Nitrogen-free dielectric anti-reflective coating and hardmask

• US 20040214446A1
• Filed: 12/10/2003
• Published: 10/28/2004
• Est. Priority Date: 07/11/2002
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Zhu, Lei, Rathi, Sudha, Bencher, Christopher D., Kim, Bok Hoen, Silvetti, Mario D., Ahn, Sang H., Wang, Yuxiang May, Fung, Miguel, Jung, Keebum, MʼSaad, Hichem
• Granted Patent: US 6,927,178 B2
• Time in Patent Office: Days
• US Class Current: 438/706
• 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 21/022 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 21/02216 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 21/0276 using an anti-reflective coating anti-reflective coating for lithography in general G03F7/09
• CPC Class Codes: H01L 21/31144 using masks
• CPC Class Codes: H01L 21/314 Inorganic layers H01L21/3105, H01L21/32 take precedence
• CPC Class Codes: H01L 21/31633 Deposition of carbon doped silicon oxide, e.g. SiOC
• CPC Class Codes: H01L 21/7681 involving one or more buried masks
• 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: Y10S 438/952 Utilizing antireflective layer

Abstract

Methods are provided for depositing a dielectric material. The dielectric material may be used for an anti-reflective coating or as a hardmask. In one aspect, a method is provided for processing a substrate including introducing a processing gas comprising a silane-based compound and an oxygen and carbon containing compound to the processing chamber and reacting the processing gas to deposit a nitrogen-free dielectric material on the substrate. The dielectric material comprises silicon and oxygen. In another aspect, the dielectric material forms one or both layers in a dual layer anti-reflective coating.

Claims

1. A method for processing a substrate, comprising:

depositing a first anti-reflective layer; and

depositing a second anti-reflective layer on the first anti-reflective layer by a process comprising;

introducing a processing gas comprising a compound comprising an oxygen-free silane-based compound and an oxygen and carbon containing compound to the processing chamber; and

reacting the processing gas to deposit a nitrogen-free dielectric material on the substrate, wherein the nitrogen-free dielectric material comprises at least silicon and oxygen.

2. The method of claim 1, wherein the oxygen-free silane-based compound comprises one or more compounds having the formula Si_xH_2x+2, Si_xH_yCl_z, (R)_zSi_xH_y, or combinations thereof, wherein X is 1 to 4, Y is 0 to 2X+1, Z is 2X+2, and R is an organic group.

3. The method of claim 1, wherein the oxygen and carbon containing compound is an organosilicon selected from the group of tetraethoxysilane (TEOS), triethoxyfluorosilane (TEFS), 1,3,5,7-tetramethylcyclotetrasiloxane (TMCTS), dimethyldiethoxysilane, and combinations thereof.

4. The method of claim 3, wherein the ratio of the oxygen-free silane-based compound to the oxygen-containing organosilicon compound is between about 1 sccm:

20 mgm and about 6 sccm;

5 mgm.

5. The method of claim 1, wherein the second anti-reflective layer comprises silicon, oxygen, and carbon, and has an oxygen content between about 15 atomic percentage and about 50 atomic percentage of oxygen.

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

7. The method of claim 1, wherein the reacting the processing gas comprises generating a plasma at a RF power level between about 50 watts and about 10,000 watts at a pressure between about 1 Torr and about 50 Torr and a substrate temperature between about 100°

C. and about 1000°

C.

8. The method of claim 1, wherein the first anti-reflective layer is depositing by introducing a second processing gas comprising a compound comprising an oxygen-free silane-based compound and an oxygen and carbon containing compound to the processing chamber and reacting the second processing gas to deposit a nitrogen-free dielectric material on the substrate comprising at least silicon and oxygen.

9. The method of claim 1, further comprising an oxide capping layer disposed on the second anti-reflective coating.

10. The method of claim 1, further comprising exposing the second anti-reflective coating to a nitrogen-free oxidizing plasma.

11. The method of claim 1, wherein the first anti-reflective coating and the second anti-reflective coating have a combined reflectivity below 1 percentage.

12. The method of claim 1, further comprising:

depositing a photoresist material on the anti-reflective coating; and

patterning the photoresist layer.

13. The method of claim 12, further comprising:

etching the second anti-reflective coating and any underlying dielectric material to define an interconnect opening therethrough; and

depositing one or more conductive materials to fill the interconnect opening.

14. The method of claim 1, wherein the oxygen and carbon containing compound is carbon dioxide.

15. The method of claim 1, wherein the first antireflective coating has an extinction coefficient that is higher than the extinction coefficient for the second antireflective coating.

16. The method of claim 1, wherein the processing gas further comprises an inert gas selected from the group of argon, helium, neon, xenon, or krypton, and combinations thereof.

17. The method of claim 1, wherein the deposited nitrogen-free dielectric material has an index of refraction between about 1.5 and about 2.2.

18. The method of claim 1, wherein the deposited nitrogen-free dielectric material has an extinction coefficient of between about 0 and about 2.

19. The method of claim 7, wherein the reacting the processing gas comprises generating a plasma at a RF power level between about 50 watts and about 10,000 watts at a pressure between about 1 Torr and about 50 Torr and a substrate temperature between about 100°

C. and about 1000°

C.

20. The method of claim 1, wherein the first anti-reflective coating and the second anti-reflective coating have an etch selectivity of oxide to anti-reflective coating of about 4:

1 or greater.