Improvement in Self-Heating Characteristic by Incorporating Hetero-Gate-Dielectric in Gate-All-Around MOSFETs

For improving self-heating effects (SHEs) in gate-all-around metal-oxide-semiconductor field-effect transistors (GAA MOSFETs), hetero-gate-dielectric (HGD) is utilized. The HGD consists of hafnium dioxide (HfO 2 ) and silicon dioxide (SiO 2 ), which has high thermal conductivity, hence SHEs are improved. In order to validate the HGD, technology computer-aided design (TCAD) simulation is performed through Synopsys Sentaurus three-dimensional (3D) tool. As a result, when the HGD is adopted in GAA MOSFETs, SHEs can be significantly improved from 498 K to 415 K. In addition, suppression of gate current, more than 2 orders, is also achieved because of bigger bandgap of SiO 2 in HGD. Consequently, this structure takes advantage of higher thermal conductivity and bigger bandgap of SiO 2 , and higher permittivity of HfO 2 for improving SHEs and gate leakage current.