A gallium nitride (GaN) based gate all-around field-effect transistor (GAA-FET) for applications in ultra-fast circuits

Abstract

A gallium nitride (GaN)-based gate all-around field-effect transistor (GAA-FET) for ultrafast circuit applications, the device comprising: a gate electrode with a gate length of 7 nanometers; a gallium nitride (GaN) channel region doped with n dopants at a concentration of 1 × 10¹⁶ cm⁻³; a gate stack structure consisting of a silicon dioxide layer and a hafnium dioxide layer, the gate stack structure completely enclosing the entire perimeter of the gallium nitride channel region; a source and drain region with enlarged expansion areas, both the source and drain regions being doped with n dopants at a concentration of 5 × 10¹⁸ cm⁻³, and the enlarged expansion area of ​​the source and drain regions having enlarged cross-sectional dimensions, thereby reducing the parasitic series resistance;and a gate underlap region located between the gate electrode and the source and drain region, wherein this underlap region is completely enclosed with a high-k dielectric spacer structure made of hafnium dioxide.