Tunneling field effect transistors and fabrication methods thereof are provided, which include: an integrated circuit device which includes a circuit input configured to receive an input voltage and a circuit output configured to deliver an output current. The integrated circuit also includes a circuit element having at least one tunneling field effect transistor (TFET). The circuit element connects the circuit input to the circuit output and is characterized by a V-shaped current-voltage diagram. The V-shaped current-voltage diagram describes the relationship between the input voltage of the circuit input and the output current of the circuit output.

Tunneling field effect transistors and fabrication methods thereof are provided, which include: an integrated circuit device which includes a circuit input configured to receive an input voltage and a circuit output configured to deliver an output current. The integrated circuit also includes a circuit element having at least one tunneling field effect transistor (TFET). The circuit element connects the circuit input to the circuit output and is characterized by a V-shaped current-voltage diagram. The V-shaped current-voltage diagram describes the relationship between the input voltage of the circuit input and the output current of the circuit output.

Tunneling field effect transistors and fabrication methods thereof are provided, which include: obtaining a gate structure disposed over a substrate structure; and providing a source region and a drain region within the substrate structure separated by a channel region, the channel region underlying, at least partially, the gate structure, and the providing including: modifying the source region to attain a narrowed source region bandgap; and modifying the drain region to attain a narrowed drain region bandgap, the narrowed source region bandgap and the narrowed drain region bandgap facilitating quantum tunneling of charge carriers from the source region or the drain region to the channel region. Devices including digital modulation circuits with one or more tunneling field effect transistor(s) are also provided.