Lateral power MOSFETs with drift trench electrodes and drain trench electrodes for a 42 V automotive system

A novel lateral power metal-oxide-semiconductor field-effect transistor (MOSFET) with two kinds of trench electrodes for a 42 V automotive system is presented. The trench electrodes are named a ‘drift trench electrode’ and a ‘drain trench electrode’. It is shown that this MOSFET exhibits a breakdown voltage of 81 V and a specific on-resistance of 67 mΩ·mm2, by a simulation study. Compared with an 80 V-class conventional MOSFET, the specific on-resistance is reduced by 64%. The drift trench electrode works for the reduced surface field (RESURF) action in the off-state in addition to lowering the resistance of the drift region owing to the accumulation layer in the on-state. Alternatively, the drain trench electrode works by spreading the current distribution in the on-state, allowing lower specific on-resistance. Moreover, the conduction loss, the switching loss, and the gate driving loss of the proposed MOSFET were estimated.