Development of a High-Performance 3,300V Silicon Carbide MOSFET

Abstract

To address stringent performance and reliability requirements of industrial and traction power conversion systems we have developed planar 3,300V MOSFETs at a 6-inch SiC-compatible silicon CMOS foundry. By optimizing the unit cell structure and using a deep current-spreading layer we demonstrated a low MOSFET specific on-resistance RDSA=11.2 mΩ·cm2(ID=5A, VGS=15V) and fast switching for the baseline design. Robust short-circuit handling (7.5μs at Vds=1500V and 5.0μs at Vds=2200V) was demonstrated with an alternative unit cell design with RDSA=14.8 mΩ·cm2(ID=5A, VGS=15V).

Characterization of 4.5 kV Charge-Balanced SiC MOSFETs

“…At low frequencies, the volume and weight of passive components, such as filters and transformers, limit design flexibility and increase fabrication and installation costs for MV systems. Unipolar Si devices (e.g., MOSFET) have faster switching speeds than their bipolar Si counterparts, but their high conduction losses make them less suitable for MV applications than Si IGBTs [2][3][4].…”

“…Unipolar silicon carbide (SiC) devices can achieve lower on-resistance at higher voltages than unipolar Si devices thanks to the higher breakdown electric field strength and wider bandgap of the material. However, at MV (greater than 3.3 kV), it is still difficult for SiC unipolar devices (e.g., MOSFET) to compete with the low conduction losses of Si bipolar devices (e.g., IGBT) [2][3][4]. Accordingly, researchers have explored super-junction (SJ) structures to break this 1-D SiC limit (Fig.…”