Defect reduction in immersion lithography
OwnerYayi Weiinventor
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Abstract
An embodiment of the invention provides a method for forming a semiconductor device. A method comprises forming a resist on a substrate. A photoacid generator (PAG) is dispersed homogeneously in the resist. The method includes concentrating the PAG near a surface of the resist by evaporating a solvent from the resist. In an embodiment, the concentrating includes heating the resist to a first temperature. Embodiments include forming a topcoat layer on the resist after concentrating the PAG. An embodiment includes exposing the photoresist layer to a level of radiation suitable for generating a photoacid within the photoresist layer. Other embodiments include heating the exposed photoresist layer to a second temperature, the second temperature sufficient to deprotect the photoresist layer
Claims20
A method for forming a semiconductor device, the method comprising:
- forming a resist on a substrate, the resist comprising a photoacid generator (PAG) dispersed substantially homogeneously in the resist;
- concentrating the PAG near a surface of the resist by evaporating a solvent from the resist;
- and
- forming a topcoat layer on the resist after concentrating the PAG.
An immersion lithography method for forming an integrated circuit feature having a critical dimension, the method comprising:
- forming a photoresist layer on a substrate, wherein the photoresist layer includes a photoacid generator (PAG);
- heating the photoresist layer to a first temperature;
- forming a topcoat on the photoresist layer;
- exposing the photoresist layer to a level of radiation suitable for generating a photoacid within the photoresist layer;
- and
- heating the exposed photoresist layer to a second temperature, the second temperature sufficient to deprotect the photoresist layer.
A method of patterning a resist, the method comprising:
- forming a resist on a substrate, wherein the resist comprises a photoacid generator (PAG);
- concentrating the PAG at a surface of the resist by baking the resist at a first temperature;
- forming a topcoat layer on the resist after concentrating the PAG;
- generating a photoacid in the resist;
- and
- reacting the resist with the photoacid.
Dependencies are inferred from the claim text.