A high density, low on-resistance p-channel trench lateral power MOSFET for high side switches

A trench lateral power MOSFET (TLPM) has a unique structure. The gate is formed on the trench sidewall, and the drain is connected with metal wire at the bottom of the trench. This structure enables high device density compared to conventional lateral DMOSs. A p-channel TLPM for high side switches has been first integrated. A specific on-resistance of 28 m/spl Omega/ - mm/sup 2/ with a breakdown voltage of 35 V has been realized. This is the best specific on-resistance in this voltage class for a p-channel lateral power MOSFET embedded with logic devices. P-channel, n-channel TLPM devices and a 0.6 /spl mu/m bi-CMOS are fabricated on the same silicon wafer, thus a synchronous switching converter can be implemented on a single chip.