Hybrid metal interconnects with a bamboo grain microstructure

Patent metadata

Field	Value
Publication number	US-9754885-B1
Application number	US-201615245951-A
Country	US
Kind code	B1
Filing date	Aug 24, 2016
Priority date	Mar 4, 2016
Publication date	Sep 5, 2017
Grant date	Sep 5, 2017

Abstract

A method of forming an interconnect with a bamboo grain microstructure. The method includes forming a conductive filler layer in a trench of an insulating layer to a predetermined depth such that an aspect ratio of a top portion of the trench is reduced to a threshold level, depositing a metal layer over the conductive filler layer in the top potion of the trench, the metal layer having a plurality of small grains, and annealing the metal layer to provide a bamboo grain microstructure having larger grains than grain boundaries of the plurality of small grains.

First claim

What is claimed is:

1. An interconnect having a bamboo grain microstructure, comprising:
a conductive filler layer formed in a bottom portion of a trench of an insulating layer to a predetermined depth to provide a reduced aspect ratio in a top portion of the trench, the predetermined depth being less than a full depth of the trench; and
a metal layer formed in the top potion of the trench over the conductive filler layer, the metal layer having a bamboo grain microstructure.

2. The interconnect of claim 1 , wherein the reduced aspect ratio of the top portion of the trench is approximately 1:1 or less.

3. The interconnect of claim 1 , further comprising at least one conformal layer formed in the trench such that the at least one conformal layer protects the insulating layer, the at least one conformal layer being disposed between the insulating layer and the conductive filler layer.

4. The interconnect of claim 1 , further comprising a seed layer formed in the trench such that the seed layer is disposed between the conductive filler layer and the metal layer.

5. The interconnect of lair 1 , further comprising at least one cap layer formed over the metal layer.

6. The interconnect of claim 1 , wherein the metal layer includes a material different than the conductive filler layer.

Assignees

• IBM

Inventors

• Briggs Benjamin D
• Clevenger Lawrence A
• Rizzolo Michael
• Yang Chih-Chao

Classifications

• H10W20/4437

  the principal metal being a transition metal · CPC title

• H10W20/077

  on sidewalls or on top surfaces of conductors (H10W20/076 takes precedence) · CPC title

• H10W20/037

  the barrier, adhesion or liner layers being on top of a main fill metal · CPC title

• H10W20/0526

  by thermal treatment thereof · CPC title

• H10W20/425

  Barrier, adhesion or liner layers · CPC title