Organometallic compound and method
A class of organometallic compounds is provided. The compounds correspond in structure to Formula 1 (A)x-M-(OR3)4-x wherein: A is selected from the group consisting of —NR1R2, —N(R4)(CH2)nN(R5R6), —N═C(NR4R5)(NR6R7), OCOR1, halo and Y; R1 and R2 are independently selected from the group consisting of H and a cyclic or acyclic alkyl group having from 1 to 8 carbon atoms, with the proviso that at least one of R1 and R2 must be other than H; R4, R5, R6 and R7 are independently selected from the group consisting of H and an acyclic alkyl group having from 1 to 4 carbon atoms; Y is selected from the group consisting of a 3- to 13-membered heterocyclic radical containing at least one nitrogen atom; R3 is a cyclic or acyclic alkyl group having from 1 to 6 carbon atoms; M is selected from the group consisting of Si, Ge, Sn, Ti, Zr and Hf; x is an integer from 1 to 3; and n is an integer from 1 to 4. Compounds of the invention may be useful as precursors in chemical phase deposition processes such as atomic layer deposition (ALD), chemical vapour deposition (CVD), plasma assisted ALD and plasma assisted CVD. Methods of low temperature vapour phase deposition of metal oxide films, such as SiO2 films, are also provided.
1. A method for forming a metal oxide film by an atomic layer deposition (ALD) process, the ALD method comprising the steps of:
a. Providing at least one substrate having functional O—H groups covering the surface,
b. delivering to said substrate at least one compound of Formula 1 in the gaseous phase:
(A) x -M-(OR 3 ) 4−x
wherein:
A is selected from the group consisting of —NMe 2 ,
—N(R 4 )(CH 2 ) n N(R 5 R 6 ), —N═C(NR 4 R 5 )(NR 6 R 7 ), OCOR 1 , and Y;
R 1 is independently selected from the group consisting of a cyclic or acyclic alkyl group having from 1 to 8 carbon atoms;
R 4 , R 5 , R 6 and R 7 are independently selected from the group consisting of H and an acyclic alkyl group having from 1 to 4 carbon atoms;
Y is selected from the group consisting of a 3- to 13-membered heterocyclic radical containing at least one nitrogen atom;
R 3 is a cyclic or acyclic alkyl group having from 1 to 6 carbon atoms;
M is selected from the group consisting of Si, Ge, Sn;
x is an integer from 1 to 3; and
n is an integer from 1 to 4;
with the proviso that the compound of Formula 1 is not diacetoxy-ditbutoxysilane, and
with the proviso that when A is —NMe 2 , R 3 is methyl or ethyl,
c. purging the substrate with purge gas,
d. delivering to said substrate an oxygen source in the gaseous phase,
e. purging the substrate with purge gas,
f. repeating steps b) through e) until a desired thickness of metal oxide has been deposited.
2. The method of claim 1 , wherein M is Si.
3. The method of claim 1 , wherein A is selected from the group consisting of acetate, tetraethylguanidinyl, dimethylethylenediaminyl, and Y.
4. The method of claim 1 , wherein A is OCOR 1 , and wherein R 1 is independently selected from the group consisting of an acyclic alkyl group having from 1 to 4 carbon atoms.
5. The method of claim 3 , wherein A is Y, and wherein Y is selected from the group consisting of aziridinyl, azetidinyl, pyrrolidinyl, pyrrolyl, piperidinyl, pyridinyl, azepanyl, and azepinyl.
6. The method of claim 1 , wherein R 3 is an acyclic alkyl group having from 1 to 4 carbon atoms.
7. The method of claim 3 wherein A is pyrrolidinyl, and R 3 is selected from the group consisting of methyl and ethyl.
8. The method of claim 1 , wherein the oxygen source is selected from H 2 O in gaseous phase, H 2 O 2 in gaseous phase, O 2 , O 3 and hydrazine.
9. The method of claim 1 , wherein A is —NMe 2 .
10. The method of claim 4 , wherein R 1 is independently selected from the group consisting of methyl, ethyl and isobutyl.
11. The method of claim 5 , wherein Y is selected from the group consisting of aziridinyl, azetidinyl and pyrrolidinyl.
12. The method of claim 6 , wherein R 3 is selected from the group consisting of methyl and ethyl.
13. The method of claim 12 , wherein R 3 is a methyl group.
14. The method of claim 1 , wherein A is —N(R 4 )(CH 2 ) n N(R 5 R 6 ) or —N═C(NR 4 R 5 )(NR 6 R 7 ).
15. The method of claim 14 , wherein R 4 , R 5 , R 6 and R 7 are independently selected from the group consisting of methyl and ethyl.