The present disclosure provides a semiconductor device and a manufacturing method therefor. The manufacturing method for a semiconductor device is provided for forming through-holes in a semiconductor device, comprising: forming a plurality of shallow trench isolations in portions of a substrate corresponding to memory cell regions; forming a plurality of gates on surfaces of the portions of the substrate; forming spacers on side walls at both sides of the gates extending in the first direction; depositing a sacrificial layer on the memory cell region; removing portions of the sacrificial layer corresponding to the shallow trench isolations at memory cell drain, and depositing an isolation dielectric on the shallow trench isolations at the memory cell drain to form isolation strips; and removing the remaining sacrificial layer to form bottom through-holes in spaces formed after removing the remaining sacrificial layer.