Title :
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
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;
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2004.836797
