Semiconductor device and manufacturing method thereof

A manufacturing method of a semiconductor device, comprising:

• forming a bottom insulating layer on a substrate;
• forming two stacked structures on the bottom insulating layer, wherein each of the stacked structures includes a plurality of gate layers, a plurality of gate insulating layers, a top insulating layer and a conductive mask layer, the gate layers and the gate insulating layers are alternately disposed on the bottom insulating layer, the top insulating layer is disposed on the gate layers and the gate insulating layers, and the conductive mask layer is disposed on the top insulating layer;
• forming a charge trapping structure and a channel layer on a lateral surface of each of the stacked structures and a top surface of the bottom insulating layer, wherein each of the charge trapping structures includes a plurality of first dielectric layers and a plurality of second dielectric layers;
• etching part of each of first dielectric layers to expose part of each of the second dielectric layers;
• etching part of each of second dielectric layers to expose part of the channel layer;
• and
• forming a landing pad layer on the conductive mask layer, the first dielectric layers and the second dielectric layers to connect the conductive mask layer and the channel layer.