Patent attributes
When a via-hole 26 and an interconnection trench 32 are formed in an interconnection films 16, 18 by using as a mask a hard mask 20 covering the region except via-hole forming region, and a hard mask 22 covering the region except an interconnection trench forming region, the hard mask 20 is isotropically etched to expose the upper surface of the inter-layer insulating film 18 at a periphery of the via-hole forming region and leave the hard mask 20 in the interconnection trench forming region except the periphery, and then the hard mask 20 and the insulating films 18, 16 are anisotropically etched, whereby the via-hole 26 having increased-width portion 34 at the upper part, and the interconnection trench 32 connected to the via-hole 26 at the increased-width portions 26 are formed.
