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US-12624248-B2 - Curable formulations for forming low-k dielectric silicon-containing films using polycarbosilazane

US12624248B2US 12624248 B2US12624248 B2US 12624248B2US-12624248-B2

Abstract

A method of forming a gap filling on a substrate, the substrate having gaps formed therein, comprises: producing a gap filling polycarbosilazane polymer or oligomer by a polymerization of a reaction mixture of carbosilanes with amines; forming a solution containing the gap filling polycarbosilazane polymer or oligomer; and contacting the solution with the substrate via a spin-on coating, spray coating, dip coating, or slit coating technique to fill the gaps in the substrate forming the silicon and carbon containing gap filling, wherein a concentration of the gap filling polycarbosilazane polymer or oligomer in the solution ranges from 1 to 60 wt %.

Inventors

  • Yumin Liu
  • Jean-Marc Girard
  • Peng Zhang
  • Fan QIN
  • Gennadiy ITOV
  • Fabrizio MARCHEGIANI
  • Thomas J. LARRABEE
  • Venkateswara R. Pallem

Assignees

  • L'Air Liquide, Société Anonyme pour l'Etude et l'Exploitation des Procédés Georges Claude
  • AMERICAN AIR LIQUIDE, INC.

Dates

Publication Date
20260512
Application Date
20221031

Claims (19)

