METHOD OF FORMING MIXED RARE EARTH OXYNITRIDE AND ALUMINUM OXYNITRIDE FILMS BY ATOMIC LAYER DEPOSITION

• US 20070237699A1
• Filed: 03/31/2006
• Published: 10/11/2007
• Est. Priority Date: 03/31/2006
• Status: Active Grant

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Clark, Robert
• Granted Patent: US 8,097,300 B2
• Time in Patent Office: Days
• US Class Current: 423/263
• CPC Class Codes: C23C 16/308 Oxynitrides
• CPC Class Codes: C23C 16/45529 specially adapted for making a layer stack of alternating different compositions or gradient compositions
• CPC Class Codes: C23C 16/45531 specially adapted for making ternary or higher compositions
• CPC Class Codes: C23C 16/5096 Flat-bed apparatus
• CPC Class Codes: H01L 21/02178 the material containing aluminium, e.g. Al2O3
• CPC Class Codes: H01L 21/02192 the material containing at least one rare earth metal element, e.g. oxides of lanthanides, scandium or yttrium
• CPC Class Codes: H01L 21/02194 the material containing more than one metal element
• CPC Class Codes: H01L 21/02274 in the presence of a plasma [PECVD]
• CPC Class Codes: H01L 21/0228 deposition by cyclic CVD, e.g. ALD, ALE, pulsed CVD
• CPC Class Codes: H01L 21/3141 Deposition using atomic layer deposition techniques [ALD]
• CPC Class Codes: H01L 21/3142 of nano-laminates, e.g. alternating layers of Al203-Hf02
• CPC Class Codes: H01L 21/3145 formed by deposition from a gas or vapour
• CPC Class Codes: H01L 21/318 composed of nitrides

Abstract

A method is provided for depositing a gate dielectric that includes at least two rare earth metal elements in the form of an oxynitride or an aluminum oxynitride. The method includes disposing a substrate in a process chamber and exposing the substrate to a gas pulse containing a first rare earth precursor and to a gas pulse containing a second rare earth precursor. The substrate may also optionally be exposed to a gas pulse containing an aluminum precursor. Sequentially after each precursor gas pulse, the substrate is exposed to a gas pulse of an oxygen-containing gas, nitrogen-containing gas or an oxygen- and nitrogen-containing gas. In alternative embodiments, the first and second rare earth precursors may be pulsed together, and either or both may be pulsed together with the aluminum precursor. The first and second rare earth precursors comprise a different rare earth metal element. The sequential exposing steps may be repeated to deposit a mixed rare earth oxynitride or aluminum oxynitride layer with a desired thickness. Purge or evacuation steps may also be performed after each gas pulse.

Claims

1. A method for forming a mixed rare earth oxynitride or aluminum oxynitride film, comprising:

disposing a substrate in a process chamber; and

exposing the substrate to a gas pulse sequence to deposit a mixed rare earth oxynitride film or a mixed rare earth aluminum oxynitride film with a desired thickness, wherein the gas pulse sequence includes, in any order;

a) sequentially first, exposing the substrate to a gas pulse comprising a first rare earth precursor, and second, exposing the substrate to a gas pulse comprising an oxygen-containing gas, a nitrogen-containing gas, or an oxygen and nitrogen-containing gas;

b) sequentially first, exposing the substrate to a gas pulse comprising a second rare earth precursor, and second, exposing the substrate to a gas pulse comprising the oxygen-, nitrogen- or oxygen and nitrogen-containing gas, wherein the first and second rare earth precursors contain different rare earth metal elements; and

c) optionally, sequentially first, exposing the substrate to a gas pulse containing an aluminum precursor and second, exposing the substrate to a gas pulse containing the oxygen-, nitrogen- or oxygen and nitrogen-containing gas,

wherein each of a), b) and optionally c) are optionally repeated any number of desired times, and wherein the gas pulse sequence including a), b) and optionally c) is optionally repeated, in any order, any number of desired times to achieve the desired thickness.

2. The method of claim 1, wherein the rare earth metal elements in the first and second rare earth precursors are selected from Y, Lu, La, Ce, Pr, Nd, Sm, Eu, Gd, Th, Dy, Ho, Er, Tm, and Yb.

3. The method of claim 1, wherein the oxygen-, nitrogen- or oxygen and nitrogen-containing gases comprise one or more of:

O₂, H₂O, H₂O₂, ozone, plasma excited oxygen, NO, NO₂, N₂O, NH₃, N₂H₄, or plasma excited nitrogen.

4. The method of claim 1, wherein a) comprises:

alternating the first and second exposing steps a plurality of times.

5. The method of claim 1, wherein b) comprises:

alternating the first and second exposing steps a plurality of times.

6. The method of claim 1, wherein c) comprises:

alternating the first and second exposing steps a plurality of times

7. The method of claim 1, further comprising purging or evacuating the process chamber after at least one of a), b) or c).

