A VDMOS (Vertical Double-
Diffusion Metal-
Oxide-
Semiconductor) device with a non-uniform
floating island structure belongs to the technical field of
semiconductor power. For the VDMOS device, the non-uniform
floating island structure is drawn into a first conductive type
semiconductor drift region of a common VDMOS and comprises at least two
layers of second conductive type
semiconductor floating islands which are respectively an upper layer of second conductive type semiconductor
floating island and a lower layer of second conductive type semiconductor floating island, wherein the upper layer of second conductive type semiconductor floating island is larger in transverse width dimension and lower in
doping density, and the lower layer of second conductive type semiconductor floating island is smaller in transverse width dimension and higher in
doping density. Compared with the common VDMOS, the VDMOS with the non-uniform floating island, provided by the invention, can adopt higher electrical resistivity of an epitaxial layer under the condition the same puncture
voltage, thereby the on-resistance is greatly reduced; compared with a VDMOS with a uniform floating island, the VDMOS with the non-uniform floating island is wider in current path and also can lead the on-resistance to be reduced; and compared with a super-junction VDMOS, the VDMOS is better in the
reverse recovery characteristic of a body
diode and is relatively simple in process.