Analysis of abnormal transconductance in body-tied partially-depleted silicon-on-insulator n-MOSFETs

Abstract

This research investigates the mechanism of abnormal transconductance (Gm) and abnormal charge pumping current (I-CP) in body-tied partially-depleted silicon-on-insulator n-channel metal-oxide-semiconductor field effect transistors. The I-CP second hump region increases with channel length, yet is not affected by channel width. The cross-sectional view of the L-gate structure along the width direction demonstrates that a part of the poly gate area near the body contact is covered by a P+ implant, inducing a parasitic channel under the P+ poly gate. This parasitic channel leads to the abnormal Gm and I-CP hump, and such mechanism is further verified by body floating devices.