Electromigration characteristics of copper interconnects

Author

Tao, Jiang ; Cheung, Nathan W. ; Hu, Chenming

Author_Institution

Dept. of Electr. Eng. & Comput. Sci., California Univ., Berkeley, CA, USA

Volume

14

Issue

5

fYear

1993

fDate

5/1/1993 12:00:00 AM

Firstpage

249

Lastpage

251

Abstract

The electromigration characteristics of electroless plated copper interconnects have been investigated under DC and time-varying current stressing. A scheme for selected electroless Cu plating by using 150-AA Co as the seeding layer is reported. The Cu DC and pulse-DC lifetimes are found to be one and two orders of magnitude longer than that of Al-4% Cu/TiW and Al-2% Si interconnects at 275 degrees C, and the extracted Cu lifetime at 75 degrees C is about three and five orders of magnitude longer than that of Al-4% Cu/TiW and Al-2% Si, respectively. As previously reported for Al metallization, the Cu bipolar lifetimes were found to be orders of magnitude longer than their DC lifetimes under the same peak stressing current density because of the partial recovery of electromigration damage during the opposing phases of bipolar stressing.<>

Keywords

copper; electroless deposition; electromigration; metallisation; Co seeding layer; DC lifetimes; DC stressing; bipolar lifetimes; electroless plated Cu interconnects; electromigration characteristics; electromigration damage recovery; pulse-DC lifetimes; time-varying current stressing; Adhesives; Artificial intelligence; Conductivity; Copper alloys; Current density; Dry etching; Electromigration; Metallization; Palladium; Testing;

fLanguage

English

Journal_Title

Electron Device Letters, IEEE

Publisher

ieee

ISSN

0741-3106

Type

jour

DOI

10.1109/55.215183

Filename

215183