Trench Semiconductor Structure and Manufacturing Method Thereof

A trench semiconductor structure, comprising:

• a semiconductor material layer of a first conductivity type, having a first region and a second region surrounding the first region;
• a first trench structure, recessed from a first surface of the semiconductor material layer into the semiconductor material layer, and comprising a first electrode, a first gate, and a first oxide layer surrounding and separating the first electrode and the first gate, wherein the first electrode includes a first portion and a second portion connected to the first portion, the first portion being adjacent to the first gate, and the second portion overlapping with the first portion and the first gate in a top view of the trench semiconductor structure;
• a second trench structure, recessed from the first surface of the semiconductor material layer into the semiconductor material layer, and comprising a second electrode, a second gate and a second oxide layer surrounding and separating the second electrode and the second gate;
• and
• a first doped region of a second conductivity type, disposed in the semiconductor material layer, and between the first trench structure and the second trench structure;
• and
• wherein the first electrode and the second electrode are disposed between the first gate and the second gate,
• a portion of the first electrode, a portion of the second electrode, and the first doped region are located in the first region, and
• the first gate and the second gate are located in the second region.

A method of manufacturing a trench semiconductor structure, comprising:

• forming a first trench in a semiconductor material layer of a first conductivity type, wherein the first trench extends from a first surface of the semiconductor material layer towards a second surface of the semiconductor material layer opposite to the first surface;
• forming a first electrode in the first trench, wherein the first electrode comprises a first portion, and a second portion located below the first portion and connected to the first portion;
• forming a first gate in the first trench, wherein the first gate is adjacent to the first portion of the first electrode and above the second portion of the first electrode, and the first electrode and the first gate form a first trench structure;
• forming a first doped region of a second conductivity type in the semiconductor material layer adjacent to the first surface, wherein the first portion of the first electrode is located between the first doped region and the first gate;
• forming an interlayer dielectric layer on the first surface of the semiconductor material layer, wherein the interlayer dielectric layer covers the first trench structure and the first doped region;
• forming a groove extending through the interlayer dielectric layer, the first groove exposing the first doped region and the first portion of the first electrode;
• forming a shielding metal layer in the groove and on the interlayer dielectric layer, wherein the shielding metal layer covers the interlayer dielectric layer and the first doped region;
• and
• forming a metal layer in the groove and on the shielding metal layer,
• wherein the first portion of the first electrode and the first doped region are in contact with the shielding metal layer and electrically connected to the metal layer.