 the combined capabilities of both 
 a nonplanar design and nonconventional 
 carrier injection mechanisms are subject to recent scientific investigations 
 to overcome the limitations of silicon metal oxide semiconductor field 
 effect transistors . in this letter 
 , we present a multimode field effect 
 transistors device using silicon nanowires that feature an axial n - type / intrinsic 
 doping junction . 
 a heterostructural device design is achieved by employing 
 a self - aligned nickel - silicide source contact . 
 the polymorph operation 
 of the dual - gate device enabling the configuration of one p- and two 
 n - type transistor modes is demonstrated . not only the type but also 
 the carrier injection mode can be altered by appropriate biasing of 
 the two gate terminals or by inverting the drain bias . with a combined 
 band - to - band and schottky tunneling mechanism , in p - type mode a subthreshold 
 swing as low as 143 
 mv / dec and an on / off ratio of up to 104 is found . as the device operates in forward bias , a nonconventional 
 tunneling transistor is realized , enabling an effective suppression 
 of ambipolarity . 
 depending on the drain bias , two different n - type 
 modes are distinguishable . 
 the carrier injection is dominated by thermionic 
 emission in forward bias with a maximum on / off ratio of up to 107 whereas in reverse bias a schottky tunneling mechanism dominates 
 the carrier transport . 
Supplementary Material