New concept for improving characteristics of high-voltage power devices by buried layers modulation effect

A new concept is proposed for improving characteristics of the power devices by P-type and I-type buried layers, in which the P-type buried layer is implanted into the P-substrate by silicon window underneath the source. The mechanism of breakdown is that the additional electric fields produced by P-type buried layer charges and different I-type buried layer modulate surface electric field, which decreases drastically the electric field peaks near the drain contact and P-base/n-drift junctions. Moreover, the specific on-resistance is decreased as a result of increasing the drift region doping and self-heating effect is alleviated due to the silicon window and P-type buried layer compared with the conventional SOI and PSOI