Sub-stoichiometric metal-oxide thin films

Patent metadata

Field	Value
Publication number	US-11646199-B2
Application number	US-202117323178-A
Country	US
Kind code	B2
Filing date	May 18, 2021
Priority date	Jul 19, 2019
Publication date	May 9, 2023
Grant date	May 9, 2023

Abstract

Embodiments of the present invention are directed to forming a sub-stoichiometric metal-oxide film using a modified atomic layer deposition (ALD) process. In a non-limiting embodiment of the invention, a first precursor and a second precursor are selected. The first precursor can include a metal and a first ligand. The second precursor can include the same metal and a second ligand. A substrate can be exposed to the first precursor during a first pulse of an ALD cycle. The substrate can be exposed to the second precursor during a second pulse of the ALD cycle. The second pulse can occur directly after the first pulse without an intervening thermal oxidant. The substrate can be exposed to the thermal oxidant during a third pulse of the ALD cycle.

First claim

What is claimed is:

1. A method for forming an electronic device, the method comprising:
forming a bottom layer;
forming a metal-sub-oxide film over the bottom layer, the metal-sub-oxide film formed by exposing the bottom layer to an atomic layer deposition (ALD) cycle, the ALD cycle comprising a first precursor pulse, a second precursor pulse, and an oxidant pulse, wherein the first precursor comprises a metal and a first ligand and the second precursor comprises the metal and a second ligand; and
forming a top electrode over the metal-sub-oxide film.

2. The method of claim 1 , wherein the bottom layer comprises a metal and the metal-sub-oxide film comprises an active area of a resistive random-access memory (RRAM).

3. The device of claim 1 , wherein the bottom layer comprises a semiconductor and a dielectric; and wherein the metal-sub-oxide film comprises a charge trapping layer of a floating gate flash memory.

4. The method of claim 1 , wherein the oxidant is a non-plasma based thermal oxidant.

5. The method of claim 1 , wherein during the first pulse the metal of the first precursor chemisorbs onto a surface of the substrate.

6. The method of claim 5 , wherein during the second pulse the metal of the second precursor chemisorbs onto a coated surface terminated by the first precursor ligands; and wherein the first ligand and the second ligand react during the second pulse to form one or more by-products.

7. An electronic device comprising:
a bottom layer;
a top electrode; and
a metal-sub-oxide film between the bottom layer and the top electrode, the metal-sub-oxide film formed by exposing the bottom layer to an atomic layer deposition (ALD) cycle, the ALD cycle comprising a first precursor pulse, a second precursor pulse, and an oxidant pulse, wherein the first precursor comprises a metal and a first ligand and the second precursor comprises the metal and a second ligand.

8. The device of claim 7 , wherein the bottom layer comprises a metal electrode and the metal-sub-oxide film comprises an active area of a resistive random-access memory (RRAM).

9. The device of claim 7 , wherein the bottom layer comprises a semiconductor and a dielectric layer; and wherein the metal-sub-oxide film comprises a charge trapping layer of a floating gate flash memory.

10. The device of claim 7 , wherein the metal comprises one or more of Hf, Ta, Zr, Al, La, and Si, the first ligand comprises a halide, and the second ligand comprises a metalorganic.

11. The device of claim 7 , wherein the metal comprises one or more of Hf, Ta, Zr, Al, La, and Si, the first ligand comprises a metalorganic, and the second ligand comprises a halide.

12. A metal-insulator-metal device comprising:
a bottom electrode comprising a first metal;
a top electrode comprising a second metal; and
a metal-sub-oxide film between the bottom electrode and the top electrode, the metal-sub-oxide film formed by exposing the bottom electrode to an atomic layer deposition (ALD) cycle, the ALD cycle comprising a first precursor pulse, a second precursor pulse, and an oxidant pulse, wherein the first precursor comprises a third metal and a first ligand and the second precursor comprises the third metal and a second ligand.

13. The device of claim 12 , wherein the bottom electrode comprises a metal-nitride and the metal-sub-oxide film comprises HfO 2-x or Ta 2 O 3-x .

14. The device of claim 12 , wherein the metal-sub-oxide film comprises one or more metal-metal bonds and one or more metal-nitride-metal bonds; and wherein the metal-sub-oxide film further comprises sub-oxide bonds coupled with organic and halide byproducts.

15. The device of claim 12 , wherein the metal-sub-oxide film comprises a sub-stochiometric film of a three-dimensional resistive random-access memory (RRAM), fin-type field effect transistor (finFET), or flash memory.

16. The device of claim 12 , wherein the metal comprises one or more of Hf, Ta, Zr, Al, La, and Si, the first ligand comprises a halide, and the second ligand comprises a metalorganic.

17. The device of claim 12 , wherein the metal comprises one or more of Hf, Ta, Zr, Al, La, and Si, the first ligand comprises a metalorganic, and the second ligand comprises a halide.

Assignees

• IBM
• Ulvac Inc

Inventors

• Rozen John
• Frank Martin Michael
• Ogawa Yohei

Classifications

• H10P14/6322

  Formation by thermal treatments (formation by plasma treatment H10P14/6319) · CPC title

• H10P14/6314

  of a metallic layer · CPC title

• H10P14/6339 Primary

  deposition by cyclic CVD, e.g. ALD, ALE or pulsed CVD · CPC title

• H10P14/69392

  the material containing hafnium, e.g. HfO2 · CPC title

• H10P14/69393

  the material containing tantalum, e.g. Ta2O5 · CPC title