4.5 kV novel high voltage high performance SiC-FET “SIAFET”

A novel high voltage SiC MOS device named SIAFET (Static induction Injected Accumulated FET) is proposed, which has no pn junction in its on-current flow path and has a conductivity modulation by carriers injected from a p+ buried gate. SIAFET with blocking voltage (BV) of 5500 V and specific on-resistance RonS (without the conductivity modulation) of 57 mΩcm² was designed by using the 6200 V mesa JTE and was fabricated using 4H-SiC substrates. Its basic operation has been confirmed for the first time and it has been demonstrated that its RonS has been shown to reduce to less than 1/6 by SIAFET action. Although its achieved BV is relatively low (2030 V and 4580 V) and its RonS is relatively high (172 mΩcm² and 387 mΩcm²), RonS of 4580 V SiC-SIAFET is less than 1/25 that of the theoretical RonS limit of Si-MOSFET for this BV