Flowable film dielectric gap fill process

• US 7,888,233 B1
• Filed: 03/25/2009
• Issued: 02/15/2011
• Est. Priority Date: 03/25/2004
• Status: Active Grant

• Current Assignee: Novellus Systems Incorporated (LAM Research Corporation)
• Original Assignee: Novellus Systems Incorporated (LAM Research Corporation)
• Inventors: Huang, Judy H., Lang, Chi-I, Humayun, Raashina, Shanker, Sunil, Barnes, Michael, Gauri, Vishal
• Primary Examiner(s): Smoot; Stephen W
• Application Number:
  US12/411,243
• Time in Patent Office: 692 Days
• Field of Search: 438/428, 438/436, 257/E21.489
• US Class Current: 438/436
• 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: C23C 16/56 After-treatment
• CPC Class Codes: H01L 21/02164 the material being a silicon oxide, e.g. SiO2
• CPC Class Codes: H01L 21/02271 deposition by decomposition or reaction of gaseous or vapour phase compounds, i.e. chemical vapour deposition H01L21/02266 takes precedence
• CPC Class Codes: H01L 21/0234 treatment by exposure to a plasma
• CPC Class Codes: H01L 21/31 to form insulating layers thereon, e.g. for masking or by using photolithographic techniques encapsulating layers H01L21/56; After treatment of these layers; Selection of materials for these 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 21/31608 Deposition of SiO2 H01L21/31625, H01L21/31629 and H01L21/31633 take precedence
• CPC Class Codes: H01L 21/76224 using trench refilling with dielectric materials trench filling with polycristalline silicon H01L21/763; together with vertical isolation, e.g. trench refilling in a SOI substrate H01L21/76264

Abstract

Methods of this invention relate to filling gaps on substrates with a solid dielectric material by forming a flowable film in the gap. The flowable film provides consistent, void-free gap fill. The film is then converted to a solid dielectric material. In this manner gaps on the substrate are filled with a solid dielectric material. According to various embodiments, the methods involve reacting a dielectric precursor with an oxidant to form the dielectric material. In certain embodiments, the dielectric precursor condenses and subsequently reacts with the oxidant to form dielectric material. In certain embodiments, vapor phase reactants react to form a condensed flowable film.

Claims

1. A method of depositing a dielectric material on a substrate, the method comprising:

(a) introducing an oxidant reactant and a dielectric precursor reactant into a reaction chamber, such that the reactants are present in the chamber in vapor phase at the same time, wherein the oxidant reactant is steam; and

(b) reacting the oxidant reactant with the dielectric precursor reactant to form a flowable film.

2. The method of claim 1 further comprising (c) converting the flowable film to a solid dielectric material.

3. The method of claim 2 wherein reacting the dielectric precursor and the oxidant converts the flowable film to the solid dielectric material.

4. The method of claim 2 wherein the converting the flowable film comprises cross-linking the flowable film to produce the solid dielectric material.

5. The method of claim 2, wherein the converting the flowable film comprises removing hydrogen (—

H), hydroxyl (—

OH) or water (H₂O) groups to produce the solid dielectric material.

6. The method of claim 2, wherein the converting the flowable film occurs in the presence of the oxidant reactant introduced in (a).

7. The method of claim 2, wherein the steps (a) through (c) are repeated at least once to build up a film of a desired thickness.

8. The method of claim 1 wherein the dielectric precursor and the oxidant react in the vapor phase to form the flowable film.

9. The method of claim 1 wherein the substrate comprises gaps and forming the flowable film comprises selectively condensing the dielectric precursor in the gaps.

10. The method of claim 9 wherein forming the flowable film further comprises reacting the oxidant with the condensed dielectric precursor.

11. The method of claim 9 wherein the gaps have a dimension on the order of about 100 nanometers or less.

12. The method of claim 1, further comprising exposing the flowable film to a thermal anneal, ultraviolet (UV) radiation, microwave radiation, or a plasma anneal.

13. The method of claim 1, wherein the dielectric material is a silicon oxide.

14. The method of claim 1, wherein the precursor of the dielectric material is an alkoxysilane.

15. The method of claim 1, wherein the precursor of the dielectric material comprises one of more compounds selected from the list comprising triethoxysilane (TES), tetraethylorthosilane (TEOS), tetramethoxysilane (TMOS), methyl triethoxysilane (MTEOS), methyltrimethoxysilane (MTMOS), dimethyldimethoxysilane (DMDMOS), trimethylmethoxysilane (TMMOS), dimethyldiethoxysilane (DMDEOS), bis-triethoxysilylethane (BTEOSE) or bis-triethoxysilylmethane (BTEOSM), tetramethylcyclotetrasiloxane (TMCTS), octamethylcyclotetrasiloxane (OMCTS), and tetravinyltetramethylcyclotetrasiloxane (TVTMCTS).

16. The method of claim 1, further comprising exposing the flowable film to oxygen radicals.

17. The method of claim 1, further comprising introducing an alcohol into the reaction chamber.

18. The method of claim 1, wherein the dielectric precursor is mixed in a carrier solvent.

19. The method of claim 18, wherein the carrier solvent is an alcohol.

20. The method of claim 1, further comprising exposing the flowable film to a steam plasma.

21. A method of depositing a dielectric material on a substrate, the method comprising:

(a) introducing an oxidant reactant and a dielectric precursor reactant into a reaction chamber, such that the reactants are present in the chamber in vapor phase at the same time;

(b) reacting the oxidant reactant with the dielectric precursor reactant to form a flowable film; and

(c) exposing the flowable film to oxygen radicals.

22. The method of claim 21, wherein the oxidant reactant is selected from the group consisting of steam, ozone, oxygen, and a peroxide.

23. The method of claim 21, wherein the dielectric precursor reactant is an alkoxysilane.

24. The method of claim 21, wherein exposing the flowable film to oxygen radicals densifies the flowable film.

25. The method of claim 21, wherein the dielectric precursor and the oxidant react in the vapor phase to form the flowable film.

26. The method of claim 21, further comprising introducing an alcohol into the reaction chamber.

27. The method of claim 21, wherein the dielectric precursor is mixed in a carrier solvent.

28. The method of claim 27, wherein the carrier solvent is an alcohol.

29. The method of claim 21, further comprising exposing the flowable film to a steam plasma.

30. The method of claim 21, wherein the dielectric precursor comprises one of more compounds selected from the list comprising triethoxysilane (TES), tetraethylorthosilane (TEOS), tetramethoxysilane (TMOS), methyl triethoxysilane (MTEOS), methyltrimethoxysilane (MTMOS), dimethyldimethoxysilane (DMDMOS), trimethylmethoxysilane (TMMOS), dimethyldiethoxysilane (DMDEOS), bis-triethoxysilylethane (BTEOSE) or bis-triethoxysilylmethane (BTEOSM), tetramethylcyclotetrasiloxane (TMCTS), octamethylcyclotetrasiloxane (OMCTS), and tetravinyltetramethylcyclotetrasiloxane (TVTMCTS).