Beyond the boundaries of state-of-the-art power semiconductor devices - an invitation to venture on uncharted territories -
D.G. Sdrulla1,2, G. Brezeanu1, G. Pristavu1, F. Draghici1, R. Pascu13 1 University “Politehnica” of Bucharest, Romania; 2 Analog Power Conversion LLC; 3 National Institute for R&D in Microtechnology - IMT Bucharest, Romania
The paper presents current capabilities of Semiconductor Power Devices and expands on promising emerging solutions for extending the operating frequency ranges and increasing switching energy efficiency. Following a trend is normal in any field, and the semiconductor industry is not an exception. Let's take the case of Silicon Carbide (SiC) MOSFETs, aimed to displace Silicon (Si) IGBTs in every application. The IGBT is a slow switching power device. Since the SiC MOSFET does not exhibit this drawback, the focus is on racing to lower the Specific ON resistance. The paper will initially discuss SiC MOSFETs developed and manufactured for operating frequencies over 50 MHz. What seemed to be an impossible task is now a reality and unique aspects towards reaching this milestone will be shared. Silicon IGBTs are the work horse of the power industry, due to their very high current capability. In order to increase their speed and switching efficiency, the emerging concept of "forced extraction" of carriers from the drift region, will be presented in this work. The challenge is contacting this region without affecting its blocking capability, and using an Extraction Device, that can be integrated into the Free Wheeling Diode, which is mandatory in any high-power application. Exciting new things for any engineer with passion and desire to excel. Finally, novel concepts using SiC JFETs will be introduced. Simple and reliable, this device is once again getting significant attention, mainly for use in solid state circuit breaker applications. Leading companies are using JFETs together with a low voltage Silicon MOSFET in a cascode configuration, which enables the conversion of the ensemble from a Normally ON to a Normally OFF power switch.