The invention discloses an
LDMOS (Laterally Diffused
Metal Oxide Semiconductor) device and a manufacturing method thereof, and the device comprises an SOI (
Silicon On Insulator) substrate which comprises a
silicon substrate and an insulating layer formed in the
silicon substrate, and the insulating layer isolates the
silicon substrate into a top substrate located at the upper part and a bottom substrate located at the lower part; the
gate dielectric layer is formed on the top layer substrate; the grid
electrode is formed on the grid
dielectric layer; wherein a well region and a drift region are formed in the top substrate, a first heavily doped region is formed in the drift region, a second heavily doped region is formed in the well region, an LDD region is formed in the well region between the second heavily doped region and the gate in the transverse direction, and the LDD region is in contact with the second heavily doped region; when the
LDMOS device works, the first heavily doped region is a drain
electrode, the LDD region is a source
electrode, and the second heavily doped region is a body electrode. According to the
LDMOS device provided by the embodiment of the invention, the
floating body effect can be improved, and the design flexibility of an SOI
chip is improved.