A novel p-channel SOI LDMOS transistor with tapered field oxides

The on-resistance of p-channel RESURF (reduced surface field) LDMOS (lateral double-diffused MOS) transistors has been improved by using a new tapered TEOS field oxide on the drift region of the devices. With a similar breakdown voltage, at V/sub gs/=-5.0 V, the specific on-resistance of the LDMOS with the tapered field oxide is about 31.5 m/spl Omega//spl middot/cm/sup 2/, while that of the LDMOS with the conventional field oxide is about R/sub sp/=55.3 m/spl Omega//spl middot/cm/sup 2/.