Mosfet device and manufacturing method therefor

A manufacturing method for a metal oxide semiconductor field effect transistor (MOSFET) device, comprising:

• providing a substrate, forming a patterned mask layer on the substrate, and implanting first ions of a first conductivity type into a surface layer of the substrate by using the patterned mask layer as a mask, to form a well region;
• forming spacers on both sidewalls of the patterned mask layer, and implanting ions of a second conductivity type into a surface layer of the well region by using the patterned mask layer and the spacers as a mask, to form a source region;
• implanting second ions of the first conductivity type into the substrate below the well region by using the patterned mask layer and the spacers as a mask, wherein the second ions are easier to diffuse in the substrate than the first ions, to form a semi-superjunction connected to a bottom of the well region and self-aligned with the source region;
• and
• forming, on the substrate, a gate oxide layer and a gate that are sequentially stacked, wherein a region in which the well region overlaps the gate is used as a channel of the MOSFET device.