E-Mode Vertical <i>β</i>-Ga<sub>2</sub>O<sub>3</sub> (010) U-Trench MOSFETs With In-Situ Mg-Doped Current Blocking Layers
Sudipto Saha, Walid Amir, Jiawei Liu, Lingyu Meng, Dongsu Yu, Hongping Zhao, Uttam Singisetti
Abstract
This work presents the fabrication and performance analysis of a novel enhancement-mode (E-mode) vertical <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 (010) U-trench MOSFET featuring an in-situ Mg-doped current blocking layer (CBL) for high-power applications. Utilizing metal-organic chemical vapor deposition (MOCVD), we achieved precise Mg doping of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1.3\times 10^{{19}}$ </tex-math></inline-formula> cm<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${}^{{a}-{3}}$ </tex-math></inline-formula> within the CBL to enhance current blocking capability while maintaining a robust threshold voltage of 5 V and a low on-state resistance of 5 m<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\Omega $ </tex-math></inline-formula>.cm2. The device achieved an on-current of 1.56 kA/cm2 at V<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${}_{\textit {GS}} =20$ </tex-math></inline-formula> V and V<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${}_{\textit {DS}} =40$ </tex-math></inline-formula> V. The fabricated devices demonstrate a peak breakdown voltage of 101 V with an average breakdown field strength of up to 1.68 MV.cm<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${}^{-{1}}$ </tex-math></inline-formula>. The calculated power device Figure of Merit is 2 MW.cm<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${}^{-{2}}$ </tex-math></inline-formula>.