Semiconductor device with six transistors forming a nand circuit

Abstract

A semiconductor device has a small area and constitutes a CMOS 3-input NAND circuit by using surrounding gate transistors (SGTs) that are vertical transistors. In a 3-input NAND circuit including six MOS transistors arranged in a line, the MOS transistors constituting the NAND circuit have the following configuration. Planar silicon layers are disposed on a substrate. The drain, gate, and source of the MOS transistors are arranged in a vertical direction, and the gate surrounds a silicon pillar. The planer silicon layers include a first active region having a first conductivity type and a second active region having a second conductivity type. The first and second active regions are connected to each other via a silicide layer disposed on surfaces of the planar silicon layers. In this way, a semiconductor device constituting a NAND circuit with a small area is provided.