Integration of multimodal transistors with transistor fabrication sequence

Abstract

A semiconductor device and fabrication method are described for integrating a nanosheet transistor with a multimodal transistor (MMT) in a single nanosheet process flow by processing a wafer substrate to form buried metal source/drain structures in an MMT region that are laterally spaced apart from one another and positioned below an MMT semiconductor channel layer before forming a transistor stack of alternating Si and SiGe layers in an FET region which are selectively processed to form gate electrode openings so that a first ALD oxide and metal layer are patterned and etched to form gate electrodes in the transistor stack and to form a channel control gate electrode over the MMT semiconductor channel layer, and so that a second oxide and conductive layer are patterned and etched to form a current control gate electrode over the MMT semiconductor channel layer and adjacent to the channel control gate electrode.