Demonstration of Picosecond 4H-SiC Diode Avalanche Shaper With Voltage Rise Rate of 11.14 kV/ns and Peak Power Density of 62 MW/cm$^2$

Abstract

In this letter, for the first time, a high-performance picosecond 4H-SiC diode avalanche shaper (DAS) with a novel <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">${p^+/p^-/n^+}$</tex-math></inline-formula> multilayer epitaxial structure is experimentally demonstrated and characterized. For fabrication of our 4H-SiC DAS, the multilayer epitaxial stacks have been designed in detail and grown using continuous multilayer epitaxial wafer growth. To excite the delayed avalanche breakdown (DAB) effect, the electric field profile in multilayer epitaxial stacks has been numerically simulated in detail to suppress the surface electric field crowding and premature breakdown during the overvoltage pulse applied. A 2.5-kV, 1-ns pulsed power generator is adopted to drive our fabricated SiC DAS, the output on a 50 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\Omega$</tex-math></inline-formula> load is 1860 V, 100 ps, lead a voltage rise rate of 11.14 kV/ns, and a peak power density of 62 MW/cm <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^2$</tex-math></inline-formula> . Furthermore, the fabricated SiC DAS operates stably in multipulse mode at 1 MHz. To the best of our knowledge, this is the first experimental result reported for picosecond DAS based on the 4H-SiC. This article is significant for developing 4H-SiC-based ultrafast closing switches.