摘要 |
A method includes forming an interlayer dielectric layer including a contact plug over a semiconductor substrate, forming a metal layer, a hard mask layer, and an anti-reflection layer over the interlayer dielectric layer, forming a photoresist pattern over the anti-reflection layer, etching the anti-reflection layer in a primary etching process, using the photoresist pattern as an etching mask, to form an anti-reflection pattern, forming a first polymer layer over a surface of the anti-reflection pattern and the photoresist pattern by using polymer generated in the primary etching process, etching the hard mask layer in a secondary etching process, by using the anti-reflection pattern, the photoresist pattern, and the first polymer layer as an etching mask, to form a hard mask, and etching the metal layer in a tertiary etching process, by using the photoresist pattern, the anti-reflection pattern, the first polymer layer, and the hard mask as an etching mask, to form a metal interconnection. A first polymer layer is formed over the surface of the anti-reflection pattern and the photoresist pattern such that the design rule of the anti-reflection pattern is determined by polymer generated through the primary etching process.
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