As the size of structures of advanced integrated circuits has decreased, manufacturers are turning to a micro-lithography technique called immersion lithography, because of its improved resolution capability. In immersion lithography, an immersion fluid is placed between the optical lens and a photoresist layer. The immersion fluid provides considerably higher resolution than conventional photoirradiation in air. However, in many photoresist systems, components of the photoresist leach out into the immersion fluid and/or the immersion fluid penetrates into the photoresist thus degrading performance. Therefore, there is a need for a method to prevent interaction between photoresist layers and immersion fluid in an immersion lithography system.
USPTO Backgrounds
USPTO Backgrounds