  1. 1 . A method of forming a silicon and carbon containing gap filling on a substrate, the substrate having gaps formed therein, the method comprising the steps of: producing a gap filling polycarbosilazane polymer or oligomer by a polymerization of a reaction mixture of carbosilanes with amines; forming a solution containing the gap filling polycarbosilazane polymer or oligomer; and contacting the solution with the substrate via a spin-on coating, spray coating, dip coating, or slit coating technique to fill the gaps in the substrate forming the silicon and carbon containing gap filling, wherein the carbosilanes contain at least two —SiH 2 — moieties, either as terminal groups (—SiH 2 R) or embedded in a carbosilane cyclic compound, wherein R is H, a C 1 to C 6 linear or branched alkyl-group, a C 3 -C 6 cyclic alkyl-group, a C 1 to C 6 linear or branched alkenyl-group, a C 3 -C 6 cyclic alkenyl-group, or a combination thereof, wherein a concentration of the gap filling polycarbosilazane polymer or oligomer in the solution ranges from 1 to 60 wt %, wherein the carbosilane has the formula: R 1 a Si[—(CH 2 ) b —SiH 2 R 2 ] c (I) wherein R 1 , R 2 are independently H a C 1 to C 6 linear or branched alkyl-group, a C 3 -C 6 cyclic alkyl-group, a C 1 to C 6 linear or branched alkenyl-group, a C 3 -C 6 cyclic alkenyl-group, or combination thereof; a=0 to 2; b=1 to 4; c=4-a; or R 3 e C[—(CH 2 ) f —SiH 2 R 4 ] g (II) wherein R 3 , R 4 are independently H, a C 1 to C 6 linear or branched alkyl-group, a C 3 -C 6 cyclic alkyl-group, a C 1 to C 6 linear or branched alkenyl-group, a C 3 -C 6 cyclic alkenyl-group, or combination thereof; e=0 to 2; f=0 to 3; g=4-e; or wherein R 5 is H, a C 1 to C 6 linear or branched alkyl-group, a C 3 -C 6 cyclic alkyl-group, a C 1 to C 6 linear or branched alkenyl-group, a C 3 -C 6 cyclic alkenyl-group, or combination thereof; m=0 to 4; n=2 to 4; and the scaffold is a hydrocarbon scaffold; or R 6 x -1,3,5-trisilacyclohexane (IV) wherein R 6 is a C 1 to C 6 linear or branched alkyl-group, a C 3 -C 6 cyclic alkyl-group, a C 1 to C 6 linear or branched alkenyl-group, a C 3 -C 6 cyclic alkenyl-group; x=0 to 3.
  2. 2 . The method of claim 1 , wherein a concentration of the gap filling polycarbosilazane polymer or oligomer in the solution ranges from 1 to 40 wt %.
  3. 3 . The method of claim 1 , wherein the gap is a trench, a pillar or a nanowire in the substrate.
  4. 4 . The method of claim 1 , wherein a width of the gap ranges from larger than 5 nm and less than approximately 10 μm.
  5. 5 . The method of claim 1 , wherein an aspect ratio of the gap ranges from approximately 2:1 to approximately 100:1.
  6. 6 . The method of claim 1 , wherein an aspect ratio of the gap ranges from approximately 1:1 to approximately 1:10.
  7. 7 . The method of claim 1 , further comprising the step of repeating the step of the contacting the solution with the substrate via the spin-on coating, spray coating, dip coating, or slit coating technique to fill the gaps in the substrate forming the silicon and carbon containing gap filling until a desired substrate forming the silicon and carbon containing gap filling is obtained.
  8. 8 . The method of claim 1 , further comprising the step of pre-baking the silicon and carbon containing gap filling under N 2 or Air atmosphere at a temperature ranging from approximately 50° C. to 400° C. to remove solvents; and subsequently hard baking the silicon and carbon containing gap filling by a heat-induced radical reaction or a UV-Vis photo induced radical reaction in an atmosphere of O 2 , O 3 , H 2 O, H 2 O 2 , N 2 O, or NO, air, compressed air, or combinations thereof at a temperature range of 200-1000° C. to convert the silicon and carbon containing gap filling to a SiOC or SiOCN containing gap filling.
