Cmos device, method of manufacturing cmos device, and semiconductor memory device including cmos device

Abstract

A CMOS device, and a method of manufacturing the same, includes a semiconductor substrate and a trench formed in the semiconductor substrate. The CMOS device also includes an oxide semiconductor layer disposed in the trench, the oxide semiconductor layer including a source region, a drain region, and a channel region between the source region and the drain region. The CMOS device further includes a buffer layer between the oxide semiconductor layer and the semiconductor substrate, a gate insulating layer on the oxide semiconductor layer, a gate electrode disposed on the gate insulating layer over the channel region of the oxide semiconductor layer, and impurities distributed in each of the source region and the drain region of the oxide semiconductor layer.