The impact of an aluminum top layer on inductors integrated in an advanced CMOS copper backend

Author

Tiemeijer, L.F. ; Havens, R.J. ; Bouttement, Y. ; Pranger, H.J.

Author_Institution

Philips Electron., Eindhoven, Netherlands

Volume

25

Issue

11

fYear

2004

Firstpage

722

Lastpage

724

Abstract

The performance of inductors realized in various metal layer combinations available in an advanced CMOS process with a mixed copper-aluminum backend is compared. Due to the skin effect, the gain in performance is generally smaller than anticipated from the reduction in dc resistance. We show that beyond a certain frequency, adding an aluminum layer on top of a copper inductor stack actually degrades the inductor performance because the skin resistance of the top metal is enhanced.

Keywords

CMOS integrated circuits; inductors; integrated circuit reliability; skin effect; CMOS inductors; advanced CMOS copper backend; aluminum top layer; copper inductor stack; dc resistance reduction; inductor performance; integrated circuits; metal layer combinations; mixed copper-aluminum backend; quality factors; skin effect; skin resistance; Aluminum; CMOS process; Copper; Degradation; Electrical resistance measurement; Frequency measurement; Inductance; Inductors; Q factor; Skin; CMOS inductors; Integrated circuits; copper–aluminum backend; quality factors;

fLanguage

English

Journal_Title

Electron Device Letters, IEEE

Publisher

ieee

ISSN

0741-3106

Type

jour

DOI

10.1109/LED.2004.836797

Filename

1347207