Method for forming ultra low k films using electron beam

• US 20040101633A1
• Filed: 11/22/2002
• Published: 05/27/2004
• Est. Priority Date: 05/08/2002
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Xia, Li-Qun, Nemani, Srinivas D., Zheng, Yi, Yim, Kang Sub, Hollar, Eric
• Granted Patent: US 7,060,330 B2
• Time in Patent Office: Days
• US Class Current: 427/551
• CPC Class Codes: B05D 1/60 Deposition of organic layers from vapour phase vapour phase deposition in general C23C14/00, C23C16/00
• CPC Class Codes: B05D 3/068 using ionising radiations (gamma, X, electrons)
• CPC Class Codes: C23C 16/401 containing silicon
• 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 21/02216 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 21/02351 treatment by exposure to corpuscular radiation, e.g. exposure to electrons, alpha-particles, protons or ions
• CPC Class Codes: H01L 21/31058 of organic layers
• CPC Class Codes: H01L 21/3121 Layers comprising organo-silicon compounds
• CPC Class Codes: H01L 21/3122 layers comprising polysiloxane compounds
• CPC Class Codes: H01L 21/3125 layers comprising silazane compounds
• CPC Class Codes: H01L 21/7681 involving one or more buried masks

Abstract

The present invention generally provides a method for depositing a low dielectric constant film using an e-beam treatment. In one aspect, the method includes delivering a gas mixture comprising one or more organosilicon compounds and one or more hydrocarbon compounds having at least one cyclic group to a substrate surface at deposition conditions sufficient to deposit a non-cured film comprising the at least one cyclic group on the substrate surface. The method further includes substantially removing the at least one cyclic group from the non-cured film using an electron beam at curing conditions sufficient to provide a dielectric constant less than 2.5 and a hardness greater than 0.5 GPa.

Claims

1. A method for depositing a low dielectric constant film, comprising:

delivering a gas mixture comprising one or more organosilicon compounds and one or more hydrocarbon compounds having at least one cyclic group to a substrate surface at deposition conditions sufficient to deposit a non-cured film comprising the at least one cyclic group on the substrate surface and having a hardness less than about 0.3 GPa; and

substantially removing the at least one cyclic group from the non-cured film using an electron beam at curing conditions sufficient to provide a dielectric constant less than 2.5 and a hardness greater than 0.5 GPa.

2. The method of claim 1, wherein the one or more organosilicon compounds has an oxygen to silicon ratio of at least 1:

1.

3. The method of claim 1, wherein the one or more organosilicon compounds has an oxygen to silicon ratio of at least 2:

1.

4. The method of claim 1, wherein the one or more organosilicon compounds has an oxygen to silicon ratio of about 4:

1.

5. The method of claim 1, wherein the one or more organosilicon compounds is selected from the group consisting of 3,5-trisilano-2,4,6-trimethylene, 1,3,5,7-tetramethylcyclotetrasiloxane (TMCTS), octamethylcyclotetrasiloxane (OMCTS), 1,3,5,7,9-pentamethylcyclopentasiloxane, 1,3,5,7-tetrasilano-2,6-dioxy-4,8-dimethylene, hexamethylcyclotrisiloxane, diethoxymethylsilane (DEMS), dimethyl, dimethoxysilane (DMDMOS), dimethoxymethylvinylsilane (DMMVS), trimethylsilane (TMS), derivatives thereof, and mixtures thereof.

6. The method of claim 1, wherein the at least one cyclic group is a partially saturated ring of five or six carbon atoms.

7. The method of claim 1, wherein the at least one cyclic groups is an unsaturated ring of five or six carbon atoms.

8. The method of claim 1, wherein the at least one cyclic groups is a saturated ring of five or six carbon atoms.

9. The method of claim 1, wherein the at least one cyclic group comprises a structure selected from a group consisting of aromatics, aryls, phenyls, cyclohexanes, cyclohexadienes, cycloheptadienes, and combinations thereof.

10. The method of claim 1, wherein the one or more compounds having at least one cyclic group is selected from the group consisting of alpha-terpinene (ATP), vinylcyclohexane (VCH), norbornadiene, phenylacetate, and combinations thereof.

