Semiconductor device and manufacturing method thereof

A manufacturing method of a semiconductor device, comprising steps of:

• depositing an N-drift layer on a termination area of a substrate;
• conducting an ion implant process on the N-drift layer to form a plurality of P-type pillars;
• depositing a N-type epitaxial layer on the P-type pillars;
• conducting an ion implant process on the N-type epitaxial layer to form a first P-type epitaxial layer and at least one localized P region at a front side of the termination area;
• conducting a field oxidation to the first P-type epitaxial layer to form a second P-type epitaxial layer, the field oxidation spreads from the first P-type epitaxial layer to the end of the P-type pillars to form the second P-type epitaxial layer;
• and
• forming a field oxide layer on the first P-type epitaxial layer, the localized P region and the N-type epitaxial layer;
• wherein the localized P region passes though the N-type epitaxial layer to the field oxide layer, the field oxide layer electrically connects to the second P-type epitaxial layer by the localized P region;
• conducting a polysilicon deposition on the first P-type epitaxial layer to form a polysilicon layer at the front side of the termination area, wherein the polysilicon layer abuts against the field oxide;
• disposing a source electrode on a side of the polysilicon layer and the first P-type epitaxial layer, wherein the first P-type epitaxial layer extends from the source electrode;
• disposing a gate electrode disposed on another side of the polysilicon layer.