Copper bump barrier cap to reduce electrical resistance

A controlled collapse chip connection (C4) comprises a copper metal C4 bump formed on an integrated circuit substrate, where the C4 bump includes a metal barrier cap to prevent electromigration of the copper metal. The barrier cap is formed from nickel or cobalt and it can either be formed on a top...

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Bibliographic Details
Main Authors ZHONG TING, NIU BAOHUA, ANDIDEH EBRAHIM, RAMANATHAN SHRIRAM, LEATHERMAN GERALD S
Format Patent
LanguageEnglish
Published 01.03.2007
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Summary:A controlled collapse chip connection (C4) comprises a copper metal C4 bump formed on an integrated circuit substrate, where the C4 bump includes a metal barrier cap to prevent electromigration of the copper metal. The barrier cap is formed from nickel or cobalt and it can either be formed on a top surface of the C4 bump or it can encapsulate the C4 bump. A method of forming the C4 bump with the barrier cap comprises providing an integrated circuit substrate, depositing a photoresist layer on a top surface of the integrated circuit substrate, exposing and developing the photoresist layer to form an opening, depositing copper metal into the opening to form a C4 bump, plating a metal barrier layer onto a surface of the C4 bump, and stripping the photoresist layer.
Bibliography:Application Number: US20050212999