New graph bipartizations for double-exposure, bright field alternating phase-shift mask layout

Abstract-- We describe new graph bipartization algorithms for layout modification and phase assignment of bright-field alternating phaseshifting masks (AltPSM) [25]. The problem of layout modification for phase-assignability reduces to the problem of making a certain layoutderived graph bipartite (i.e., 2-colorable). Previous work [3] solves bipartization optimally for the dark field alternating PSM regime. Only one degree of freedom is allowed (and relevant) for such a bipartization: edge deletion, which corresponds to increasing the spacing between features in order to remove phase conflict. Unfortunately, dark-field PSM is used only for contact layers, due to limitations of negative photoresists. Poly and metal layers are actually created using positive photoresists and bright-field masks. In this paper, we define a new graph bipartization formulation that pertains to the more technologically relevant bright-field regime. Previous work [3] does not apply to this regime. This formula...

• Type: Conference
• Year: 2001
• Where: ASPDAC
• Authors: Andrew B. Kahng, Shailesh Vaya, Alexander Zelikovsky
• Keywords: ASPDAC 2001, Edge Deletion, Graph Bipartization, Hardware, Node Deletion