High-Voltage Lateral Double-Diffused Metal-Oxide Semiconductor with Double Superjunction

Abstract

A high-voltage lateral double-diffused metal-oxide semiconductor with double superjunction (DSJ LDMOS) is proposed in this paper. A vertical SJ under the drain and a lateral SJ in the drift region are introduced to form a double SJ in the DSJ LDMOS. To suppress the substrate-assisted depletion effect of the lateral SJ, a charge compensation layer linearly doped from source to drain is adopted in the drift region. In off-state, the vertical SJ enhances the depletion of the substrate to improve the vertical breakdown voltage (BV) and modulates the lateral electric field to increase the lateral BV. The lateral SJ increases the lateral BV and modulates the vertical electric field to improve the vertical BV. The vertical SJ is composed of N and P pillars with different concentrations. In on-state, the lateral SJ also provides a low-resistance channel, which decreases the specific on-resistance (R_on,sp). Simulation results indicate that the BV, figure of merit (FOM), and R_on,sp of the DSJ LDMOS are 1138 V, 10.5 MW cm⁻², and 103.4 mΩ cm², respectively. The BV and FOM of the DSJ LDMOS are increased by 31.3% and 483% compared with the conventional vertical SJ LDMOS (Con. VSJ LDMOS), while the R_on,sp of the DSJ LDMOS is reduced by 70%. The “silicon limit” is thus broken by the DSJ LDMOS.