A novel superjunction lateral double-diffused MOS with segmented buried P-layer

A novel superjunction (SJ) lateral double-diffused MOS (LDMOS) with charge compensation to obtain an ultralow specific on-resistance (Ron,sp) is proposed in this paper. Segmented Buried P-layer(SBP)SJ LDMOS introduces segmented buried P-layer between the drift region and the substrate. The buried layer with gradual length from the source to the drain of SBP SJ LDMOS can also optimize the charge distribution of the drift region, which means it will reduce the charge compensation for SJ layer caused by the drift region under the source and increase the charge compensation for SJ layer caused by the drift region under the drain, thus achieving charge balance in the SJ layer. Compared with the conventional(Con.) SJ LDMOS at the same drift region of 33.5 μm, the breakdown voltage (BV) of the SBP SJ LDMOS is 680.5 V, enhanced by 41.7%. In addition, P-layer can also assist in depleting drift region to increase the concentrate of drift region and to decrease the Ron,sp of the device. When the gate voltage is 15 V, the Ron,sp is 42.8 mΩ cm2, reduced by 20.5% and the figure-of-merit(FOM) is 10.8  MW cm−2, increased by 152.8%.