International Business Machines Corporation
Method for making superimposed transistors

Abstract:

A method for making first and second superimposed transistors, including: making, on a substrate, a stack of several semiconducting nanowires; etching a first nanowire so that a remaining portion of the first nanowire forms a channel of the first transistor; etching a second nanowire arranged between the substrate and the first nanowire, so that a remaining portion of the second nanowire forms a channel of the second transistor and has a greater length than that of the remaining portion of the first nanowire; making second source and drain regions in contact with ends of the remaining portion of the second nanowire; depositing a first dielectric encapsulation layer covering the second source and drain regions and forming vertical insulating portions; making first source and drain regions in contact with ends of the remaining portion of the first nanowire and insulated from the second source and drain regions by the vertical insulating portions.