  9. 9 . The method of claim 1 , wherein the gap filling polycarbosilazane polymer or oligomer has a backbone that comprises Si—N units, Si—N—C n —N—Si units, Si—N—Si units or combinations thereof, wherein n≥1, wherein the backbone includes cross-linked Si—N units, Si—N—C n —N—Si units or Si—N—Si units, branched Si-N units, Si—N—C n —N—Si units or Si—N—Si units, or combinations thereof.
  10. 10 . The method of claim 1 , wherein the carbosilane is selected from the group consisting of Si[—(CH 2 )—SiH 3 ] 4 , Si[—(CH 2 ) 2 —SiH 3 ] 4 , Si[—(CH 2 ) 3 —SiH 3 ] 4 , Si[—(CH 2 ) 4 —SiH 3 ] 4 , R 1 Si[—(CH 2 )—SiH 3 ] 3 , R 1 Si[—(CH 2 ) 2 —SiH 3 ] 3 , R 1 Si[—(CH 2 ) 3 —SiH 3 ] 3 , R 1 Si[—(CH 2 ) 4 —SiH 3 ] 3 , H 3 Si—CH 2 —SiH 2 —CH 2 —SiH 3 (bis(silylmethyl)silane), H 3 Si—(CH 2 ) 2 —SiH 2 —(CH 2 ) 2 —SiH 3 (bis(2-silylethyl)silane), H 3 Si—(CH 2 ) 3 —SiH 2 —(CH 2 ) 3 —SiH 3 (bis(3-silylpropyl)silane), and H 3 Si—(CH 2 ) 4 —SiH 2 —(CH 2 ) 4 —SiH 3 (bis(4-silylbutyl)silane), C[—SiH 3 ] 4 (tetrasilylmethane), C[—(CH 2 )—SiH 3 ] 4 (2,2-bis(silylmethyl)propane-1,3-diyl)bis(silane)), C[—(CH 2 ) 2 —SiH 3 ] 4 (3,3-bis(2-silylethyl)pentane-1,5-diyl)bis(silane)), and C[—(CH 2 ) 3 —SiH 3 ] 4 (4,4-bis(3-silylpropyl) heptane-1,7-diyl)bis(silane)), R 1 C[—SiH 3 ] 3 , R 1 C[—(CH 2 )—SiH 3 ] 3 , R 1 C[—(CH 2 ) 2 —SiH 3 ] 3 , and R 1 C[—(CH 2 ) 3 —SiH 3 ] 3 , H 3 Si—CH 2 —SiH 3 (bisilylmethane), H 3 Si—(CH 2 ) 5 —SiH 3 (1,5-disilylpentane), and H 3 Si—(CH 2 ) 7 —SiH 3 (1,7-disilylheptane), 1,3-disilylcyclopentane, 1,2-disilylcyclopentane, 1,4-disilylcyclohexane, 1,3-disilylcyclohexane, 1,2-disilylcyclohexane, 1,3,5-trisilylcyclohexane and 1,3,5-trisilylbenzene, 2-Me-TSCH, 2-Et-TSCH, 2-iPr-TSCH, 2-nPr-TSCH, 2-nBu-TSCH, 2-tBu-TSCH, 2-sBu-TSCH, 2-iBu-TSCH, 2,4-Me 2 -TSCH, 2,4-Et 2 -TSCH, 2,4-iPr 2 -TSCH, 2,4-nPr 2 -TSCH, 2,4-nBu 2 -TSCH, 2,4-iBu 2 -TSCH, 2,4-tBu 2 -TSCH, 2,4-sBu 2 -TSCH, 2,4,6-Me 3 -TSCH, 2,4,6-Et 3 -TSCH, 2,4,6-iPr 3 -TSCH, 2,4,6-nPr 3 -TSCH, 2,4,6-nBu 3 -TSCH, 2,4,6-iBu 3 -TSCH, 2,4,6-tBu 3 -TSCH, 2,4,6-sBu 3 -TSCH, and combinations thereof; and wherein R 1 is H, a C 1 -C 6 linear, branched, or cyclic alkyl-group, a C 1 -C 6 linear, branched, or cyclic alkenyl-group, or a combination thereof.
  11. 11 . The method of claim 1 , wherein the carbosilane is 1,3,5-trisilapentane (CAS No.: 5637-99-0) or 1,3,5-trisilacyclohexane (CAS No.: 291-27-0).
  12. 12 . The method of claim 1 , wherein the reaction mixture contains a polysilane selected from one or more of neopentasilane (or 2,2-disilyltrisilane) (Si(SiH 3 ) 4 ), n-tetrasilane (SiH 3 (SiH 2 ) 2 SiH 3 ), 2-silyl-tetrasilane ((SiH 3 ) 2 SiHSiH 2 SiH 3 ), trisilylamine (N(SiH 3 ) 3 ), alkylamino-substituted trisilylamines or oligomers of trisilylamines.
  13. 13 . The method of claim 1 , wherein the step of the producing the gap filling polycarbosilazane polymer or oligomer comprises the step of adding a catalyst to the reaction mixture, wherein the gap filling polycarbosilazane polymer or oligomer is produced by a polymerization of the reaction mixture through a catalytic dehydrocoupling (DHC) reaction.
  14. 14 . The method of claim 12 , wherein the catalyst is NH 4 Cl.
