Tailoring the Interface between Dielectric and 4H-SiC by Ion Implantation

Abstract

Abstract. In this paper, the effect of carbon (C), silicon (Si) and nitrogen (N) implantation on the interface properties of 4H-SiC/SiO 2 and the implications for 4H-SiC bipolar junction transistors (BJT) passivation are discussed. 4H-SiC epi-layer have been implanted with 12 C, 14 N and 28 Si ion at three different doses with energies of 3, 3.5 and 6 keV, respectively, resulting in a projected range of 8 nm for the three ions. Then metal oxide semiconductor (MOS) structures with SiO 2 as dielectric have been fabricated. Capacitance voltage measurements show an increase in the negative fixed charges for all the implanted samples as a function of implantation induced damage. Similarly, in the case of C and Si, the surface roughness increases as a function of dose and the mass of the ions. No reduction of D it s due to the implantations is seen for any of the ions. Furthermore, TCAD device simulations of npn bipolar junction transistors (BJT), using the interface and fixed charges extracted from CV measurements, show a way to further optimize current gain and breakdown properties for the BJT.