1.88-$\hbox{m}\Omega\cdot\hbox{cm}^{2}$ 1650-V Normally on 4H-SiC TI-VJFET

Abstract

The SiC trenched-and-implanted vertical junction field-effect transistor (TI-VJFET) is an excellent device for power switching applications, but its on-resistance needs to be further reduced to suppress ON-state power loss. In this paper, we used small cell pitch size and high channel/drift layer doping concentration to achieve low on-resistance. Advanced fabrication processes, such as Bosch process trench etching, self-aligned Ni silicide, and self-aligned gate overlay were implemented to support such an aggressive design. Normally on 4H-SiC TI-VJFETs of various channel-opening dimensions have been designed and fabricated based on a 12 mum, 1.8 times 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">16</sup> cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-3</sup> doped drift layer. Record high performance TI-VJFETs have been achieved and will be reported. Other SiC VJFET structures under active research are reviewed and compared to TI-VJFET. Without the need for epi-regrowth or stringent lithography alignment, TI-VJFET has the advantage of a less demanding fabrication process. In addition, its high current density, adjustable channel width and low gate resistance make TI-VJFET an excellent device for fast power switching applications.