USE OF SILICON OXYNITRIDE ARC FOR METAL LAYERS

• US 20010046791A1
• Filed: 12/08/1998
• Published: 11/29/2001
• Est. Priority Date: 12/08/1998
• Status: Active Grant

• Current Assignee: Lone Star Silicon Innovations LLC (Tanit Ventures Inc.)
• Original Assignee: Advanced Micro Devices, Inc.
• Inventors: YEDUR, SANJAY K., SUBRAMANIAN, RAMKUMAR, SINGH, BHANWAR, PLAT, MARINA V., TEMPLETON, MICHAEL K., RANGARAJAN, BHARATH, LYONS, CHRISTOPHER F.
• Granted Patent: US 6,326,231 B1
• Time in Patent Office: Days
• US Class Current: 438/786
• CPC Class Codes: H01L 21/022 the layer being a laminate, i.e. composed of sublayers, e.g. stacks of alternating high-k metal oxides adhesion layers or buffer layers H01L21/02304, H01L21/02362
• CPC Class Codes: H01L 21/02263 deposition from the gas or vapour phase
• CPC Class Codes: H01L 21/0276 using an anti-reflective coating anti-reflective coating for lithography in general G03F7/09
• CPC Class Codes: H01L 21/3143 composed of alternated layers or of mixtures of nitrides and oxides or of oxinitrides, e.g. formation of oxinitride by oxidation of nitride layers
• CPC Class Codes: H01L 21/3145 formed by deposition from a gas or vapour
• CPC Class Codes: H01L 21/32139 using masks

Abstract

In one embodiment, the present invention relates to a method of forming a silicon oxynitride antireflection coating over a metal layer, involving the steps of providing a semiconductor substrate comprising the metal layer over at least part of the semiconductor substrate; depositing a silicon oxynitride layer over the metal layer having a thickness from about 100 Å to about 1500 Å; and forming an oxide layer having a thickness from about 5 Å to about 50 Å over the silicon oxynitride layer to provide the silicon oxynitride antireflection coating. In another embodiment, the present invention relates to a method of reducing an apparent reflectivity of a metal layer having a first reflectivity in a semiconductor structure, involing forming a silicon oxynitride antireflection coating over the metal layer; wherein the silicon oxynitride antireflection coating formed over the metal layer has a second reflectivity and is formed by depositing silicon oxynitride on the metal layer by chemical vapor deposition and forming an oxide layer over the silicon oxynitride, and the difference between the first reflectivity and the second reflectivity is at least about 60%.

Claims

1. A method of forming a silicon oxynitride antireflection coating over a metal layer, comprising:

providing a semiconductor substrate comprising the metal layer over at least part of the semiconductor substrate;

depositing a silicon oxynitride layer over the metal layer having a thickness from about 100 Å

to about 1500 Å

; and

forming an oxide layer having a thickness from about 5 Å

to about 50 Å

over the silicon oxynitride layer to provide the silicon oxynitride antireflection coating.

2. The method of

claim 1

, wherein the metal layer comprises at least one of aluminum, copper, gold, nickel, palladium, platinum, silver, tantalum, titanium, tungsten, zinc, aluminum-copper alloys, aluminum alloys, copper alloys, titanium alloys, tungsten alloys, titanium-tungsten alloys, gold alloys, nickel alloys, palladium alloys, platinum alloys, silver alloys, tantalum alloys, zinc alloys, and metal silicides.

3. The method of

claim 1

, wherein the metal layer comprises at least one of aluminum, copper, aluminum-copper alloys, aluminum alloys and copper alloys.

4. The method of

claim 1

, wherein the oxide layer is formed by contacting the silicon oxynitride layer with oxygen plasma.

5. The method of

claim 1

, wherein the oxide layer is formed by contacting the silicon oxynitride layer with N₂O plasma.

6. The method of

claim 1

, wherein the oxide layer is formed by chemical vapor deposition techniques using SiH₄ and at least one of N₂O and O₂.

7. The method of

claim 1

, wherein the silicon oxynitride antireflection coating has a reflectivity of about 10% or less at a wavelength below about 248 nm.

8. A method of reducing an apparent reflectivity of a metal layer having a first reflectivity in a semiconductor structure, comprising forming a silicon oxynitride antireflection coating over the metal layer;

wherein the silicon oxynitride antireflection coating formed over the metal layer has a second reflectivity and is formed by depositing silicon oxynitride on the metal layer by chemical vapor deposition and forming an oxide layer over the silicon oxynitride, and the difference between the first reflectivity and the second reflectivity is at least about 60%.

9. The method of

claim 8

, wherein the metal layer comprises at least one of aluminum, copper, gold, nickel, palladium, platinum, silver, tantalum, titanium, tungsten, zinc, aluminum-copper alloys, aluminum alloys, copper alloys, titanium alloys, tungsten alloys, titanium-tungsten alloys, gold alloys, nickel alloys, palladium alloys, platinum alloys, silver alloys, tantalum alloys, zinc alloys, and metal silicides.

10. The method of

claim 8

, wherein second reflectivity is about 5% or less.

11. The method of

claim 8

, wherein the difference between the first reflectivity and the second reflectivity is determined at a wavelength below about 425 nm.

12. The method of

claim 8

, wherein the difference between the first reflectivity and the second reflectivity is determined at a wavelength below about 365 nm.

13. The method of

claim 8

, wherein the silicon oxynitride antireflection coating has a thickness from about 125 Å

to about 1400 Å

.

14. The method of

claim 8

, wherein the chemical vapor deposition is one of plasma enhanced chemical vapor deposition and low pressure chemical vapor deposition.

15. A method of processing a semiconductor substrate, comprising:

providing a semiconductor substrate comprising a metal layer having a reflectivity of at least 80%;

forming a silicon oxynitride antireflection coating over the metal layer having a thickness from about 100 Å

to about 1500 Å

, the silicon oxynitride antireflection coating comprising an oxide layer over a silicon oxynitride layer;

depositing a deep ultraviolet photoresist over the silicon oxynitride antireflection coating;

selectively irradiating the deep ultraviolet photoresist with electromagnetic radiation having a wavelength of about 248 nm or less; and

developing the deep ultraviolet photoresist.

16. The method of

claim 15

, wherein the metal layer comprises at least one of aluminum, copper, gold, nickel, palladium, platinum, silver, tantalum, titanium, tungsten, zinc, aluminum-copper alloys, aluminum alloys, copper alloys, titanium alloys, tungsten alloys, titanium-tungsten alloys, gold alloys, nickel alloys, palladium alloys, platinum alloys, silver alloys, tantalum alloys, zinc alloys, and metal silicides.

17. The method of

claim 15

, wherein the silicon oxynitride ARC is formed by depositing a silicon oxynitride layer by chemical vapor deposition and contacting the silicon oxynitride layer with at least one of a oxygen plasma and a N₂O plasma.

18. The method of

claim 17

, wherein the silicon oxynitride layer is deposited using one of plasma enhanced chemical vapor deposition and low pressure chemical vapor deposition.

19. The method of

claim 15

, wherein the electromagnetic radiation has a wavelength of at least one of about 365 nm, about 248 nm, about 193 nm and about 157 nm.

20. The method of

claim 15

, wherein the deep ultraviolet photoresist is developed to yield fine patterns on the order of 0.25 μ

m.