Abstract
An improved 4H-SiC trench MOS barrier Schottky (TMBS) structure that can significantly reduce the specific on-resistance ( $R_{on,sp}$ ) is proposed in this paper. Compared with the conventional TMBS structure, an N-type region is added around the P+ shielding region and along the trench sidewall in the proposed structure, and the doping concentration is higher than that of the drift region. The JFET resistance, and spread resistance can both be reduced significantly during the forward bias to produce a much lower $R_{on,sp}$ , which have been verified through the numeric simulations and modeling analysis. The critical parameters (N-type region width and its doping concentration) of the proposed structure are mainly optimized by the ATLAS simulation tool. As a result, the breakdown voltage and leakage current of the improved structure remain basically unchanged compared with the conventional TMBS. However, the $R_{on,sp}$ and FoM ( BV 2/ $R_{on,sp}$ ) can be effectively improved by 41.9% and 70.9%, respectively.
Highlights
Silicon carbide (SiC) has many excellent characteristics that makes it suitable for high temperature, high voltage, and high power applications [1], [2]
As the junction depth of P+ region is limited by ion implantation energy, there is a tradeoff between on-resistance (Ron) and breakdown voltage (BV) in junction barrier Schottky (JBS) devices
The basic physical models used in simulations include the Fermi–Dirac statistics and bandgap narrowing models which account for the carrier statistic
Summary
Silicon carbide (SiC) has many excellent characteristics that makes it suitable for high temperature, high voltage, and high power applications [1], [2]. Compared with Si-based PiN diode, 4H-SiC Schottky barrier diode (SBD) has a relatively simple manufacturing process and behaves lower conduction voltage and faster switching speed [3], [4]. Its reverse leakage current degenerates rapidly when Schottky surface electric field is high enough that a tunneling effect occurs [5]. In order to avoid tunneling current and maintain low conduction voltage, junction barrier Schottky (JBS) diode is proposed [6], [7]. As the junction depth of P+ region is limited by ion implantation energy, there is a tradeoff between on-resistance (Ron) and breakdown voltage (BV) in JBS devices. The trench JBS (TJBS) devices have solved this problem effectively by making a larger design window that enables good reverse blocking and forward conduction capabilities at the same time [8]–[10]. The 4H-SiC TMBS devices are of interest because they don’t need costly
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
