SEMICONDUCTOR DEVICE AND ITS MANUFACTURE

摘要

PURPOSE:To seek to improve the resistance to hot carriers without spoiling performance of an element respecting MOS transistor by so forming a gate electrode as to have different work functions at both ends to the longitudinal direction of a channel. CONSTITUTION:A gate electrode 3 having different work functions at both end to the longitudinal direction of a channel is formed on a gate insulating film 2 formed at the surface of a semiconductor substrate 1, and with this gate electrode 3 as a mask ions are implanted into the semiconductor substrate 1 so as to form sources 7s and 5s and drains 5d and 7d. In the Lightly Doped Drain(LDD) structure by this constitution, the low impurity concentration region with high resistance can be made easy to partially form an inversion layer by changing the work function of the gate electrode 3, and the lowering of mutual conductance can be prevented. Hereby, the resistance to hot carriers can be improved without spoiling the performance of an element respecting a MOS transistor.