02/11/1998
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Lu, Yung-Cheng, Xia, Li-Qun, Yieh, Ellie, Yau, Wai-Fan, Lee, Ju-Hyung, Liu, Kuowei, Huang, Tzu-Fang, Moghadam, Farhad K., Willecke, Ralf B., Ma, Yeming Jim, Cheung, David W.
• Granted Patent: US 6,806,207 B2
• Time in Patent Office: Days
• US Class Current: 438/780
• CPC Class Codes: C23C 16/045 Coating cavities or hollow spaces, e.g. interior of tubes; Infiltration of porous substrates
• 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 21/02208 the precursor containing a compound comprising Si
• 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 21/0228 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 21/02362 formation of intermediate layers, e.g. capping layers or diffusion barriers
• CPC Class Codes: H01L 21/31612 on a silicon body
• 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 21/76808 involving intermediate temporary filling with material
• 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 21/76835 Combinations of two or more different dielectric layers having a low dielectric constant H01L21/76832 takes precedence
• CPC Class Codes: H01L 2221/1031 Dual damascene by forming vias in the via-level dielectric prior to deposition of the trench-level dielectric

Abstract

A silicon oxide layer is produced by plasma enhanced decomposition of an organosilicon compound to deposit films having a carbon content of at least 1% by atomic weight. An optional carrier gas may be introduced to facilitate the deposition process at a flow rate less than or equal to the flow rate of the organosilicon compounds. An oxygen rich surface may be formed adjacent the silicon oxide layer by temporarily increasing oxidation of the organosilicon compound.

Claims

1. A process for depositing a low dielectric constant film, comprising decomposing one or more organosilicon compounds selected from a group consisting of octamethylcyclotetrasiloxane, 2,4,6,8-tetramethylcyclotetrasiloxane, 1,3-dimethyldisiloxane, 1,1,3,3-tetramethyldisiloxane, hexamethyldisiloxane, 1,3-bis(silanomethylene)disiloxane, bis(1-methyldisiloxanyl)methane, 2,2-bis(1-methyldisiloxanyl)propane, 2,4,6,8,10-pentamethylcyclopentasiloxane, 1,3,5,7-tetrasilano-2,6-dioxy-4,8-dimethylene, 2,4,6-trisilanetetrahydropyran, and 2,5-disilanetetrahydrofuran, and at a RF power density of at least about 0.03 W/cm² to deposit a film comprising silicon, oxygen, and a carbon content of at least 1% by atomic weight.

2. The process of claim 1, wherein the low dielectric constant film has an atomic ratio of carbon to silicon (C:

Si) of less than about 1;

1.

3. The process of claim 1, wherein the low dielectric constant film has an atomic ratio of carbon to silicon (C:

Si) between about 1;

4 and about 3;

4.

4. The process of claim 1, wherein the one or more organosilicon compounds have a flow rate of between about 5 sccm and about 1000 sccm.

5. The process of claim 1, wherein the one or more organosilicon compounds are decomposed in the presence of a carrier gas.

6. The process of claim 1, wherein the one or more organosilicon compounds comprise 2,4,6,8-tetramethylcyclotetrasiloxane.

7. The process of claim 1, wherein the low dielectric constant film is deposited at a temperature of between about 10°

C. and about 500°

C.

8. The process of claim 5, wherein the carrier gas has a flow rate less than or equal to a combined flow rate of the one or more organosilicon compounds.

9. The process of claim 1, further comprising forming an oxide rich surface adjacent the low dielectric constant film.

10. A process for depositing a low dielectric constant film, consisting essentially of decomposing one or more organosilicon compounds selected from the group consisting of octamethylcyclotetrasiloxane, 2,4,6,8-tetramethylcyclotetrasiloxane, 1,3-dimethyldisiloxane, 1,1,3,3-tetramethyidisiloxane, hexamethyidisiloxane, 1,3-bis(silanomethylene)disiloxane, bis(1-methyldisiloxanyl)methane, 2,2-bis(1-methyidisiloxanyl)propane, 2,4,6,8,10-pentamethylcyclopentasiloxane, 1,3,5,7-tetrasilano-2,6-dioxy-4,8-dimethylene, 2,4,6-trisilanetetrahydropyran, and 2,5-disilanetetrahydrofuran at a power density of greater than about 0.03 W/cm², and a carrier gas flow rate less than or equal to a combined flow rate of the one or more organosilicon compounds at conditions sufficient to deposit a film comprising silicon, oxygen, and carbon and an atomic ratio of carbon to silicon (C:

Si) of greater than or equal to about 1;

9.

11. The process of claim 10, wherein the atomic ratio of carbon to silicon (C:

Si) is less than about 1;

1 in the film.

12. The process of claim 10, wherein the atomic ratio of carbon to silicon (C:

Si) is between about 1;

4 and about 3;

4 in the film.

13. The process of claim 10, wherein the one or more organosilicon compounds comprise 2,4,6,8-tetramethylcyclotetrasiloxane.

14. The process of claim 10, further comprising forming an oxide rich surface adjacent the low dielectric constant film.

15. A process for depositing a low dielectric constant film, comprising decomposing octamethylcyclotetrasiloxane, 2,4,6,8-tetramethylcyclotetrasiloxane, or combinations thereof at a power density ranging between about 0.9 W/cm² and about 3.2 W/cm² at conditions sufficient to deposit a film having an atomic ratio of carbon to silicon (C:

Si) of between about 1;

9 and less than about 1;

1.

16. The process of claim 15, wherein the atomic ratio of carbon to silicon (C:

Si) is between about 1;

4 and about 3;

4 in the film.

17. The process of claim 15, wherein the low dielectric constant film is deposited at a temperature of between about 300°

C. and about 450°

C.

18. The process of claim 15, wherein the low dielectric constant film is deposited at a processing chamber pressure of between about 0.2 Torr and about 20 Torr.

19. The process of claim 15, further comprising a carrier gas having a flow rate less than or equal to a total flow rate of the octamethylcyclotetrasiloxane and 2,4,6,8-tetramethylcyclotetrasiloxane.

20. The process of claim 15, further comprising forming an oxide rich surface adjacent the low dielectric constant film.