Monolithic Integration of 1.2kV Optically-Controlled SiC npn Transistor and Antiparallel Diode

Abstract

In this letter, a 1.2kV optically-controlled SiC transistor (OCT) is proposed and fabricated. A pin diode is monolithically integrated with the SiC OCT for reverse conducting and online junction temperature measurement capability. Field limiting rings are designed as terminal structure for forward blocking capability. The test results indicated that, besides full optical control and high blocking voltage performances, the fabricated transistor chip was also capable of reverse conducting and online junction temperature measurement. The forward breakdown voltage of the transistor was about 1400V and the leakage current at 1200V was <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${2.5}\,\,\times \,\,{10}\,\,^{-{8}}\text{A}$ </tex-math></inline-formula> . The reverse turn-on voltage was about 2.6V, while the temperature sensitivity of the integrated diode was 2.99mV/K at 5mA. Under 365nm ultraviolet (UV) light with 300mW/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> incident intensity, the forward current of the OCT chip was <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$203.2\mu \text{A}$ </tex-math></inline-formula> at 0.3V, which is about <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${1.2}\,\,\times \,\,{10}\,\,^{{5}}$ </tex-math></inline-formula> times the corresponding dark current. The transient characteristic was tested at a 600V bias voltage in a resistive load circuit and the results indicate that the OCT can be switched using a 365nm UV light emitting diode.