Tunnel field effect transistor having anisotropic effective mass channel

A tunnel field effect transistor (TFET) device, comprising:

• a substrate;
• heavily doped source and drain regions disposed at opposite ends of the substrate separated by a channel region, where the channel region is intrinsic or lightly doped with doping of less than 1018/cm3 and the source and drain regions doped with doping of between about 1018/cm3 to about 1021/cm3, collectively forming a structure wherein the structure is PiN or NiP;
• and
• a source and drain terminal coupled to the source and drain regions, respectively,
• the channel region formed of an anisotropic material comprising a first substantially parallelogram portion having a first length defined along a longitudinal axis extending from the source region to the drain region and a second substantially parallelogram portion connected to the first substantially parallelogram portion having a second length defined along the longitudinal axis and larger than the first length, the TFET device having an effective channel length defined along the longitudinal axis that is an average of the first and second lengths.