Optimal Phase Conflict Removal for Layout of Dark Field Alternating Phase Shifting Masks

We describe new, efficient algorithms for layout modification and phase assignment for dark field alternating-type phase-shifting masks in the single-exposure regime. We make the following contributions. First, we suggest new 2-coloring and compaction approach that simultaneously optimizes layout and phase assignment which is based on planar embedding of an associated conflict graph. We also describe additional approaches to co-optimization of layout and phase assignment for alternating PSM. Second, we give optimal and fast algorithms to minimize the number of phase conflicts that must be removed to ensure 2-colorability ofthe conflict graph. We reduce this problem to the T-join problem which asks for a minimum weight edgeset A such that a node u is incident to an odd number of edges of A i u belongs to a given node subset T of a weighted graph. Third, we suggest several practical algorithms for the T-join problem. In sparse graphs, our algorithms are faster than previously known methods. Computational experience with industrial VLSI layout benchmarks shows the advantages of the new algorithms

Design for manufacturing (DFM) in submicron VLSI design

As VLSI technology scales to 65nm and below, traditional communication between design and manufacturing becomes more and more inadequate. Gone are the days when designers simply pass the design GDSII file to the foundry and expect very good man¬ufacturing and parametric yield. This is largely due to the enormous challenges in the manufacturing stage as the feature size continues to shrink. Thus, the idea of DFM (Design for Manufacturing) is getting very popular. Even though there is no universally accepted definition of DFM, in my opinion, one of the major parts of DFM is to bring manufacturing information into the design stage in a way that is understood by designers. Consequently, designers can act on the information to improve both manufacturing and parametric yield. In this dissertation, I will present several attempts to reduce the gap between design and manufacturing communities: Alt-PSM aware standard cell designs, printability improve¬ment for detailed routing and the ASIC design flow with litho aware static timing analysis. Experiment results show that we can greatly improve the manufacturability of the designs and we can reduce design pessimism significantly for easier design closure

Geometric correction of historical Arabic documents

Geometric deformations in historical documents significantly influence the success of both Optical Character Recognition (OCR) techniques and human readability. They may have been introduced at any time during the life cycle of a document, from when it was first printed to the time it was digitised by an imaging device. This Thesis focuses on the challenging domain of geometric correction of Arabic historical documents, where background research has highlighted that existing approaches for geometric correction of Latin-script historical documents are not sensitive to the characteristics of text in Arabic documents and therefore cannot be applied successfully. Text line segmentation and baseline detection algorithms have been investigated to propose a new more suitable one for warped Arabic historical document images. Advanced ideas for performing dewarping and geometric restoration on historical Arabic documents, as dictated by the specific characteristics of the problem have been implemented.In addition to developing an algorithm to detect accurate baselines of historical printed Arabic documents the research also contributes a new dataset consisting of historical Arabic documents with different degrees of warping severity.Overall, a new dewarping system, the first for Historical Arabic documents, has been developed taking into account both global and local features of the text image and the patterns of the smooth distortion between text lines. By using the results of the proposed line segmentation and baseline detection methods, it can cope with a variety of distortions, such as page curl, arbitrary warping and fold