Chemical vapor deposition precursors for deposition of tantalum-based materials
Tantalum precursors suitable for chemical vapor deposition of tantalum-containing material, e.g., tantalum, TaN, TaSiN, etc., on substrates. The tantalum precursors are substituted cyclopentadienyl tantalum compounds. In one aspect of the invention, such compounds are silylated to constitute tantalum/silicon source reagents. The precursors of the invention are advantageously employed in semiconductor manufacturing applications to form diffusion barriers in connection with copper metallization of the semiconductor device structure.
1. A tantalum precursor vapor, comprising vapor of a compound of the formula:
wherein:
n is an integer having a value of from 1 to 5;
each R can be the same or different and each is independently selected from the group consisting of D, H, CH 3 , C 2 H 5 , i-C 3 H 7 , C 4 H 9 and Si(R″) 3 wherein each R″ is independently selected from H and C 1 -C 4 alkyl; and
each of R′ can be the same or different and each is independently selected from the group consisting of D, H, C 1 -C 4 alkyl, and Si(R″) 3 wherein each R″ is independently selected from H and C 1 -C 4 alkyl;
with the provisos that (i) each of the R groups and R′ are not simultaneously all H, and (ii) when each of R′ is H, and n is 1, both R groups are not simultaneously trimethylsilyl.
2. The compound of claim 1 , wherein at least one of R, R′ is Si(R″) 3 wherein each R″ is independently selected from H and C 1 -C 4 alkyl.
3. The compound of claim 1 , wherein at least one of R, R′ is trimethylsilyl.
4. The compound of claim 1 , wherein n is 1 for each cyclopentadienyl ring.
5. The compound of claim 4 , wherein R on each cyclopentadienyl ring is trimethylsilyl.
6. The compound of claim 1 , wherein each of the R groups and R′ are independently selected from H, methyl, isopropyl, t-butyl, trimethylsilyl, and t-butylsilyl.
7. The compound of claim 6 , wherein at least one of the R groups and R′ is trimethylsilyl.
8. The compound of claim 7 , wherein n is 1 for each cyclopentadienyl ring.
9. The compound of claim 8 , wherein R on each cyclopentadienyl ring is trimethylsilyl.
10. The compound of claim 1 , wherein each of the R groups and R′ are independently selected from H and Si(R″) 3 wherein each R″ is independently selected from H and C 1 -C 4 alkyl.
11. The compound of claim 10 , wherein n is 1 for each cyclopentadienyl ring.
12. The compound of claim 11 , wherein R on each cyclopentadienyl ring is trimethylsilyl.
13. The compound of claim 11 , wherein each R is H.
14. The compound of claim 13 , wherein at least one of R′ is Si(R″) 3 wherein each R″ is independently selected from H and C 1 -C 4 alkyl.
15. The compound of claim 14 , wherein one of R′ is Si(R″) 3 wherein each R″ is independently selected from H and C 1 -C 4 alkyl.
16. A tantalum precursor vapor, comprising vapor of a compound selected from among compounds of the formula:
wherein TMS is trimethylsilyl and R′ is selected from the group consisting of D, C 1 -C 4 alkyl, and Si(R″) 3 wherein each R″ is independently selected from H and C 1 -C 4 alkyl.
17. A method of synthesizing a cyclopentadienyl tantalum compound, comprising conducting the following reaction:
[(R) n Cp] 2 TaH 3 +R′Li→(RCp) 2 TaH 2 R′+½H 2
wherein:
each R can be the same or different and each is independently selected from the group consisting of D, H, CH 3 , C 2 H 5 , i-C 3 H 7 , C 4 H 9 and Si(R″) 3 wherein each R″ is independently selected from H and C 1 -C 4 alkyl; and
each of R′ can be the same or different and each is independently selected from the group consisting of D, H, C 1 -C 4 alkyl, and Si(R″) 3 wherein each R″ is independently selected from H and C 1 -C 4 alkyl.
18. A method of synthesizing a cyclopentadienyl tantalum compound, comprising conducting the following reaction:
(RCp) 2 TaH 3 +RSiH 3 →(RCp) 2 TaH 2 (RSiH 2 )+H 2
wherein:
each R can be the same or different and each is independently selected from the group consisting of D, H, CH 3 , C 2 H 5 , i-C 3 H 7 , C 4 H 9 and Si(R″) 3 wherein each R″ is independently selected from H and C 1 -C 4 alkyl.
19. A method of synthesizing a cyclopentadienyl tantalum compound, comprising conducting the following reaction:
(RCp) 2 TaH 3 +2R″SiH 3 →(RCp) 2 TaH(R″SiH 2 ) 2 +H 2
wherein:
each R can be the same or different and each is independently selected from the group consisting of D, H, CH 3 , C 2 H 5 , i-C 3 H 7 , C 4 H 9 and Si(R″) 3 wherein each R″ is independently selected from H and C 1 -C 4 alkyl.