A new test structure for parasitic resistance extraction in bipolar transistors

Design issues concerning the layout of the dual base terminal test structure are discussed and a new test structure is proposed which allows fast and simple extraction of the emitter, base and collector resistances in bipolar transistors. The structure is designed as a regular transistor, equipped with two base terminals for base and emitter resistance extraction and two collector terminals for collector resistance extraction. The structure has been successfully implemented in both double poly-Si and single poly-Si technologies. The extracted resistances agree well with those extracted by other methods. It is also shown that the use of an additional collector contact enables monitoring of the onset of the base push-out (Kirk) effect.