Vertical field effect transistor having two-dimensional channel structure

A vertical field effect transistor (VFET) comprising:

• a substrate including a first source/drain region;
• a channel structure protruding from the first source/drain region and configured to serve as a channel, the channel structure having a two-dimensional shape in a plan view, the channel structure having an opening at at least one side thereof,
• a gate structure horizontally surrounding the channel structure;
• and
• a second source/drain region on the channel structure.

A vertical field effect transistor (VFET) comprising:

• a first source/drain region included in a substrate;
• a channel structure vertically protruding from the first source/drain region of the substrate and configured to serve as a channel, the channel structure having a two-dimensional structure in a plan view, the channel structure having an opening at at least one side thereof, the channel structure including two or more first portions extending in a first direction and at least one second portion connecting the two or more first portions;
• a gate structure horizontally surrounding the channel structure;
• and
• a second source/drain region on the channel structure, the second source/drain region facing the first source/drain region with the channel structure vertically interposed therebetween.