Dismiss
The Prior Art Database and Publishing service will be updated on Sunday, February 25th, from 1-3pm ET. You may experience brief service interruptions during that time.
Browse Prior Art Database

The Use of Contact Pad Structure With Diffusion Barrier Metal Column Surrounding the Fine Line Interconnect

IP.com Disclosure Number: IPCOM000038700D
Original Publication Date: 1987-Feb-01
Included in the Prior Art Database: 2005-Jan-31
Document File: 2 page(s) / 49K

Publishing Venue

IBM

Related People

Kwok, TY: AUTHOR [+2]

Abstract

This publication describes a technique to improve the electromigration life-time by reducing extrusion-shorts in fine line interconnects and electrical opens on anode contact pads. In the Al-Cu fine line interconnects, electromigration-induced failure mainly comes from void-opens because it occurs at an earlier time than extrusion-shorts. By using the A1-transition metal intermetallic sandwich layered structure (e.g., A1-Cu/Hf/A1-Cu) in AMET fine line interconnects, the electromigration-induced void-open failure mechanism has been improved due to the microstructure modification and the redundant A1-intermetallic layer. As a result, the extrusion-short becomes the dominated mechanism in the fine line interconnects.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 66% of the total text.

Page 1 of 2

The Use of Contact Pad Structure With Diffusion Barrier Metal Column Surrounding the Fine Line Interconnect

This publication describes a technique to improve the electromigration life-time by reducing extrusion-shorts in fine line interconnects and electrical opens on anode contact pads. In the Al-Cu fine line interconnects, electromigration- induced failure mainly comes from void-opens because it occurs at an earlier time than extrusion-shorts. By using the A1-transition metal intermetallic sandwich layered structure (e.g., A1-Cu/Hf/A1-Cu) in AMET fine line interconnects, the electromigration-induced void-open failure mechanism has been improved due to the microstructure modification and the redundant A1- intermetallic layer. As a result, the extrusion-short becomes the dominated mechanism in the fine line interconnects. It has been found that the extrusion- short occurs at the time when there is a large A1-Cu depletion area in the cathode contact pad. In addition, electrical-open failure is also observed near and in the anode contact pad. All these indicate that the contact pad serves as the source or the sink for A1-Cu being transported along the fine line interconnect out of or into the connect pad. The Cr/Cu/Au diffusion barrier metals used in BLM provide good electromigration resistance (Fig. 1). Thus, the contact pad structure can be designed in such a way (Fig. 2) that allows a diffusion barrier metal column (e.g., Cr/Cu/Au in BLM, or Cr+CrOx, or Ti-W) in...