  15. 15 . The method of claim 12 , wherein the gap filling polycarbosilazane polymer or oligomer is produced by the polymerization of the carbosilanes with amines through the catalytic dehydrocoupling (DHC) reaction selected from one or more of i) two carbosilanes with two amines, wherein one of the two carbosilanes contains the at least two —SiH 2 — moieties, either as the terminal groups (—SiH 2 R) or embedded in the carbosilane cyclic compound; ii) two carbosilanes with two amines, wherein one of the two amines contains more than two N—H bonds; and iii) more than two carbosilanes with more than two amines, wherein R is H, a C 1 to C 6 linear or branched alkyl-group, a C 3 -C 6 cyclic alkyl-group, a C 1 to C 6 linear or branched alkenyl-group, a C 3 -C 6 cyclic alkenyl-group, or a combination thereof.
  16. 16 . A silicon and carbon containing gap filling solution for spin-on coating, spray coating, dip coating, or slit coating technique comprising: a gap filling polycarbosilazane polymer or oligomer that has a backbone comprising Si—N units, Si—N—C n —N—Si units, Si—N—Si units or combinations thereof, wherein n≥1, wherein the gap filling polycarbosilazane polymer or oligomer is obtained from a reaction mixture comprising carbosilanes and amines, wherein the carbosilanes contain at least two —SiH 2 — moieties, either as terminal groups (—SiH 2 R) or embedded in a carbosilane cyclic compound, wherein R is H, a C 1 to C 6 linear or branched alkyl-group, a C 3 -C 6 cyclic alkyl-group, a C 1 to C 6 linear or branched alkenyl-group, a C 3 -C 6 cyclic alkenyl-group, or a combination thereof, and wherein the reaction mixture further comprises a polysilane that contains more than two —SiH 2 R function groups, wherein R is H, a C 1 to C 6 linear or branched alkyl-group, a C 3 -C 6 cyclic alkyl-group, a C 1 to C 6 linear or branched alkenyl-group, a C 3 -C 6 cyclic alkenyl-group, or a combination thereof, wherein a concentration of the gap filling polycarbosilazane polymer or oligomer in the silicon and carbon containing gap filling solution ranges from 1 to 60 wt %, wherein the carbosilane has the formula: R 1 a Si[—(CH 2 ) b —SiH 2 R 2 ] c (I) wherein R 1 , R 2 are independently H a C 1 to C 6 linear or branched alkyl-group, a C 3 -C 6 cyclic alkyl-group, a C 1 to C 6 linear or branched alkenyl-group, a C 3 -C 6 cyclic alkenyl-group, or combination thereof; a=0 to 2; b=1 to 4; c=4-a; or R 3 e C[—(CH 2 ) f —SiH 2 R 4 ] g (II) wherein R 3 , R 4 are independently H, a C 1 to C 6 linear or branched alkyl-group, a C 3 -C 6 cyclic alkyl-group, a C 1 to C 6 linear or branched alkenyl-group, a C 3 -C 6 cyclic alkenyl-group, or combination thereof; e=0 to 2; f=0 to 3; g=4-e; or wherein R 5 is H, a C 1 to C 6 linear or branched alkyl-group, a C 3 -C 6 cyclic alkyl-group, a C 1 to C 6 linear or branched alkenyl-group, a C 3 -C 6 cyclic alkenyl-group, or combination thereof; m=0 to 4; n=2 to 4; and the scaffold is a hydrocarbon scaffold; or R 6 x -1,3,5-trisilacyclohexane (IV) wherein R 6 is a C 1 to C 6 linear or branched alkyl-group, a C 3 -C 6 cyclic alkyl-group, a C 1 to C 6 linear or branched alkenyl-group, a C 3 -C 6 cyclic alkenyl-group; x=0 to 3.
  17. 17 . The silicon and carbon containing gap filling solution of claim 16 , wherein a concentration of the gap filling polycarbosilazane polymer or oligomer in the silicon and carbon containing gap filling solution ranges from 1 to 40 wt %.
  18. 18 . The silicon and carbon containing gap filling solution of claim 16 , wherein a solvent is selected from at least one of hydrocarbons, aromatic solvents selected from toluene, xylene or mesitylene, ether solvents selected from tert-butyl ethers, THF or glymes, or amine solvents selected from trialkylamine or dialkylamine.
  19. 19 . The method of claim 16 , wherein the carbosilane is 1,3,5-trisilapentane (CAS No.: 5637-99-0) or 1,3,5-trisilacyclohexane (CAS No.: 291-27-0).

