A Novel p-LDMOS Additionally Conducting Electrons by Control ICs

A silicon-on-insulator (SOI) p-channel lateral double-diffused MOSFET (p-LDMOS), conducting not only holes but also electrons, is proposed and investigated by TCAD simulations. Its most important advantage is the greatly improved relationship between the breakdown voltage (BV) and the specific on-resistance ( ${R} _{\mathrm{ on,sp}}$ ). The improvement is mainly attributed to two aspects. First, many holes can accumulate in the p-drift region in the on-state, which provides a low-resistance path for hole conduction. Second, a paralleled n-LDMOS is, meanwhile, automatically triggered to form a new path for electrons. Electrons have higher mobility than holes; thus, the device performance is further improved. Based on a simulation comparison with the previous p-LDMOS at the same BV of 300 V, the ${R} _{\mathrm{ on,sp}}$ of the proposed p-LDMOS decreased by 78% and the figure of merit (FOM) increased approximately 3.4 times. Moreover, the proposed device still has the conventional three-terminal style, and its fabrication process is compatible with CMOS technology.