Patent ID: 6960675

Claim:
A precursor composition comprising at least one tantalum species selected from the group consisting of: (i) tethered amine tantalum complexes of the formula (I): wherein; each of R 1 , R 2 , R 3 and R 5 is independently selected from the group consisting of H, C 1 -C 4 alkyl, silyl, C 3 -C 8 cycloalkyl, C 1 -C 4 alkylsilyl, C 6 -C 10 aryl and nitrogen-containing groups such as NR 6 R 7 , wherein R 6 and R 7 are the same as or different from one another and each is independently selected from the group consisting of H, C 1 -C 4 alkyl, and C 3 -C 8 cycloalkyl, or alternatively NR 1 R 2 may be represented by the molecular moiety wherein m=1, 2, 3, 4, 5 or 6; R 4 is selected from the group consisting of C 1 -C 4 alkylene, silylene (—SiH 2 —), C 1 -C 4 dialkylsilylene and NR 8 , wherein R 8 is selected from the group consisting of H, C 3 -C 8 cycloalkyl and C 1 -C 4 alkyl; and n is 1, 2, 3, or 4, but where R 4 is silylene, C 1 -C 4 dialkylsilylene or NR 8 , n must be 1; (ii) tethered amine tantalum complexes of the formula (II): wherein: each of R 1 , R 2 , R 3 and R 5 is independently selected from the group consisting of H, C 1 -C 4 alkyl, silyl, C 3 -C 8 cycloalkyl, C 1 -C 4 alkylsilyl, C 6 -C 10 aryl and nitrogen-containing groups such as NR 6 R 7 , wherein R 6 and R 7 are the same as or different from one another and each is independently selected from the group consisting of H, C 1 -C 4 alkyl, and C 3 -C 8 cycloalkyl, or alternatively NR 1 R 2 may be represented by the molecular moiety wherein m=1, 2, 3, 4, 5 or 6; R 4 as selected from the group consisting of C 1 -C 4 alkylene, silylene (—SiH 2 —), C 1 -C 4 dialkylsilylene and NR 8 , wherein R 8 is selected from the group consisting of H, C 3 -C 8 cycloalkyl and C 1 -C 4 alkyl; and n is 1, 2, 3, or 4, but where R 4 is silylene, C 1 -C 4 dialkylsilylene or NR 8 , n must be 1; and (iii) tantalum amide compounds of the formula (III): (R 1 R 2 N) 5-n Ta(NR 3 R 4 ) n (III) wherein: at least one of NR 1 R 2 and NR 3 R 4 may be represented by the molecular moiety wherein m=1, 2, 3, 4, 5 or 6, and wherein when only one of NR 1 R 2 and NR 3 R 4 is said molecular moiety the other of NR 1 R 2 and NR 3 R 4 has substituents R 1 and R 2 in the case of NR 1 R 2 and R 3 and R 4 in the case of NR 3 R 4 which are the same as or different from one another and each is independently selected from the group consisting of C 1 -C 4 alkyl, silyl, C 3 -C 8 cycloalkyl, C 1 -C 4 alkylsilyl, and C 6-C 10 aryl, and n is 1, 2, 3, or 4.