Methods of manufacturing a semiconductor device and a semiconductor memory device thereby

Abstract

A method of manufacturing a semiconductor device comprises forming memory cells on a memory cell region, alternately forming a sacrificial layer and an insulating interlayer on a connection region for providing wirings configured to electrically connect the memory cells, forming an etching mask pattern including etching mask pattern elements on a top sacrificial layer, forming blocking sidewalls on either sidewalls of each of the etching mask pattern element, forming a first photoresist pattern selectively exposing a first blocking sidewall furthermost from the memory cell region and covering the other blocking sidewalls, etching the exposed top sacrificial layer and an insulating interlayer to expose a second sacrificial layer, forming a second photoresist pattern by laterally removing the first photoresist pattern to the extent that a second blocking sidewall is exposed, and etching the exposed top and second sacrificial layers and the insulating interlayers to form a staircase shaped side edge portion.