Method of fabricating semiconductor device

Abstract

A method of fabricating a semiconductor device include providing a substrate including cell and peripheral regions, forming a cell gate structure on the cell region, forming a peripheral gate structure on the peripheral region, forming a bit-line structure on the cell region, forming a preliminary pad layer covering the bit-line structure and the peripheral gate structure, and etching the preliminary pad layer to form a landing pad and a peripheral conductive pad. The etching the preliminary pad layer includes forming a first mask structure on the preliminary pad layer, forming a second mask structure on the first mask structure, forming a first photoresist layer on the second mask structure, and using the first photoresist layer as an etching mask to etch the second mask structure. The first photoresist layer includes a first line opening overlapping the cell region, and peripheral resist patterns overlapping the peripheral region.