Zirconium-doped tantalum oxide films

• US 8,765,616 B2
• Filed: 09/14/2012
• Issued: 07/01/2014
• Est. Priority Date: 08/02/2004
• Status: Active Grant

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Ahn, Kie Y., Forbes, Leonard
• Primary Examiner(s): Luu, Chuong A.
• Application Number:
  US13/618,212
• Publication Number:
  US 20130012034A1
• Time in Patent Office: 655 Days
• Field of Search: 438/784, 438/201, 438/211, 438/240, 438/257, 438/785, 438/778, 438/104, 438/85
• US Class Current: 438/784
• CPC Class Codes: C23C 16/405 of refractory metals or yttrium
• 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: H01L 21/02183 the material containing tantalum, e.g. Ta2O5
• CPC Class Codes: H01L 21/02189 the material containing zirconium, e.g. ZrO2
• CPC Class Codes: H01L 21/02194 the material containing more than one metal element
• CPC Class Codes: H01L 21/0228 deposition by cyclic CVD, e.g. ALD, ALE, pulsed CVD
• CPC Class Codes: H01L 21/02321 introduction of substances into an already existing insulating layer H01L21/02227 and subgroups take precedence
• CPC Class Codes: H01L 21/3141 Deposition using atomic layer deposition techniques [ALD]
• CPC Class Codes: H01L 21/31637 Deposition of Tantalum oxides, e.g. Ta2O5
• CPC Class Codes: H01L 21/31641 Deposition of Zirconium oxides, e.g. ZrO2

Abstract

Dielectric layers containing a zirconium-doped tantalum oxide layer, where the zirconium-doped tantalum oxide layer can be formed of one or more monolayers of tantalum oxide doped with zirconium, provide an insulating layer in a variety of structures for use in a wide range of electronic devices.

Claims

1. A method comprising:

forming tantalum oxide on a substrate using a self-limiting deposition process;

doping the tantalum oxide with zirconium at different times during the self-limiting deposition process such that a zirconium-doped tantalum oxide is formed; and

controlling the doping with zirconium to an amount such that the zirconium-doped tantalum oxide has a structure that does not differ significantly from an undoped tantalum oxide structure.

2. The method of claim 1, wherein doping the tantalum oxide with zirconium includes doping as elemental zirconium.

3. The method of claim 1, wherein doping the tantalum oxide with zirconium includes doping as zirconium oxide.

4. The method of claim 1, wherein forming zirconium-doped tantalum oxide includes forming an amorphous zirconium-doped tantalum oxide.

5. The method of claim 1, wherein forming the tantalum oxide including doping the tantalum oxide with zirconium is conducted at temperatures between about 250°

C. and about 325°

C.

6. The method of claim 1, wherein forming tantalum oxide on a substrate includes forming the tantalum oxide on a silicon substrate.

7. The method of claim 6, wherein forming the tantalum oxide including doping the tantalum oxide with zirconium is conducted at temperatures such that a silicon oxide interface is formed between the zirconium-doped tantalum oxide and the silicon substrate.

8. The method of claim 1, wherein the method includes providing a tantalum containing precursor directed to the substrate and providing a zirconium containing precursor directed to the substrate such that these precursors are directed to the substrate at non-overlapping periods.

9. The method of claim 8, wherein the method includes forming the tantalum oxide and doping the tantalum oxide with zirconium using precursors without chlorine.

10. The method of claim 9, wherein using precursors without chlorine includes using ZrI₄ as a zirconium-containing precursor.

11. The method of claim 1, wherein the method includes forming the zirconium-doped tantalum oxide as a gate insulator in a transistor.

12. The method of claim 8, wherein the method includes forming the zirconium-doped tantalum oxide as a gate insulator in a CMOS device.

13. The method of claim 1, wherein the method includes forming the zirconium-doped tantalum oxide as a dielectric between two electrodes of a capacitor.

14. The method of claim 1, wherein the method includes forming the zirconium-doped tantalum oxide as a gate insulator of a transistor in a memory array of a memory device.

15. The method of claim 1, wherein the method includes forming the zirconium-doped tantalum within a multi-component dielectric.

16. The method of claim 15, wherein forming the multi-component dielectric includes forming a nanolaminate dielectric.

17. The method of claim 16, wherein forming the nanolaminate dielectric includes forming the nanolaminate dielectric in a memory array of a NROM flash memory device.

18. The method of claim 1, wherein doping the tantalum oxide with zirconium includes pulsing a zirconium containing precursor during a portion of the time that a tantalum containing precursor is being pulsed.

19. The method of claim 1, wherein forming the zirconium-doped tantalum oxide includes performing a number of cycles of the self-limiting deposition process containing a number of tantalum processing sequences and a number of zirconium processing sequences, the number of tantalum processing sequences greater than the number of zirconium processing sequences.

20. The method of claim 19, wherein the number of zirconium processing sequences is performed as substitution for a portion of the tantalum sequences in the number of cycles.