Litho-litho-etch double patterning method

A double patterning method comprising:

• forming a resist layer by coating a substrate with a resist composition wherein solubility of the resist composition in a positive developer increases upon irradiation with ultraviolet (UV) rays of a first radiant energy density and solubility of the resist composition in a negative developer decreases upon irradiation with UV rays of a second radiant energy density, the second radiant energy density of UV rays being greater than the first radiant energy density of UV rays;
• exposing the resist layer to the first radiant energy density of UV rays through at least one first opening in a first hardmask;
• forming a first pattern in the resist layer by developing the resist layer with the positive developer, the at least one first opening in the first hardmask creating the first pattern;
• exposing the resist layer to the second radiant energy density of UV rays through at least one second opening in a second hardmask, the at least one second opening encompassing and being larger than the at least one first opening in the first hardmask, the at least one second opening in the second hardmask exposing at least one portion of the resist layer not exposed to the first radiant energy density of UV rays by the at least one first opening in the first hardmask;
• and
• forming a second pattern in the resist layer by developing the resist layer with the negative developer, the at least one portion of the resist layer exposed to the second radiant energy density of UV rays creating the second pattern, the second pattern including one or more features of the first pattern;
• wherein the exposing of the resist layer to the first radiant energy density of UV rays generates an acid in an area substantially equal to an area of the resist layer exposed to the first radiant energy density of UV rays, wherein a concentration of the acid remaining in the resist layer after the developing of the resist layer with the negative developer is substantially uniform throughout the resist layer.

A double patterning method comprising:

• forming a resist layer by coating a substrate with a resist composition;
• exposing the resist layer to a first radiant energy density of ultraviolet (UV) rays through at least one first opening in a first hardmask;
• forming a first pattern in the resist layer by developing the resist layer with a positive developer, the at least one first opening in the first hardmask creating the first pattern;
• exposing the resist layer to a second radiant energy density of UV rays through at least one second opening in a second hardmask, the at least one second opening encompassing and being larger than the at least one first opening in the first hardmask, the at least one second opening in the second hardmask exposing at least one portion of the resist layer not exposed to the first radiant energy density of UV rays by the at least one first opening in the first hardmask;
• and
• forming a second pattern in the resist layer by developing the resist layer with a negative developer, the at least one portion of the resist layer exposed to the second radiant energy density of UV rays creating the second pattern, the second pattern including one or more features of the first pattern;
• wherein the forming of the first and second patterns in the resist layer creates at least two resist coating features.