Tantalum amido-complexes with chelate ligands useful for CVD and ALD of TaN and Ta205 thin films
View Patent ↗Tantalum compounds of Formula I hereof are disclosed, having utility as precursors for forming tantalum-containing films such as barrier layers. The tantalum compounds of Formula I may be deposited by CVD or ALD for forming semiconductor device structures including a dielectric layer, a barrier layer on the dielectric layer, and a copper metallization on the barrier layer, wherein the barrier layer includes a Ta-containing layer and sufficient carbon so that the Ta-containing layer is amorphous. According to one embodiment, the semiconductor device structure is fabricated by depositing the Ta-containing barrier layer, via CVD or ALD, from a precursor including the tantalum compound of Formula I hereof at a temperature below about 400° C. in a reducing or inert atmosphere, e.g., a gas or plasma optionally containing a reducing agent.
1. A tantalum compound of Formula I comprising:
wherein: R 1 , R 2 , R 3 and R 4 can be the same as or different from one another, and each is independently selected from the group consisting of hydrocarbyl, alkyl, silyl, and alkylamino, with the provisos that R 1 ═R 2 ≠iso-propyl, and R 1 ═R 2 ≠cyclohexyl; and wherein said R 1 , R 2 , R 3 and R 4 may be optionally further substituted with a N, S, O, a halogen atom or a combination or sub-combination thereof.
2. The tantalum compound of claim 1 , having one or more compatible characteristics selected from the group consisting of:
(i) said alkylamino being Me 2 N— or MeHN— and said hydrazyl being Me 2 NNH—;
(ii) said alkyl being a C 1 alkyl, C 2 alkyl, C 3 alkyl, C 4 alkyl, C 5 alkyl, C 6 alkyl, C 7 alkyl, C 8 alkyl, C 9 alkyl, C 10 alkyl, C 11 alkyl or C 12 alkyl;
(iii) said alkyl being methyl, ethyl, n-propyl, i-propyl, n-butyl, or t-butyl;
(iv) R 1 and R 2 being the same and R 3 and R 4 being the same but R 1 and R 2 not being the same as R 3 and R 4 ;
(v) R 1 and R 2 not being the same but R 3 and R 4 being the same;
(vi) R 1 and R 2 being the same but R 3 and R 4 not being the same;
(vii) R 1 , R 2 , R 3 and R 4 not being the same;
(viii) R 1 ═R 2 ═R 3 ═R 4 ≠iso-propyl;
(ix) R 1 ═R 2 ═R 3 ═R 4 ≠cyclohexyl;
(x) none of R 1 , R 2 , R 3 and R 4 being the same; and
(xi) some of R 1 , R 2 , R 3 and R 4 being the same.
3. The tantalum compound of claim 1 provided in a solvent medium.
4. The tantalum compound of claim 3 , wherein said solvent is pentane, hexane, heptane, octane, decane, cyclohexane, THF, toluene, or DME.
5. A method of forming a tantalum-containing material on a substrate, said method including use of a tantalum compound of Formula (I)
wherein: R 1 , R 2 , R 3 and R 4 can be the same as or different from one another, and each is independently selected from the group consisting of hydrocarbyl, alkyl, silyl, and alkylamino; and wherein said R 1 , R 2 , R 3 and R 4 may be optionally further substituted with a N, S, O, a halogen atom or a combination or sub-combination thereof,
in a process selected from the group consisting of:
(1) a process comprising:
(a) volatilizing said tantalum compound of Formula I to form a precursor vapor, and
(b) contacting said precursor vapor with said substrate; and
(2) a process comprising:
(a) forming a tantalum-containing barrier layer from said tantalum compound of Formula I between a dielectric layer and a copper metallization layer on said substrate.
6. The method of claim 5 , wherein said contacting step (1)(b) is conducted in the presence of a co-reactant.
7. The method of claim 6 , wherein said co-reactant is ammonia.
8. The method of claim 5 , wherein said contacting step (1)(b) is conducted under chemical vapor deposition conditions.
9. The method of claim 5 , wherein said contacting step (1)(b) comprises chemical vapor deposition or atomic layer deposition.
10. The method of claim 5 , comprising the process (2), wherein a Cu or Ru seed layer is directly in contact with said copper metallization layer.
11. The method of claim 5 , comprising the process (2), wherein said forming step (a) comprises depositing said tantalum compound by chemical vapor deposition (CVD) at a temperature below about 400° C. in a reducing or inert atmosphere.
12. The method of claim 5 , comprising the process (2), wherein said forming step (a) comprises depositing said tantalum compound by atomic layer deposition (ALD) at a temperature below about 400° C. in a reducing or inert atmosphere.
13. A semiconductor device structure, including a dielectric layer, a barrier layer on the dielectric layer, and copper metallization on the barrier layer, wherein the barrier layer includes a Ta-containing amorphous layer made from a Ta compound of Formula I.
wherein: R 1 , R 2 , R 3 and R 4 can be the same as or different from one another, and each is independently selected from the group consisting of hydrocarbyl, alkyl, silyl, and alkylamino; and wherein said R 1 , R 2 , R 3 and R 4 may be optionally further substituted with a N, S, O, a halogen atom or a combination or sub-combination thereof,
and carbon.
14. The semiconductor device structure of claim 13 , characterized by at least one compatible characteristic selected from the group consisting of:
(i) said dielectric layer comprising a low k dielectric material;
(ii) said Ta-containing layer having a thickness in a range from about 10 Angstroms to about 1000 Angstroms;
(iii) said copper metallization including a copper seed layer or a ruthenium seed layer and a bulk copper metallization layer;
(iv) said copper metallization including a copper seed layer; and
(v) said copper metallization includes a ruthenium seed layer.
15. The tantalum compound of claim 1 , in a vapor form.
16. A method of forming a tantalum-containing material on a substrate, said method including use of a tantalum compound of Formula (I)
wherein: R 1 , R 2 , R 3 and R 4 can be the same as or different from one another, and each is independently selected from the group consisting of hydrogen, alkenyl, aryl and hydrazyl; and wherein said R 1 , R 2 , R 3 and R 4 may be optionally further substituted with a N, S, O, a halogen atom or a combination or sub-combination thereof,
in a process selected from the group consisting of:
(1) a process comprising:
(a) volatilizing said tantalum compound of Formula I to form a precursor vapor, and
(b) contacting said precursor vapor with said substrate; and
(2) a process comprising:
(a) forming a tantalum-containing barrier layer from said tantalum compound of Formula I between a dielectric layer and a copper metallization layer on said substrate.
17. The tantalum compound of claim 16 , wherein R 1 , R 2 , R 3 and R 4 are hydrogen.
18. The tantalum compound of claim 1 , wherein R 1 , R 2 , R 3 and R 4 are methyl.
19. The tantalum compound of claim 1 , comprising (Bu t NC(NMe 2 )NEt)Ta(NMe 2 ) 4 .
20. The method of claim 5 , comprising the process (1).