Volatile group 2 metal precursors
View Patent ↗A compound comprising one or more polyfunctionalized pyrrolyl anions coordinated to a metal selected from the group consisting of barium, strontium, magnesium, radium or calcium or mixtures thereof. Alternatively, one anion can be substituted with and a second non-pyrrolyl anion. Synthesis of the novel compounds and their use to form BST films is also contemplated.
1. A compound having the following formula:
where R 1 -R 16 are each individually acyl; formyl; amido; nitro; H; C 1 -C 10 primary, secondary or tertiary alkyl; C 1 -C 10 alkoxy; alkylamine; C 1 -C 10 alkyl functionalized with a heteroatom substituted ring structure selected from the group consisting of imidazole, pyrrole, pyridine, furan, pyrimidine, pyrazole; C 1 -C 10 alkyl functionalized with an amide group; C 1 -C 10 alkyl functionalized with an ester group and mixtures thereof; wherein (L) is a neutral ligand individually selected from the group consisting of aliphatic C 1 -C 20 ether or polyether; crownether; amine; poly amine; amide; poly amide; ester; polyester; aromatic ether; aromatic ester; aromatic amide; aromatic amine; pyridine; imidazole; pyridine; pyrazine; furan; pyrrole and mixtures thereof; M 2 and M 3 are individually selected from the group consisting of Ba, Sr, Ca, Ra or Mg; and each n independently=0-4.
2. The compound of claim 1 wherein R groups of one pyrrolyl anion are joined to the R groups of another pyrrolyl anion to connect the two anions together.
3. The compound of claim 1 having Formula B/C wherein R 1 to R 16 are each individually selected from the group consisting of H, tert-butyl, and tert-amyl; and M2 and M3 are individually selected from Ba or Sr.
4. The compound of claim 3 where R 1 to R 16 groups of pyrrolyl anions are joined to another R 1 to R 16 groups of pyrrolyl anions to connect the two anions together.
5. The compound of claim 3 selected from the group consisting of di-barium tetrakis(2,5-di-tert-butylpyrrolyl), di-strontium tetrakis(2,5-di-tent-amylpyrrolyl), and di-barium tetrakis(2,5-di-tert-amylpyrrolyl).
6. The compound of claim 5 comprising di-barium tetrakis(2,5-di-tert-butylpyrrolyl).
7. The compound of claim 5 comprising di-strontium tetrakis(2,5-di-tert-amylpyrrolyl).
8. The compound of claim 5 comprising di-barium tetrakis(2,5-di-tert-amylpyrrolyl).
9. A composition comprising a compound of claim 5 dissolved in at least one solvent selected from the group consisting of: an aliphatic hydrocarbon, an aromatic hydrocarbon, an aminoether, an ether, an ester, a nitrite, an amine, an organic amide, an alcohol, an imine, a carbodiimide, a ketone, an aldehyde, an amidine, a guandadine, an isourea, a glyme solvent having from 1 to 20 ethoxy —(C 2 H 4 O)— repeat units, an aminoether and mixtures thereof.
10. The composition of claim 9 comprising wherein the solvent is 2,2′-oxybis(N,N-dimethylethanamine) and the compound dissolved therein is di-barium tetrakis(2,5-di-tert-butylpyrrolyl).
11. A method of depositing a metal containing film by reacting a compound of claim 1 with an oxidant selected from the group consisting of water, alcohol, oxygen, ozone, nitrous oxide, nitrogen dioxide, hydrogen peroxide or combinations thereof to grow a metal containing film selected from the group consisting of barium oxide, strontium oxide, magnesium oxide, calcium oxide or radium oxide and mixtures thereof, using a reactor pressure between 0.001-1000 Torr and a temperature from 0-1000° C.