LENOS: Latitude enhancement novel single layer lithography

Sachiko Ogawa, Sigeo Uoya, Hiroshi Kimura, Hitoshi Nagata
1989 Journal of Photopolymer Science and Technology (Fotoporima Konwakai shi)  
A single layer resist process called "LENOS" (Latitude Enhancement Novel Single Layer Lithography) is proposed. LENOS process needs only two steps in addition to a conventional single layer process, which are the soak step of a resist film into an alkaline solution after the prebake step and the bake step after the exposure step. These two steps accelerate the dissolution rate of the resist of the exposure area during development on the one hand, and form the insoluble layer to a developer at
more » ... to a developer at the resist surface of the unexposed area on the other. As the result, LENOS process enhances the difference in dissolution rate between the exposed area and the unexposed area. It is found that LENOS process shows from 1.3 to 3.0 times wider focus depth compared with the conventional single layer process and this focus depth is equal to that in the tri-layer resist process.
doi:10.2494/photopolymer.2.375 fatcat:xmmlvf5nordgte5ave4xpunkoy