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

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—Cn—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 —SiH2— moieties, either as terminal groups (—SiH2R) or embedded in a carbosilane cyclic compound, wherein R is H, a C1 to C6 linear or branched alkyl-group, a C3-C6 cyclic alkyl-group, a C1 to C6 linear or branched alkenyl-group, a C3-C6 cyclic alkenyl-group, or a combination thereof, and
• wherein the reaction mixture further comprises a polysilane that contains more than two —SiH2R function groups, wherein R is H, a C1 to C6 linear or branched alkyl-group, a C3-C6 cyclic alkyl-group, a C1 to C6 linear or branched alkenyl-group, a C3-C6 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:
• R1aSi[—(CH2)b—SiH2R2]c (I)
• wherein R1, R2 are independently H a C1 to C6 linear or branched alkyl-group, a C3-C6 cyclic alkyl-group, a C1 to C6 linear or branched alkenyl-group, a C3-C6 cyclic alkenyl-group, or combination thereof;
• a=0 to 2;
• b=1 to 4;
• c=4-a;
• or
• R3eC[—(CH2)f—SiH2R4]g (II)
• wherein R3, R4 are independently H, a C1 to C6 linear or branched alkyl-group, a C3-C6 cyclic alkyl-group, a C1 to C6 linear or branched alkenyl-group, a C3-C6 cyclic alkenyl-group, or combination thereof;
• e=0 to 2;
• f=0 to 3;
• g=4-e;
• or
• wherein R5 is H, a C1 to C6 linear or branched alkyl-group, a C3-C6 cyclic alkyl-group, a C1 to C6 linear or branched alkenyl-group, a C3-C6 cyclic alkenyl-group, or combination thereof;
• m=0 to 4;
• n=2 to 4;
• and the scaffold is a hydrocarbon scaffold;
• or
• R6x-1,3,5-trisilacyclohexane (IV)
• wherein R6 is a C1 to C6 linear or branched alkyl-group, a C3-C6 cyclic alkyl-group, a C1 to C6 linear or branched alkenyl-group, a C3-C6 cyclic alkenyl-group;
• x=0 to 3.