| 摘要 |
<p>When an interconnection structure is formed by a trench-first dual damascene method, a first hard mask (18) for forming via holes and a second hard mask (19) for forming interconnection trenches are sequentially formed on an interlayer insulating film (17), openings (18a) are formed in the first hard mask (18) with the second hard mask (19) as a mask, openings (18b) are formed by laterally extending the openings (18a) by isotropic etching, via holes (24) are formed by etching the interlayer insulating film (17) with the first hard mask (18) and second hard mask (19) as a mask, and interconnection tranches (17b), each communicating with the via hole (24), are formed by etching the interlayer insulating film (17) with the second hard mask (19) as a mask.</p> |
