Method of manufacturing semiconductor device

A method of manufacturing a semiconductor device, the semiconductor device comprising a semiconductor substrate and a layer to be etched formed on the semiconductor substrate, wherein a groove and a concave portion are formed in the layer to be etched, and the concave portion is formed at a bottom of the groove and has a smaller opening portion than an opening portion of the groove, the method comprising:

• sequentially forming a first hard mask layer and a second hard mask layer on the layer to be etched;
• a first groove-forming mask pattern forming process which forms a groove-forming mask pattern which has a first pitch, is formed of the second hard mask layer, and is used as an etching mask when forming groove patterns, by
• forming a first resist layer on the second hard mask layer in order to form a first resist pattern that has a second pitch and is formed of the first resist layer, and
• etching the second hard mask layer using the first resist pattern as an etching mask;
• and
• a first concave portion-forming mask pattern forming process which forms a concave portion-forming mask pattern which has a third pitch substantially identical to the first pitch, is formed of the first hard mask layer, and is used as an etching mask when forming concave portion patterns, by
• sequentially forming a first organic layer and a second resist layer on the first hard mask layer, on which the groove-forming mask pattern is formed, in order to form a second resist pattern comprising the second resist layer having an opening portion that has a fourth pitch and the first organic layer having an opening portion that is connected to an opening portion of the second resist layer and has a smaller size than the opening portion of the second resist layer, and
• etching the first hard mask layer using the second resist pattern as an etching mask.