Abstract: Disclosed are embodiments of a multi-layer stack and photolithography methods and systems that employ such a stack. The disclosed multi-layer stacks include a photoresist layer on an underlayer. The photoresist layer and underlayer are made of different materials, which are selected so that valence and conduction band offsets between the underlayer and photoresist layer create an effective electric field (i.e., so that the stack is “self-biased”). When areas of the photoresist layer are exposed to radiation during photolithography and the radiation passes through photoresist layer and excites electrons in the underlayer, this effective electric field facilitates movement of the radiation-excited electrons from the underlayer into the radiation-exposed areas of the photoresist layer in a direction normal to the interface between the underlayer and the photoresist layer.

Abstract: Disclosed are embodiments of a multi-layer stack and photolithography methods and systems that employ such a stack. The disclosed multi-layer stacks include a photoresist layer on an underlayer. The photoresist layer and underlayer are made of different materials, which are selected so that valence and conduction band offsets between the underlayer and photoresist layer create an effective electric field (i.e., so that the stack is “self-biased”). When areas of the photoresist layer are exposed to radiation during photolithography and the radiation passes through photoresist layer and excites electrons in the underlayer, this effective electric field facilitates movement of the radiation-excited electrons from the underlayer into the radiation-exposed areas of the photoresist layer in a direction normal to the interface between the underlayer and the photoresist layer.

Abstract: A litho-litho-etch double patterning method including forming a resist layer by coating a substrate with a resist composition; exposing the resist layer to a first radiant energy density of UV rays; forming a first pattern in the resist layer by developing the resist layer with a positive developer; exposing the resist layer to a second radiant energy density of UV rays; and forming a second pattern in the resist layer by developing the resist layer with a negative developer, the second pattern including one or more features of the first pattern.

Abstract: A litho-litho-etch double patterning method including forming a resist layer by coating a substrate with a resist composition; exposing the resist layer to a first radiant energy density of UV rays; forming a first pattern in the resist layer by developing the resist layer with a positive developer; exposing the resist layer to a second radiant energy density of UV rays; and forming a second pattern in the resist layer by developing the resist layer with a negative developer, the second pattern including one or more features of the first pattern.

Abstract: The disclosure is directed to a method for lithographic patterning. The method may include: exposing a photoresist to a radiant energy; developing the photoresist in a first developer, thereby creating an opening within the photoresist including sidewalls having a slant; and developing the photoresist in a second developer immediately after the developing of the photoresist in the first developer, thereby reducing the slant of the sidewalls of the opening. Where the photoresist is a positive tone development (PTD) photoresist, the first developer may include a positive developer, and the second developer may include a negative developer. Where the photoresist is a negative tone development (NTD) photoresist, the first developer may include a negative developer, and the second developer may include a positive developer.