Investigating SiC MOSFET body diode's light emission as temperature-sensitive electrical parameter

Abstract

In this paper, the light emission of SiC MOSFETs during reverse conduction, caused by the Light Emission Diode (LED)-like behaviour of the body diode, is studied and investigated. The photoemission from a 1.2 kV / 20 A commercial device has been measured experimentally using a silicon photodiode. A behavioural characterization of the light output under different junction temperatures and current values has been performed. This allows the implementation of a fast, inexpensive and non-invasive temperature sensing strategy for high-voltage SiC MOSFET chips based on the measurement of light emission during reverse conduction.

Carrier Concentration Analysis in 1.2 kV SiC Schottky Diodes Under Current Crowding

“…2c, where for voltages higher than V P I N,act =2.8 V, the slope slightly changes (see dashed lines in Fig 2c). The inset of Fig 2c also supports the JTE bipolar injection at voltage values higher than V P I N,act : at 86 A/cm 2 and 3.3 V, blue electroluminescence occurs at the end of the field plate [16], [17]. Secondly, for further analysis, a Gaussian transition between the drift and the high doped layers in a span of 5 µm is also taken into account (see Fig.…”

Online Junction Temperature and Current Simultaneous Extraction for SiC MOSFETs With Electroluminescence Effect

“…In the recent years, the electroluminescence phenomenon caused by the conduction of the SiC MOSFET body diode has been scientifically demonstrated [8][9][10][11]. Related research has shown that the luminescence intensity depends on the body diode current and the junction temperature, which paves the way for a new and promising sensing method.…”

Two Decades of Condition Monitoring Methods for Power Devices

“…The light brightness of the SiC body diode strongly depends on both the injected current magnitude and the JT. Hence, the measurement of light brightness can be used as a novel CM method for temperature detection, where only a few works have already focused on this topic [56][57][58]. The first proof of concept of the SiC light emission in a commercial power module has already proven the potentiality of this CM method [57].…”

“…Hence, the measurement of light brightness can be used as a novel CM method for temperature detection, where only a few works have already focused on this topic [56][57][58]. The first proof of concept of the SiC light emission in a commercial power module has already proven the potentiality of this CM method [57]. An inexpensive passive sensing circuit, such as a silicon photodiode and a resistor, was adopted and the photodiode output voltage was correlated to the light emission intensity as a function of the temperature.…”