11. The method of claim 1, wherein the gas mixture further comprises an oxidizing gas.

12. The method of claim 11, wherein the oxidizing gas comprises oxygen, carbon dioxide, or 2,3-butanedione.

13. The method of claim 11, wherein the oxidizing gas comprises a mixture of two or more oxidants selected from a group consisting of ozone, oxygen, carbon dioxide, carbon monoxide, water and nitrous oxide.

14. The method of claim 1, wherein the deposition conditions comprise a power density ranging from about 0.03 W/cm² to about 3.2 W/cm².

15. The method of claim 1, wherein the deposition conditions comprise a substrate temperature of about 100°

C. to about 400°

C. and a pressure from about 4 Torr to about 10 Torr.

16. The method of claim 1, wherein the curing conditions comprise an electron beam dosage from about 200 to about 400 micro coulombs per cm².

17. The method of claim 14, wherein the curing conditions comprise a temperature greater than room temperature.

18. A method for depositing a low dielectric constant film, comprising:

delivering a gas mixture comprising one or more organosilicon compounds, one or more hydrocarbon compounds having at least one cyclic group, and two or more oxidizing gases to a substrate surface at deposition conditions sufficient to deposit a non-cured film comprising the at least one cyclic group on the substrate surface and having a hardness less than 0.3 GPa; and

substantially removing the at least one cyclic group from the non-cured film using an electron beam at curing conditions sufficient to provide a dielectric constant less than 2.2 and a hardness greater than 0.4 GPa.

19. The method of claim 18, wherein the one or more compounds having at least one cyclic group is selected from the group consisting of alpha-terpinene (ATP), vinylcyclohexane (VCH), norbornadiene, phenylacetate, and combinations thereof.

20. The method of claim 18, wherein the one or more organosilicon compounds is selected from the group consisting of 3,5-trisilano-2,4,6-trimethylene, 1,3,5,7-tetramethylcyclotetrasiloxane (TMCTS), octamethylcyclotetrasiloxane (OMCTS), 1,3,5,7,9-pentamethylcyclopentasiloxane, 1,3,5,7-tetrasilano-2,6-dioxy-4,8-dimethylene, hexamethylcyclotrisiloxane, diethoxymethylsilane (DEMS), dimethyl, dimethoxysilane (DMDMOS), dimethoxymethylvinylsilane (DMMVS), trimethylsilane (TMS), derivatives thereof, and mixtures thereof.

21. The method of claim 18, wherein the one or more the oxidizing gas comprises oxygen, carbon dioxide, or 2,3-butanedione, ozone, carbon monoxide, water and nitrous oxide.

22. A method for depositing a low dielectric constant film, comprising:

delivering a gas mixture comprising two or more organosilicon compounds, one or more hydrocarbon compounds having at least one cyclic group, and one or more oxidizing gases to a substrate surface at deposition conditions sufficient to deposit a non-cured film comprising the at least one cyclic group on the substrate surface; and

substantially removing the at least one cyclic group from the non-cured film using an electron beam at curing conditions sufficient to provide a dielectric constant less than 2.5 and a hardness greater than 0.5 GPa, wherein the electron beam has a dosage greater than about 200 micro coulombs per cm².

23. The method of claim 22, wherein the one or more compounds having at least one cyclic group is selected from the group consisting of alpha-terpinene (ATP), vinylcyclohexane (VCH), norbornadiene, phenylacetate, and combinations thereof.

24. The method of claim 22, wherein the two or more organosilicon compounds is selected from the group consisting of 3,5-trisilano-2,4,6-trimethylene, 1,3,5,7-tetramethylcyclotetrasiloxane (TMCTS), octamethylcyclotetrasiloxane (OMCTS), 1,3,5,7,9-pentamethylcyclopentasiloxane, 1,3,5,7-tetrasilano-2,6-d ioxy-4,8-dimethylene, hexamethylcyclotrisiloxane, diethoxymethylsilane (DEMS), dimethyl, dimethoxysilane (DMDMOS), dimethoxymethylvinylsilane (DMMVS), trimethylsilane (TMS), derivatives thereof, and mixtures thereof.

25. The method of claim 22, wherein the one or more the oxidizing gas comprises oxygen, carbon dioxide, or 2,3-butanedione, ozone, carbon monoxide, water and nitrous oxide.

26. The method of claim 22, wherein the two or more organosilicon compounds comprises a mixture of at least one linear organosilicon compound and at least one cyclic organosilicon compound.