Preparation of Lanthanide-Containing Precursors and Deposition of Lanthanide-Containing Films

• US 20090302434A1
• Filed: 06/05/2009
• Published: 12/10/2009
• Est. Priority Date: 06/05/2008
• Status: Active Grant

• Current Assignee: American Air Liquide Incorporated (L'Air Liquide SA)
• Original Assignee: American Air Liquide Incorporated (L'Air Liquide SA)
• Inventors: Dussarrat, Christian, Pallem, Venkateswara R.
• Granted Patent: US 8,283,201 B2
• Time in Patent Office: Days
• US Class Current: 257/632
• CPC Class Codes: C07C 257/14 having carbon atoms of amidino groups bound to acyclic carbon atoms
• CPC Class Codes: C07F 17/00 Metallocenes
• CPC Class Codes: C23C 16/18 from metallo-organic compounds
• CPC Class Codes: C23C 16/409 of the type ABO3 with A representing alkali, alkaline earth metal or lead and B representing a refractory metal, nickel, scandium or a lanthanide
• CPC Class Codes: C23C 16/45531 specially adapted for making ternary or higher compositions
• CPC Class Codes: H01L 21/02192 the material containing at least one rare earth metal element, e.g. oxides of lanthanides, scandium or yttrium

Abstract

Methods and compositions for depositing rare earth metal-containing layers are described herein. In general, the disclosed methods deposit the precursor compounds comprising rare earth-containing compounds using deposition methods such as chemical vapor deposition or atomic layer deposition. The disclosed precursor compounds include a cyclopentadienyl ligand having at least one aliphatic group as a substituent and an amidine ligand.

Claims

1. A composition comprising a lanthanide-containing precursor of the general formula:

Ln(R¹Cp)_m(R²—

N—

C(R⁴)═

N—

R²)_n,

wherein;

Ln is a lanthanide metal having an ionic radius from approximately 0.75 Å

to approximately 0.94 Å

, a 3+ charge, and a coordination number of 6;

R¹ is selected from the group consisting of H and a C₁-C₅ alkyl chain;

R² is selected from the group consisting of H and a C₁-C₅ alkyl chain;

R⁴ is selected from the group consisting of H and Me;

n and m range from 1 to 2; and

the precursor has a melting point below approximately 105°

C.

2. The composition of claim 1, wherein Ln is selected from the group consisting of Lu, Gd, Tb, Dy, Ho, Er, Tm, and Yb.

3. The composition of claim 2, wherein Ln is selected from the group consisting of Er and Yb.

4. The composition of claim 1, wherein R¹ is selected from the group consisting of Me, Et, and iPr.

5. The composition of claim 1, wherein R² is selected from the group consisting of iPr and tBu.

6. A method for depositing a lanthanide-containing film on a semiconductor substrate, the method comprising:

a) providing a substrate;

b) providing the lanthanide-containing precursor of claim 1; and

c) depositing a lanthanide-containing film on the substrate.

7. The method of claim 6, further comprising depositing the lanthanide-containing film on the substrate at a temperature between about 150°

C. and about 600°

C.

8. The method of claim 6, further comprising depositing the lanthanide-containing film on the substrate at a pressure between about 0.5 mTorr and about 20 Torr.

9. The method of claim 6, wherein the lanthanide-containing precursor is a liquid at a temperature below about 70°

C.

10. The method of claim 9, wherein the lanthanide-containing precursor is a liquid at a temperature below about 40°

C.

11. The method of claim 6, wherein the lanthanide-containing film is selected from the group consisting of Ln₂O₃, (LnLn′

)O₃, Ln₂O₃-Ln′

₂O₃, LnSi_xO_y, LnGe_xO_y, (Al, Ga, Mn)LnO₃, HfLnO_x, and ZrLnO_x, wherein Ln and Ln′

are different.

12. The method of claim 11, wherein the lanthanide-containing film is selected from the group consisting of HfErO_x, ZrErO_x, HfYbO_x, and ZrYbO_x.

13. The method of claim 6, wherein the lanthanide-containing precursor has the general formula selected from the group consisting of Ln(R¹Cp)₂(N^Z-fmd), Ln(R¹Cp)₂(N^Z-amd), Ln(R¹Cp)(N^Z-fmd)₂, and Ln(R¹Cp)(N^Z-amd)₂, wherein Ln is selected from the group consisting of Y, Gd, Dy, Er, and Yb;

R¹ is selected from the group consisting of Me, Et, and iPr; and

Z is iPr or tBu.

14. A method of forming a lanthanide-containing film on a substrate, the method comprising the steps of:

providing a reactor having at least one substrate disposed therein;

introducing at least one lanthanide-containing precursor of claim 1 into the reactor; and

contacting the lanthanide-containing precursor and the substrate to form a lanthanide-containing layer on at least one surface of the substrate using a deposition process.

15. The method of claim 14, further comprising the steps of:

a) providing at least one reactant species into the reactor, wherein said reactant species is an oxygen containing fluid; and

b) reacting said lanthanide-containing precursor with said reactant species.

16. The method of claim 15, wherein the at least one reactant species is selected from the group consisting of O₂, O₃, H₂O, H₂O₂, acetic acid, formalin, para-formaldehyde, and combinations thereof.

17. The method of claim 15, wherein the lanthanide-containing precursor and the reactant species are either introduced at least partially simultaneously as in a chemical vapor deposition process, or are introduced at least partially sequentially as in an atomic layer deposition process.

18. The method of claim 15, further comprising introducing a metal precursor into the reactor, wherein the metal precursor is different than the lanthanide-containing precursor and depositing at least part of the metal precursor to form the lanthanide-containing layer on the one or more substrates.

19. The method of claim 18, wherein a metal of the metal precursor is selected from the group consisting of Hf, Si, Al, Ga, Mn, Ti, Ta, Bi, Zr, Pb, Nb, Mg, Sr, Y, Ba, Ca, a lanthanide, and combinations thereof.

20. The method of claim 14, wherein the deposition process is a chemical vapor deposition process.

21. The method of claim 14, wherein the deposition process is an atomic layer deposition process having a plurality of deposition cycles.

22. The method of claim 14, wherein the lanthanide-containing precursor has the general formula selected from the group consisting of Ln(R¹Cp)₂(N^Z-fmd), Ln(R¹Cp)₂(N^Z-amd), Ln(R¹Cp)(N^Z-fmd)₂, and Ln(R¹Cp)(N^Z-amd)₂, wherein Ln is selected from the group consisting of Y, Gd, Dy, Er, and Yb;

R¹ is selected from the group consisting of Me, Et, and iPr; and

Z is iPr or tBu.

23. A lanthanide-containing film coated substrate comprising the product of the method of claim 14.