Pattern forming method and method of manufacturing semiconductor device

A pattern forming method, comprising:

• forming a hard mask layer above a process object;
• forming a core pattern with a predetermined shape above the hard mask layer;
• forming a spacer film above the hard mask layer where the core pattern is formed;
• etching back the spacer film such that a top face of the core pattern is exposed and a top face of the hard mask layer between the core patterns is exposed;
• forming an embedded layer above the hard mask layer so as to embed between the core patterns whose peripheral areas are surrounded by the spacer film;
• removing the core pattern and the embedded layer simultaneously to form a spacer pattern including the spacer film;
• processing the hard mask layer using the spacer pattern as a mask;
• and
• forming a pattern on the process object using the processed hard mask layer as a mask,
• wherein,
• in the formation of the embedded layer, a plurality of layers of embedded films are stacked, the embedded films being formed of organic films having different degree of shrinkage by irradiating light or applying heat, and
• in the plurality of layers of embedded films, an upper embedded film has a larger degree of the shrinkage than a degree of the shrinkage of a lowest embedded film.