Impact ionization and tunneling operations in charge-plasma dopingless device

In this paper, we present the impact ionization and tunneling operations in a newly designed dopingless device. Our proposed device functions selectively—as either a p-channel impact-ionization MOSFET (p-IMOS) or an n-channel tunneling field-effect transistor (n-TFET)—according to the bias conditions. To realize the dopingless device, the charge-plasma effect is employed to induce n- or p-type regions without any doping process, by choosing an electrode metal with an appropriate work function. The band diagrams, I–V characteristics, subthreshold swings (SS), and carrier-concentration profiles of the device under the p-IMOS and n-TFET operation modes are analyzed in our study, using a commercial device simulator. The device yields an extremely low SS of 0.53 mV/dec under the p-IMOS operation mode. It also exhibits a low off-current of approximately 10−14 A/μm and a high ION/IOFF of approximately 108, under the n-TFET operation mode.