Investigation and optimization of electro-thermal performance of Double Gate-All-Around MOSFET

The Double Gate-All-Around (DGAA) MOSFET and GAA NWFET are compared and analyzed from both electrical and thermal perspectives under four different conditions by adjusting the channel radius of the NWFET (R_GAA). DGAA MOSFET is found to easier form volume inversion than GAA NWFET, and has the advantage of better gate controllability and drivability and the primary concern of worse heat dissipation efficiency. Hetero-Gate-Dielectric (HGD) structure, channel design and spacer engineering are adopted to weaken the serious SHEs in DGAA MOSFET while maintaining a good SCEs immunity. Results show that the DGAA MOSFET with the single-k Al₂O₃ spacer can generate a better trade-off between electrical and thermal performance than other spacer combinations. In addition, the improvement in thermal performance of DGAA MOSFET by the HGD structure is relatively limited. Compared with GAA NWFET without stacking, the optimized DGAA MOSFET with single-k Al₂O₃ spacer, appropriate channel thickness (T_ch = 5 nm) to form volume inversion and underlap channel (L_un = 4 nm) has better electrical characteristics whose drivability improves at least twice with similar R_th.