Trench mosfet and manufacturing method of the same

A trench MOSFET, comprising:

• a substrate;
• an epitaxial layer having a first conductivity type formed on the substrate, and the epitaxial layer has a trench;
• a gate located in the trench;
• a gate oxide layer located between the gate and the trench;
• a source region having the first conductivity type located on a surface of the epitaxial layer on two sides of the trench;
• a body region having a second conductivity type located in a portion of the epitaxial layer below the source region;
• and
• an anti-punch through region having the second conductivity type located at an interface of the body region and the source region, wherein a doping concentration of the anti-punch through region is higher than a doping concentration of the body region,
• wherein the epitaxial layer has a first pn junction near the source region and a second pn junction near the substrate, and N regions are divided into N equal portions between the first pn junction and the second pn junction, and N is an integer greater than 1,
• wherein the closer the N regions are to the first pn junction, the greater a doping concentration thereof is, and
• wherein each of the N regions has an integrated area of doping concentration, and the closer the N regions are to the first pn junction, the greater the integrated area of doping concentration thereof is.