Investigation of <i>β</i>-Ga₂O₃ MOSFET With Double Drift Layers by TCAD Simulation

Abstract

In this article, we have proposed and analyzed a novel <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula> -phase gallium oxide ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula> -Ga2O3) metal–oxide–semiconductor field-effect transistor (MOSFET) with double drift layers (DDLs) located in the gate to drain region. This device has a highly doped drift (HDD) layer that is positioned below a lowly doped drift layer, which are connected in parallel. The HDD is located at a distance ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${d}$ </tex-math></inline-formula> ) from the gate metal to ensure optimal breakdown performance. We extensively investigated how the doping concentration and thickness of the HDD, with both small and large <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${d}$ </tex-math></inline-formula> values, affect the device’s electrical characteristics. Our simulations revealed that the proposed device achieved a decent power figure-of-merit (PFOM) of 582.0 and 461.2 MW/cm2 at <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${d}$ </tex-math></inline-formula> values of 0.5 and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$3.5~\mu \text{m}$ </tex-math></inline-formula> , respectively. Compared to the control device with single drift layer, the designed construction achieved an excellent PFOM and reduced specific ON-resistance ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${R} _{{\text {on},\text {sp}}}$ </tex-math></inline-formula> ), while maintaining an unaltered or appreciable breakdown voltage ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V} _{{\text {br}}}$ </tex-math></inline-formula> ). This proposed structure provides a new way to achieve high performance for <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula> -Ga2O3 MOSFETs.