Packaged $\beta$-Ga<sub>2</sub>O<sub>3</sub> Trench MOS Schottky Diode With Nearly Ideal Junction Properties
Florian Wilhelmi, Shinji Kunori, Kohei Sasaki, Akito Kuramata, Y. Komatsu, Andreas Lindemann
Abstract
Recently, gallium oxide (Ga <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> O <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$_3$</tex-math></inline-formula> ) has attracted great interest as a material for efficient power devices. Yet, experimental studies rather concentrate on the investigation of bare dies and lack the analysis of devices in industry-standard packages. Furthermore, while Ga <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> O <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$_3$</tex-math></inline-formula> trench MOS Schottky barrier diodes (SBDs) appear to be promising candidates, temperature-dependent measurements previously revealed inhomogeneous junctions. In this letter, a 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> -Ga <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> O <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$_3$</tex-math></inline-formula> trench MOS SBD is presented. The diode exhibits a homogeneous Schottky junction and nearly ideal thermionic current flow. This indicates better junction properties than previously observed for trench as well as non-trench Ga <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> O <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$_3$</tex-math></inline-formula> SBDs, with only a slight influence of interface states at high temperatures. As a next step toward application, the chip is successfully bonded in an industry-standard TO-247 package. The molded discrete is operational at low temperatures of −50 °C and up to high temperatures of 150 °C while exhibiting a lower increase in <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</small> -resistance with rising temperature than SiC Schottky diodes.