Trench mosfet structure and manufacturing method thereof

A manufacturing method of a trench MOSFET structure, comprising steps:

• S100:
• taking an N+ substrate, and sequentially epitaxially growing an N- drift region and a P-type base region on the N+ substrate;
• wherein the N+ substrate is N-type heavily doped, the N- drift region is N-type lightly doped, and the P-type base region is P-type doped;
• S200:
• forming an N+ source region by performing ion implantation on an upper portion of the P-type base region;
• wherein the N+ source region is N-type heavily doped;
• S300:
• manufacturing a trench gate structure and an N-type region;
• wherein the trench gate structure penetrates the N+ source region from a middle portion of the N+ source region and extends into the P-type base region, a bottom portion of the trench gate structure is connected to the N- drift region through the N-type region, and the N-type region is N-type doped;
• S400:
• forming P + regions on two sides of the N+ source region by performing ion implantation, and performing high-temperature annealing treatment;
• wherein the P+ region is P-type heavily doped;
• S500:
• manufacturing an interlayer dielectric layer on an upper end of the trench gate structure;
• wherein portions of the N+ region on two sides of the trench form platform regions, and two ends of the interlayer dielectric layer respectively extend horizontally and are respectively disposed on the platform regions;
• and
• S600:
• manufacturing a source metal at an upper end of the interlayer dielectric layer and an upper end of the P-type base region, and manufacturing a drain metal at a lower end of the N+ substrate.