Semiconductor device using hard mask and method for fabricating the same

The technology relates to a semiconductor device including a hard mask easy to strip and capable of implementing a fine pattern with a high etch selectivity. According to an embodiment of the disclosure, a method for fabricating a semiconductor device comprises forming an etching target layer, forming a hard mask layer on the etching target layer, the hard mask layer including a first boron-doped silicon layer and a second boron-doped silicon layer on the first boron-doped silicon layer, and etching the etching target layer using the hard mask layer as an etching barrier, wherein the second boron-doped silicon layer has a larger boron concentration than the first boron-doped silicon layer.