Contact structure of semiconductor device and manufacturing method therefor

A manufacturing method for manufacturing a contact structure of a semiconductor device, wherein the semiconductor device comprises an epitaxial layer and a doped region located in the epitaxial layer, and the manufacturing method comprises:

• forming an interlayer dielectric layer on the epitaxial layer;
• forming a contact hole, wherein the contact hole comprises a first portion extending through the interlayer dielectric layer and a second portion extending into the doped region, a size of the first portion is greater than a size of the second portion, the second portion is open on a bottom surface of the first portion, and a bottom surface of the second portion is arranged in the doped region;
• forming a contact layer, wherein the contact layer comprises a first contact layer arranged on the bottom surface of the first portion and a second contact layer arranged on the bottom surface of the second portion;
• and
• forming a conductive channel filling the contact hole and contacting the contact layer.