First Demonstration of RESURF and Superjunction ß- Ga<sub>2</sub>O<sub>3</sub> MOSFETs with p-NiO/n- Ga<sub>2</sub>O<sub>3</sub> Junctions
Yibo Wang, Hehe Gong, Xiaole Jia, Genquan Han, Jiandong Ye, Yan Liu, Haodong Hu, Xin Ou, Xiaohua Ma, Yue Hao
Abstract
We for the first time demonstrate the conceptual superjunction (SJ) and reduced-surface-field (RESURF) ß- Ga <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> O <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> MOSFETs. The electric field engineering is implemented by the alternatively arranged p-NiO/n-Ga <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> O <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> lateral SJ pillars and RESURF structures in the drift region through the selective epitaxy of p-NiO. High interface quality of the NiO/ Ga <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> O <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> heterojunction is experimentally verified by a low leakage current of <10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−6</sup> A up to 1500 V without breakdown. Both SJ and RESURF ß- Ga <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> O <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> MOSFETs exhibit significantly improved breakdown voltage (V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">br</inf> ) as compared to the control devices without p-NiO. In particular, benefiting from the charge balance, the fabricated SJ-MOSFET (L <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">GD</inf> = 15.5 µm and L <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">SD</inf> = 20 µm) achieves a high V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">br</inf> of 1362 V in air, and yields a power figure-of-merit (PFOM) of 39 MW/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , which are 2.42 and 4.86 times higher than the control transistor. Our results proved that the SJ transistor utilizing p-NiO/n-Ga <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> O <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> junctions is a promising technological strategy to fulfill the potential of Ga <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> O <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> for high power applications.