Narrow-channel accumulated-body bulk Si MOSFETs with wide-range dynamic threshold voltage tuning

摘要

Side-gated bulk Si nMOSFETs with Si3N4 shallow trench isolation (STI) have been previously demonstrated to have significantly reduced off-currents and improved subthreshold characteristics [1, 2]. The improvement is shown to be due to accumulation of the Si body with the holes as the polysilicon side-gate surrounding the body as a guard ring is negatively biased (Fig 1). The threshold voltage (VT) of the narrow channel devices can be dynamically controlled by the side-gate (Fig 2) voltage (Vside) in a wide range [2, 3], mainly due to the increase in the channel energy barrier (Fig. 3) [4].