Semiconductor device and manufacturing method of semiconductor device

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

• forming supports penetrating a well structure, the supports protruding upward from the well structure;
• forming a stack structure on the supports, the stack structure penetrated by holes and having an etch stop pattern disposed on a portion of a bottom surface of the stack structure facing the well structure;
• forming a multi-layered memory layer on a surface of an opening region including a horizontal space opened between the well structure and the stack structure and the holes;
• forming a channel layer on a surface on the multi-layered memory layer;
• forming a gap fill insulating layer on the channel layer, the gap fill insulating layer filling the opening region;
• forming a slit penetrating the etch stop pattern from the stack structure, the slit separating the etch stop pattern into source gate patterns;
• forming a protective layer on a sidewall of the slit;
• forming a first trench penetrating the multi-layered memory layer and the channel layer not blocked by the protective layer, the first trench extending to the inside of the gap fill insulating layer;
• forming a doped semiconductor pattern extending from the inside of the first trench to between the source gate patterns;
• and
• forming a protective pattern exposing a first part of the doped semiconductor pattern by etching the protective layer.