Diamond-on-Si IGBT With Ultrahigh Breakdown Voltage and On-State Current

Diamond-on-Si insulated gate bipolar transistors (IGBTs) on a floating zone (FZ) silicon wafer is fabricated and investigated. The polycrystalline diamond (PCD) of the Diamond-on-Si IGBT is used for a heat spreader of high-power devices, which helps to raise the breakdown voltage and short time at the on-state so as to cool down temperature in the N-drift region in IGBT operating and reduce the turn-off power. Moreover, the Diamond-on-Si IGBT could improve more current extremely, and nano diamond particles (NDs) grain size near the interface Si/Diamond that led to a higher in-plane thermal dissipation compared with the conventional IGBT. By fine control of the seed size and areal density, thermal conductivity near multihole collector contacts region can therefore be improved. Measurement results of diamond of $140~\mu $ m IGBT show that under turn-off loss ( ${E}_{\text {off}}$ ) of 1.24 mJ/cm ² , breakdown voltage ( ${V}_{\text {BR}}$ ) of 1.32 kV and collector-emitter current ( ${I}_{\text {ce}}$ ) is as high as 150 A/cm ² , which is superior to most of conventional IGBTs. In addition, the reasons for the Diamond-on-Si IGBTs results are also discussed in this article. Finally, the advantages of Diamond-on-Si IGBTs in terms of thermal performances are verified by measurement, and this article also provides a guideline for the process of Diamond IGBTs by the liquid Ga catalysis.