Vertical MOSFET with horizontally graded channel doping

摘要

Body effects in vertical MOSFET transistors are considerably reduced and other device parameters are unaffected in a vertical transistor having a threshold implant with a peak at the gate and an implant concentration distribution that declines rapidly away from the gate to a plateau having a low p-well concentration value. A preferred embodiment employs two body implants-an angled implant having a peak at the gate that sets the Vt and a laterally uniform low dose implant that sets the well dopant concentration.