Improved subthreshold characteristics in tunnel field-effect transistors using shallow junction technologies

Si n–i–p tunnel field-effect transistor (TFET) fabricated by plasma implantation and laser annealing is proposed. This TFET has sharp lateral source doping profile, which can reduce the tunneling distance and improve carrier tunneling. Enhanced on-current (12 μA/μm) and improved ION/IOFF ratio (6 × 106) are observed in this TFET [VDS = (VGS − VBTBT) = −1.1 V; VBTBT is the VGS at the lowest subthreshold current observed at given VDS] at T = 300 K. In addition, the TFET fabricated by laser annealing shows improved subthreshold characteristics, reduced tunneling resistance and smaller threshold voltage than TFET fabricated by rapid thermal annealing. Low-temperature measurements of this TFET were also performed to confirm the carrier injection mechanism of band-to-band tunneling. Plasma implantation and laser annealing are effective and suitable to be applied in current CMOS technology for low power devices.

► To enhance carrier tunneling, getting a sharp lateral source profile is important. ► Si TFET fabricated by plasma implantation and laser annealing is proposed. ► Enhanced subthreshold and output characteristics are observed in this TFET. ► Compare to other TFETs, this TFET is efficient to current CMOS technology.