Synthesis and characterization of first row transition metal complexes containing α-imino alkoxides as precursors for deposition of metal films
A compound that is useful for forming a metal by reaction with a reducing agent is described by formula (I): wherein M is a metal selected from Groups 2 through 12 of the Periodic Table; and R 1 , R 2 , R 3 , and R 4 are each independently H or C 1 -C 8 alkyl.
1. A method for forming a metal-containing film, the method comprising contacting a compound having formula I with an activating agent to form the metal-containing film:
wherein
M is a metal selected from Groups 2 to 12 of the Periodic Table; and
R 1 , R 2 , R 3 , and R 4 are each independently H or C 1 -C 8 alkyl.
2. The method of claim 1 wherein the activating agent is a reducing agent.
3. The method of claim 2 wherein the reducing agent is selected from the group consisting of NH 2 NMe 2 , NH 2 NH 2 , AlEt 3 , AlMe 3 , HSiEt 3 , LiBHEt 3 , LiAlH 4 , BH 3 ·N(C 2 H 5 ) 3 , BH 3 ·NH(CH 3 ) 2 , pinacol borane, BH 3 ·S(CH 3 ) 2 , BH 3 ·THF, BH 3 ·2-picoline, decaborane, 9-Borabicyclo[3.3.1]nonane (9-BBN), BH 3 ·morpholine, and combinations thereof.
4. The method of claim 1 wherein the activating agent is an oxidizing agent or a nitriding agent.
5. The method of claim 1 wherein M is Cu, Cr, Mn, Fe, Co, or Ni.
6. The method of claim 1 wherein R 1 , R 2 , R 3 , and R 4 are each independently methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, or t-butyl.
7. The method of claim 6 wherein a substrate is contacted with a vapor of the compound having formula (I) to form a modified substrate surface during a first deposition cycle.
8. The method of claim 7 further comprising contacting the modified surface with a reducing agent to form a metal film disposed over the substrate during the first deposition cycle.
9. The method of claim 8 wherein the substrate is additionally contacted with the vapor of the compound having formula (I) and then the vapor of a reducing agent during a plurality of additional deposition cycles.
10. The method of claim 9 wherein the substrate is coated with from 1 to 5000 deposition cycles.
11. The method of claim 10 wherein the substrate is coated at a temperature from about 50 to 400° C.
12. The method of claim 11 wherein the substrate is contacted with a purge gas after contacting the substrate with the vapor of the compound having formula (I) and before contacting the substrate with the vapor of the reducing agent.
13. The method of claim 12 wherein the substrate is contacted with the purge gas after contacting the substrate with the vapor of the reducing agent and before a subsequent step of contacting the vapor of the compound.
14. The method of claim 1 wherein the compound having formula (I) is selected from the group consisting of bis(1-(tert-butylimino)-2,3,3-trimethylbutan-2-olate)nickel(II), bis(1-(tert-butylimino)-2,3,3-trimethylbutan-2-olate)cobalt(II), bis(1-(tert-butylimino)-2,3,3-trimethylbutan-2-olate)iron(II), bis(1-(tert-butylimino)-2,3,3-trimethylbutan-2-olate)manganese(II), bis(1-(tert-butylimino)-2,3,3-trimethylbutan-2-olate)chromium(II)(5), bis(1-(tert-butylimino)-2,3,3-trimethylbutan-2-olate)copper(II), bis(1-(tert-butylimino)-2,3-dimethylbutan-2-olate)nickel(II), bis(1-(tert-butylimino)-2,3-dimethylbutan-2-olate)cobalt(II), bis(1-(tert-butylimino)-2,3-dimethylbutan-2-olate)iron(II), bis(1-(tert-butylimino)-2,3-dimethylbutan-2-olate)copper(II), bis(3-((tert-butylimino)methyl)-2,2,4,4-tetramethylpentan-3-olate)manganese(II), bis(3-((tert-butylimino)methyl)-2,2,4,4-tetramethylpentan-3-olate)copper(II), bis(3-(isopropylimino)-2-methylbutan-2-olate)nickel(II), bis(3-(isopropylimino)-2-methylbutan-2-olate)cobalt(II), bis(3-(isopropylimino)-2-methylbutan-2-olate)iron(II), bis(3-(isopropylimino)-2-methylbutan-2-olate)manganese(II), bis(3-(isopropylimino)-2-methylbutan-2-olate)chromium(II) bis(3-(isopropylimino)-2-methylbutan-2-olate)chromium(II), and bis(3-(isopropylimino)-2-methylbutan-2-olate)copper(II).
15. A method of forming a metal film on a substrate, the method comprising a deposition cycle including:
a) contacting a substrate with a vapor of a metal-containing compound described by formula I for a first predetermined pulse time to form a first modified surface:
wherein:
M is a metal selected from Groups 2 to 12 of the Periodic Table; and
R 1 , R 2 , R 3 , and R 4 are each independently H or C 1 -C 8 alkyl;
b) contacting the first modified surface with an acid for a second predetermined pulse time to form a second modified surface; and
c) contacting the second modified surface with an activating agent for a third predetermined pulse time to form a metal layer.
16. The method of claim 15 wherein the substrate is subject to a nucleation cycle prior to step a).
17. The method of claim 16 wherein the nucleation cycle comprises contacting the substrate with the vapor of the metal-containing compound described by formula I for a predetermined nucleation pulse time that is greater than the first predetermined pulse time and contacting the substrate with the vapor of the activating agent.
18. The method of claim 16 wherein the nucleation cycle comprises:
contacting the substrate with formic acid;
contacting the substrate with the vapor of the metal-containing compound described by formula I for a predetermined nucleation pulse time that is greater than the first predetermined pulse time; and
contacting the substrate with the vapor of the activating agent.