8. The method of claim 1, further comprising purging or evacuating the process chamber between the first and second exposing steps in at least one of a), b) or c).

9. The method of claim 1, further comprising:

performing one or more additional exposure steps, wherein each additional exposure step comprises sequentially first, exposing the substrate to a gas pulse comprising an additional rare earth precursor, and second, exposing the substrate to a gas pulse comprising the oxygen-, nitrogen- or oxygen and nitrogen-containing gas, wherein each additional rare earth precursor contains a different rare earth metal element than the rare earth metal elements in the first and second rare earth precursors.

10. The method of claim 1, wherein the mixed rare earth oxynitride or aluminum oxynitride film has a thickness between about 5 and about 200 angstroms.

11. The method of claim 1, wherein the first exposing steps in a) and b) are performed concurrently and the second exposing steps in a) and b) are performed concurrently, whereby to sequentially first expose the substrate to a gas pulse comprising both the first and second rare earth precursors, and second expose the substrate to a gas pulse comprising the oxygen-, nitrogen- or oxygen and nitrogen-containing gas.

12. A method for forming a mixed rare earth oxynitride film, comprising:

a) disposing a substrate in a process chamber;

b) exposing the substrate to a gas pulse comprising a plurality of rare earth precursors containing at least two different rare earth metal elements;

c) exposing the substrate to a gas pulse of an oxygen-containing gas, a nitrogen-containing gas, or an oxygen and nitrogen-containing gas; and

d) repeating steps b) and c) a desired number of times to deposit a mixed rare earth oxynitride film with a desired thickness.

13. The method of claim 12, wherein the at least two rare earth metal elements are selected from Y, Lu, La, Ce, Pr, Nd, Sm, Eu, Gd, Th, Dy, Ho, Er, Tm, Yb.

14. The method of claim 12, wherein the oxygen-, nitrogen- or oxygen and nitrogen-containing gases comprise one or more of:

O₂, H₂O, H₂O₂, ozone, plasma excited oxygen, NO, NO₂, N₂O, NH₃, N₂H₄, or plasma excited nitrogen.

15. The method of claim 12, further comprising purging or evacuating the process chamber after at least one of the exposing steps.

16. The method of claim 12, wherein the mixed rare earth oxynitride film has a thickness between about 5 and about 200 angstrom.

17. A method for forming a mixed rare earth aluminum oxynitride film, comprising:

a) disposing a substrate in a process chamber;

b) sequentially first, exposing the substrate to a gas pulse comprising a plurality of rare earth precursors containing at least two different rare earth metal elements, and second, exposing the substrate to a gas pulse of an oxygen-containing gas, a nitrogen-containing gas, or an oxygen and nitrogen-containing gas;

c) sequentially first, exposing the substrate to a gas pulse containing an aluminum precursor and second, exposing the substrate to a gas pulse containing the oxygen-, nitrogen- or oxygen and nitrogen-containing gas; and

d) repeating steps b)-c) a desired number of times to deposit a mixed rare earth aluminum oxynitride film with a desired thickness.

18. The method of claim 17, wherein the at least two rare earth metal elements are selected from Y, Lu, La, Ce, Pr, Nd, Sm, Eu, Gd, Th, Dy, Ho, Er, Tm, and Yb.

19. The method of claim 17, wherein the oxygen-, nitrogen- or oxygen and nitrogen-containing gases comprise one or more of:

O₂, H₂O, H₂O₂, ozone, plasma excited oxygen, NO, NO₂, N₂O, NH₃, N₂H₄, or plasma excited nitrogen.

20. The method of claim 17, further comprising purging or evacuating the process chamber after at least one of b) or c).

21. The method of claim 17, further comprising purging or evacuating the process chamber between the first and second exposing steps in at least one of b) or c).

22. A method for forming a mixed rare earth aluminum oxynitride film, comprising:

a) disposing a substrate in a process chamber;

b) exposing the substrate to a gas pulse comprising a plurality of rare earth precursors containing at least two different rare earth metal elements and containing an aluminum precursor;

c) exposing the substrate to a gas pulse of an oxygen-containing gas, a nitrogen-containing gas, or an oxygen and nitrogen-containing gas;

d) repeating steps b)-c) a desired number of times to deposit a mixed rare earth aluminum oxynitride film with a desired thickness.

23. The method of claim 22, wherein the rare earth metal elements are selected from Y, Lu, La, Ce, Pr, Nd, Sm, Eu, Gd, Th, Dy, Ho, Er, Tm, and Yb.

24. The method of claim 22, wherein the oxygen-, nitrogen- or oxygen and nitrogen-containing gases comprise one or more of:

O₂, H₂O, H₂O₂, ozone, plasma excited oxygen, NO, NO₂, N₂O, NH₃, N₂H₄, or plasma excited nitrogen.

25. The method of claim 22, further comprising purging or evacuating the process chamber after at least one of the exposing steps.