5kV SiC Lateral RESURF MOSFET Charge-Modulated by Multiple P-Islands with Ohmic Contacts for Improved Dynamic Performance

In this work, a novel silicon carbide lateral MOSFET (SiC LMOS) structure with ohmic contact on multiple P-islands is proposed to resolve the dynamic problem in multiple P-islands structure. In the conventional structure, although the introduction of multiple P-islands can increase the breakdown voltage (BV), the dynamic specific on-resistance <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(R_{\text{on},\text{sp}})$</tex> is increased to an enormously large value due to the unrecoverable depletion of multiple P-islands after blocking state. This work addresses this issue with the proposed structure and validated with numerical simulation. The static simulation curves indicate the static characteristic including BV and Ron, sp of the proposed device is close to that of the conventional structure. On the other hand, the dynamic simulations including gate charge simulation and double pulse simulation, show that compared with the conventional device, the gate charge FOM <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(R_{\text{on},\text{sp}}\times Q_{\text{GD}})$</tex> is largely reduced and the dynamic <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$R_{\text{on},\text{sp}}$</tex> of the proposed device is significantly reduced by several magnitude from <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$3.21\times 105\ \mathrm{m}\Omega\cdot \text{cm}^{2}$</tex> to 265.6 m <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\Omega\cdot \text{cm}^{2}$</tex> which equals its static <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$R_{\text{on},\text{sp}}$</tex>. In addition, the switching loss is reduced by 70.5%. The mechanism for the improved performance is discussed in detail with carrier transport analysis.