Method for integrated circuit patterning

A method of forming a pattern for an integrated circuit, the method comprising:

• providing a substrate over which a hard mask layer is formed, the hard mask layer containing nitrogen;
• forming a resist layer over the hard mask layer, wherein a layer of resist scum forms in a first portion of the resist layer that is between a second portion of the resist layer and the hard mask layer;
• exposing the resist layer to a radiation for patterning;
• developing the resist layer in a developer to form trenches in the second portion, wherein the layer of resist scum remains substantially insoluble in the developer;
• filling a first material in the trenches, wherein the first material has a higher etch resistance than the resist layer;
• and
• etching the first material, the resist layer, and the layer of resist scum to expose the hard mask layer thereby forming a first pattern with a portion of the first material over a portion of the layer of resist scum over the hard mask layer.

A method of forming a pattern for an integrated circuit, the method comprising:

• forming a resist layer over a substrate, wherein a layer of substantially uniform resist scum is formed in a first portion of the resist layer adjacent to the substrate;
• forming trenches in a second portion of the resist layer that is over the first portion, wherein the first portion provides a floor for the trenches;
• forming a material layer in the trenches, wherein the material layer has a higher etch resistance in an etching process than that of the resist layer;
• and
• applying the etching process to the resist and material layers to expose the substrate, resulting in a patterned material layer over a portion of the resist layer over the substrate.