A 2055-V (at 0.7 $\hbox{mA/cm}^{2}$) 24-A (at 706 $\hbox{W/cm}^{2}$) Normally On 4H-SiC JFET With 6.8- $\hbox{mm}^{2}$ Active Area and Blocking-Voltage Capability Reaching the Material Limit

Abstract

A normally on 4H-SiC vertical-junction field-effect transistor (VJFET) of 6.8-mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> active area was manufactured in seven photolithographic levels with no epitaxial regrowth and a single masked ion-implantation event. The VJFET exhibits low leakage currents with very sharp onsets of voltage breakdowns. At a forward gate bias of 2.5 V, the VJFET outputs 24 A (353 A/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ) at a forward drain-voltage drop of 2 V (706 W/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ), with a current gain of I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">D</sub> /I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">G</sub> = 21818, and a specific ON-state resistance of 5.7 mOmegaldrcm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . Self-aligned floating guard rings provide edge termination that blocks 2055 V at a gate bias of -37 V and a drain-current density of 0.7 mA/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . This blocking voltage corresponds to 94.4% of the VJFET's 11.7-mum/3.46 times 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">15</sup> -cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> SiC drift layer limit and is the highest reported blocking-voltage efficiency of any SiC power device under similar drain-current-density conditions.