Method for fabricating semiconductor device

A method for fabricating a semiconductor device, comprising:

• forming an insulating layer on an etch-target layer;
• forming at least one sacrificial layer on the insulating layer, wherein the sacrificial layer is at least one layer selected from the group consisting of a polysilicon layer, an Al layer, a W layer, a WSix layer, a WN layer, a Ti layer, a TiN layer, a TiSix layer, a TiAlN layer, a TiSiN layer, a Pt layer, an Ir layer, an IrO2 layer, a Ru layer, a RuO2 layer, an Ag layer, an Au layer, a Co layer, a TaN layer, a CrN layer, a CoN layer, MoN layer, a MoSix layer, an Al2O3 layer, an AlN layer, a PtSix layer, and CrSix layer, and wherein x is 1 or 2;
• forming an antireflection coating layer on the sacrifice layer;
• forming a photoresist pattern on the antireflection coating layer;
• sequentially performing at least three sequential etching processes, including:
• (a) etching the antireflection coating layer and the sacrificial layer using the photoresist pattern as an etching mask without substantially etching the insulating layer to form a sacrificial hard mask;
• (b) etching the insulating layer using the sacrificial hard mask as an etching mask without substantially etching the etch-target layer to form a hard mask;
• and
• (c) etching the etch-target layer using the sacrificial hard mask and the hard mask as etching masks to form a predetermined number of patterns.

A method for fabricating a semiconductor device, comprising:

• forming an insulating layer for a hard mask on an etch-target layer;
• forming at least one sacrificial layer on the insulating layer, wherein the sacrificial layer includes tungsten (W);
• forming a photoresist pattern on the sacrificial layer;
• forming a sacrificial hard mask by etching the sacrificial layer using the photoresist pattern as an etching mask and using a plasma of a SF6/N2 gas mixture having a mixing ratio within a range of between about 0.10 to about 0.60;
• forming the hard mask by etching the insulating layer using the sacrificial hard mask as an etching mask;
• and
• forming a predetermined number of patterns by etching the etch-target layer using the sacrificial hard mask and the hard mask as etching masks.

A method for fabricating a semiconductor device, comprising:

• forming an insulating layer for a hard mask on an etch-target layer;
• forming at least one sacrificial layer on the insulating layer for the hard mask, wherein the sacrificial layer includes tungsten (W);
• forming an antireflection layer on the sacrifice layer;
• forming a photoresist pattern on the antireflection coating layer;
• forming a sacrificial hard mask by etching the antireflection layer and the sacrificial layer using the photoresist pattern as an etching mask, and using a plasma of a SF6/N2 gas mixture having a mixing ratio within a range of between about 0.10 to about 0.60;
• forming a hard mask by etching the insulating layer using the sacrifice hard mask as an etching mask;
• and
• forming a predetermined number of patterns by etching the etch-target layer with the sacrifice hard mask and the hard mask as etching masks.