A snapback-free RC-LIGBT with separated LDMOS and LIGBT by the L-shaped SiO₂ layer

Abstract

A RC-LIGBT with separated LDMOS and LIGBT by the L-shaped SiO₂ layer is proposed and investigated. The L-shaped SiO₂ layer enhances the bulk electric field remarkably and decreases the surface electric field substantially in the breakdown state. At the forward conduction, the current is dominated by the unipolar mode (LDMOS ) before point A and bipolar mode (LIGBT) after point B, the snapback is eliminated between point A and B due to the conductivity modulation is restricted at the LIGBT region. The Free-Wheeling diode (FWD) is realized by the LDMOS region at reverse conduction state. Compared with the conventional RC-LIGBT, The proposed device shows snapback-free property and it increases the BV by 107% at the same time.