The present disclosure provides a method of manufacturing a semiconductor device. The method includes steps of creating at least one trench in a substrate; depositing a conductive material to partially fill the trench; and forming an insulative piece in the trench and extending into the conductive material.

A method of manufacturing a semiconductor device is provided. The method includes: providing a substrate; forming a metallization layer on the substrate; forming a first sacrificial layer and a second sacrificial layer; forming a first mask layer and a second mask layer, wherein the first mask layer covers the first sacrificial layer, the second mask layer covers the second sacrificial layer; forming a first width controlling element on a lateral surface of the first mask layer and a second width controlling element on a lateral surface of the second mask layer; removing the first mask layer and the second mask layer; and patterning the metallization layer to form a first word line between the first sacrificial layer and the second sacrificial layer, wherein a dimension of the first word line depends on a dimension of the first width controlling element.