Diffusion Barrier for Semiconductor Device and Method

Patent metadata

Field	Value
Publication number	US-2022367376-A1
Application number	US-202217815026-A
Country	US
Kind code	A1
Filing date	Jul 26, 2022
Priority date	Jun 11, 2020
Publication date	Nov 17, 2022
Grant date	—

Abstract

A method includes forming an insulating layer over a conductive feature; etching the insulating layer to expose a first surface of the conductive feature; covering the first surface of the conductive feature with a sacrificial material, wherein the sidewalls of the insulating layer are free of the sacrificial material; covering the sidewalls of the insulating layer with a barrier material, wherein the first surface of the conductive feature is free of the barrier material, wherein the barrier material includes tantalum nitride (TaN) doped with a transition metal; removing the sacrificial material; and covering the barrier material and the first surface of the conductive feature with a conductive material.

First claim

What is claimed is:

1 . A structure comprising:
a first conductive feature in a first dielectric layer; an etch stop layer over the first conductive feature; a second dielectric layer over the etch stop layer; and a second conductive feature extending through the second dielectric layer and the etch stop layer to physically contact the first conductive feature, wherein the second conductive feature comprises:
a barrier layer extending continuously on sidewalls of the second dielectric layer and on sidewalls of the etch stop layer, wherein the barrier layer comprises a layer of a transition metal between a first layer of a metal nitride and a second layer of the metal nitride, wherein the metal nitride is free of the transition metal; and
a conductive filling material over the barrier layer, wherein the conductive filling material extends between the barrier layer and the first conductive feature.

2 . The structure of claim 1 , wherein the barrier layer partially covers a sidewall of the etch stop layer.

3 . The structure of claim 1 , wherein the conductive filling material physically contacts sidewalls of the etch stop layer.

4 . The structure of claim 1 , wherein the transition metal is ruthenium.

5 . The structure of claim 1 , wherein the layer of the transition metal has a thickness in the range between 1 Å and 6 Å.

6 . The structure of claim 1 , wherein a bottom of the barrier layer is vertically separated from a top of the first conductive feature.

7 . The structure of claim 1 , wherein the metal nitride is tantalum nitride.

8 . The structure of claim 1 , wherein the second conductive feature comprises a lower portion and an upper portion, wherein the lower portion has a smaller width than the upper portion.

9 . A device comprising:
a first conductive feature over a substrate; a first insulating layer over the first conductive feature; and a via on the first conductive feature and within the first insulating layer, wherein the via comprises:
a conductive material; and
a barrier layer between the conductive material and the first insulating layer, wherein the barrier layer comprises a layer of a nitride of a first transition metal, wherein the barrier layer is doped throughout by a second transition metal different from the first transition metal.

10 . The device of claim 9 , further comprising an etch stop layer between the first conductive feature and the first insulating layer.

11 . The device of claim 10 , wherein the barrier layer physically contacts the etch stop layer.

12 . The device of claim 9 , wherein the first conductive feature is free of the barrier layer.

13 . The device of claim 9 , wherein the first transition metal is tantalum.

14 . The device of claim 9 , wherein the second transition metal is cobalt.

15 . The device of claim 9 , wherein the second transition metal is ruthenium.

16 . The device of claim 9 , wherein the doping concentration of the second transition metal is between 5% atomic percent and 30% atomic percent.

17 . A device comprising:
a first conductive feature in a first dielectric layer; an etch stop layer over the first conductive feature; a second dielectric layer over the etch stop layer; and a second conductive feature in the second dielectric layer, the second conductive feature comprising:
a first layer of a metal nitride;
a first layer of a transition metal on the first layer of the metal nitride, wherein the transition metal is a different metal than the metal of the metal nitride;
a second layer of the metal nitride on the first layer of the transition metal; and
a conductive filling material over the second layer of the metal nitride, wherein the conductive filling material physically contacts the first conductive feature.

18 . The device of claim 17 further comprising a second layer of the transition metal on the second later of the metal nitride.

19 . The device of claim 18 , wherein the first layer of the transition metal has a different thickness than the second layer of the transition metal.

20 . The device of claim 17 , wherein the first layer of the transition metal has a thickness in the range of 10 Å to 60 Å.

Assignees

• Taiwan Semiconductor Mfg Co Ltd

Inventors

• Kuo Chia-Pang
• Shih Huan-Yu
• Chen Wen-Hsuan
• Tsai Cheng-Lun
• Lee Ya-Lien
• Weng Cheng-Hui
• Lin Chun-Chieh
• Su Hung-Wen
• Liu Yao-Min

Classifications

• H10P14/3216

  Nitrides · CPC title

• H10P14/24

  using chemical vapour deposition [CVD] · CPC title

• H10W20/435

  Cross-sectional shapes or dispositions of interconnections · CPC title

• H10W20/076

  in via holes or trenches · CPC title

• H10W20/42

  Vias, e.g. via plugs · CPC title