First Experimental Demonstration of TiN_<i>x</i>O_<i>y</i> Resistive Field Plate on p-GaN HEMTs With Simultaneously Enhanced <i>BV</i> and R_on

This work demonstrates p-GaN high electron mobility transistors (HEMTs) with the resistive field plate (RFP) for simultaneously improved ON-state and OFF-state performance. The RFP-HEMT features a high-resistivity titanium oxynitride (TiN<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><i>x</i></sub>O<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><i>y</i></sub>) resistive passivation layer extending from the source toward the drain. Owing to the surface electric field (<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">E</i>-field) modulation effect and the 2-D electron gas (2-DEG) enhancement effect, the designed RFP-HEMTs not only realize higher breakdown voltage (<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">BV</i>) in the blocking state, but also achieve lower ON-state resistance (<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">R</i><sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><roman>on</roman></sub>) in the conductive state. Compared with the conventional insulator passivated devices, the optimized RFP-HEMTs with the gate-to-drain distance of 20 μm realize the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">BV</i> of 1860 V improved by 111.36%, the specific ON-state resistance (<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">R</i><sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><roman>on</roman>,<roman>sp</roman></sub>) of 5.78 ± 0.34 mΩ⋅cm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><roman>2</roman></sup> decreased by 25.03%, and the Baliga figure of merit (BFOM) of 599 MW/cm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><roman>2</roman></sup> improved by 496%. Furthermore, the RFP-HEMTs exhibit an optimized dynamic/static ON-state resistance ratio, which can be attributed to the effective surface <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">E</i>-field modulation and the surface state filling. The results prove that the TiN<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><i>x</i></sub>O<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><i>y</i></sub> RFP technology offers a simple and efficacious approach to improve the device performance without the limit of <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">BV</i>-<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">R</i><sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><roman>on</roman></sub> trade-off in conventional p-GaN gate HEMT design.