VERTICAL FIELD-EFFECT TRANSISTOR DEVICES AND METHODS OF FORMING THE SAME

Vertical field-effect transistor (VFET) devices and methods of forming the same are provided. The methods may include forming a lower structure on a substrate. The lower structure may include first and second VFETs, a preliminary isolation structure between the first and second VFETs, and a gate liner on opposing sides of the preliminary isolation structure and between the preliminary isolation structure and the substrate. Each of the first and second VFETs may include a bottom source/drain region, a channel region and a top source/drain region sequentially stacked, and a gate structure on a side surface of the channel region. The preliminary isolation structure may include a sacrificial layer and a gap capping layer sequentially stacked. The methods may also include forming a top capping layer on the lower structure and then forming a cavity between the first and second VFETs by removing the sacrificial layer.