SEMICONDUCTOR DEVICE AND MANUFACTURING METHOD THEREFOR

摘要

Provided is a semiconductor device in which a voltage does not need to be applied to an element-isolating region that self-aligns with word lines (WL). This method for manufacturing said semiconductor device has the following steps: a step in which provisional active regions that are shaped such that active regions (3a) that are adjacent in an X direction are connected to each other are formed; a step in which a sacrificial film is formed; a step in which etching is performed, including the sacrificial film, so as to form a plurality of first trenches that separate the active regions (3a); a step in which element-isolating insulating films (10) are embedded in the first trenches and the sacrificial film is then removed; a step in which first side-wall insulating films that cover the exposed side surfaces of the element-isolating insulating films (10) and second side-wall insulating films that cover the side surfaces of the first side-wall insulating films are formed; a step in which cap insulating films are embedded in second trenches that appear due to the formation of the second side-wall insulating films; and a step in which a plurality of third trenches are formed at the positions of the second side-wall insulating films and word lines (WL) are formed thereunder.