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation-in-part of U.S. application Ser. No. 16/731,728, filed on Dec. 31, 2019, the teachings of which are incorporated herein by reference. TECHNICAL FIELD The present invention relates to processes of deposition of a low-k dielectric silicon and carbon containing film on a substrate by wet coating, preferably spin-on deposition (SOD) using a silicon and carbon containing film-forming composition comprising a polycarbosilazane polymer or oligomer containing formulation, followed by a curing step and a hardbaking step. BACKGROUND Spin-on coating is a procedure used to deposit uniform thin films onto mainly flat substrates by centrifugal force. In general, a coating formulation is applied on the center of the substrate, which is then spun at a certain speed. The coating formulation is spread by centrifugal force and forms a film to cover the substrate. The thickness of the film is typically controlled by the concentration of the coating formulation and the spin rate. In order to make the coating material flowable, a volatile solvent is used. The volatile solvent may be evaporated off as the film is formed. The thickness of the film depends on the angular speed of spinning, the viscosity and concentration of the solution, and the solvent. Spin-on coating is widely used in micro-electronics fabrication to make a variety of films such as photo-resists, anti-reflective coatings, low-k dielectric films, silicon oxide films, etc. In some applications, the spin-on dielectrics formed by a spin-on coating process are able to insulate transistors or conductive layers. The increase in semiconductor design integration by feature size reduction has resulted in the back end of line manufacturing (BEOL) in increased levels of interconnected metal lines and vertical vias, insulated from each other by thin dielectric layers. Dielectric layers having a low dielectric constant (low-k) are sought for such thin dielectric layers as they limit electromagnetic cross talks between the metal lines. At the transistor manufacturing level (Front End of Line), several steps in device manufacturing require the usage of dielectric films having the capability to deposit into deep trenches and holes. For instance, shallow trench isolation and fin isolation require the deposition of dielectric films in the bottom of trenches. Similarly, to the BEOL application, there is also a growing need to fill such features with insulating films having a lower dielectric constant than SiO2. Compared to the BEOL low-k films, Front End of Line additional constraints are the requirements of a high gap filling capability, and for the deposited film to withstand the high temperatures that are required when building the rest of the chip, i.e. typically >400° C., and more preferably >500° C., without significant impact on the film physical and chemical properties (dimension, stress, dielectric constant, chemical bonding, etc.). The semiconductor industry has developed several low-k materials that are inorganic, organic or hybrid materials to replace silicon dioxide. These materials may be deposited by either chemical vapor deposition (CVD) or spin-on deposition (SOD) processes. Materials such as polyimide, carbon-doped silicon oxides and polyarylene may be deposited using SOD techniques. US 2019/0040279 to Khandelwal et al. discloses process and formulation for polycarbosilazane containing formulations comprising precursors having a unit having the formula: [—NR—R4R1Si—(CH2)—SiR2R3—]n, where n=2 to 400; R is H: R2, R3, R4, 5 are independently H, a hydrocarbon group, or an alkylamino group, and provided that at least one of R2, R3, R4 and R5 is H. US 2015/0087139 to O'Neil et al. discloses precursors and method for forming Si-containing films using organoaminosilane precursors, for example, H3Si(CH2)nSiH2NR—C(Me)=NR. WO 2016/160991 to Kerrigan et al. discloses Si-containing film-forming composition that comprise of Si—N containing precursors and methods for synthesizing these precursors by catalytic dehydrogenative coupling of carbosilanes with ammonia, amines, and amidine. U.S. Pat. No. 5,260,377 to Leibfried et al. discloses crosslinkable carbosilane polymer formulation prepared from saturated or unsaturated carbosilane polymers containing reactive silicon hydride radicals in the polymer chain combined with polycyclic polyene crosslinkers that have two or more double bonds reactive in a hydrosilylation crosslinking reaction. U.S. Pat. No. 9,243,324 to Bowen et al. discloses the methods for forming non-oxygen containing Si-based films that contain>50 atomic % of silicon. In one embodiment, the non-oxygen containing Si-based films were deposited using at least one organosilicon precursor having at least two —SiH3 groups with at least one C2-3 linkage between silicon atoms such as 1,4-disilabutane. US Patent Application 2019/0055645 to Li et al. discloses Si-containing film-forming composition th