Breakdown voltage improvement of LDMOSs by charge balancing: An inserted P-layer in trench oxide (IPT-LDMOS)

For the first time, the novel inserted P-layer in trench oxide of LDMOS structure (IPT-LDMOS) is proposed in which a trench oxide with inserted P-layer is considered in the drift region to improve the breakdown voltage. Our simulation with two dimensional ALTAS simulator shows that by determining the optimum doping concentration of the P-layer, the charges of the N-drift and P-layer regions would be balanced. Therefore, complete depletion at the breakdown voltage in the drift region happens. Also, electric field in the IPT-LDMOS is modified by producing additional peaks which decrease the common peaks near the drain and source junctions.

► Novel inserted P-layer in trench oxide of LDMOS structure is proposed.
► A trench oxide with inserted P-layer in drift region improves breakdown voltage.
► Charges of N-drift and P-layer regions can be balanced in optimum doping of P-layer.
► Complete depletion in the drift region at breakdown voltage of structure happens.
► Electric field in the structure is modified by producing additional peaks.