Fabrication of 2700-V 12-$\hbox{m}\Omega \cdot \hbox{cm}^{2}$ Non Ion-Implanted 4H-SiCBJTs With Common-Emitter Current Gain of 50

Abstract

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> High-voltage blocking (2.7-kV) implantation-free SiC bipolar junction transistors with low <emphasis emphasistype="smcaps">on</emphasis>-state resistance (12 <formula formulatype="inline"><tex Notation="TeX">$\hbox{m} \Omega \cdot \hbox{cm}^{2}$</tex></formula>) and high common-emitter current gain of 50 have been fabricated. A graded-base doping was implemented to provide a low-resistive ohmic contact to the epitaxial base. This design features a fully depleted base layer close to the breakdown voltage providing an efficient epitaxial JTE without ion implantation. Eliminating all ion implantation steps in this approach is beneficial for avoiding high-temperature dopant activation annealing and for avoiding generation of lifetime-killing defects that reduce the current gain. </para>