With the development of semiconductor technology nodes, the sizes of standard cells become smaller and the number of standard cells is dramatically increased to bring into more functionality in integrated circuits (ICs). However, the shrinking of standard cell sizes causes many problems of ICs such as timing, power, and electromigration (EM). To tackle these problems, a new style structural pre-route (SPR) is proposed. Such type of pre-route is composed of redundant parallel metals and vias so that the low resistance and the redundant sub-structures can improve timing and yield. But the large area overhead becomes the major problem of inserting such pre-routes all over a design. In this paper, we propose a machine learning-based approach to predict the insertability of SPRs for placed designs. In addition, we apply a pattern visualization method by using a guided backpropagation technique to see in depth of our model and identify the problematic layout features causing SPR insertion failures. The experimental results not only show the excellent performance of our model, but also show that avoiding generating the identified critical features during legalization can improve SPR insertability compared to a commercial SPR-aware placement tool.

With the continuous scaling down of process nodes, standard cells become much smaller and cell counts are dramatically increased. Pin accessibility becomes one of the major issues causing design rule violations (DRVs). To tackle this problem, many recent works apply machine-learning-based techniques to predict whether a local region has DRV or not by regarding global routing (GR) congestion and local pin density as the main features during the training process. Empirically, however, DRV occurrence is not necessary to be strongly correlated with the two features in advanced nodes. In this article, we propose the first work of deep-learning-based DRV prediction using pin pattern as our major feature to directly identify whether a DRV will exist or not due to bad pin accessibility of the given pin pattern. Unlike most of the existing models that can only be used for DRV prediction, the proposed models can be applied to guide detailed placement for pin accessibility optimization during physical design. Experimental results show that the proposed models are greatly superior than those of previous studies in terms of all quantitative metrics. Additionally, the numbers of DRVs can be dramatically reduced by applying the proposed model-guided detailed placement flow.

With the development of advanced process nodes of semiconductor, the problem of pin access has become one of the major factors to impact the occurrences of design rule violations (DRVs) due to complex design rules and limited routing resource. Many state-of-the-art works address the problem of DRV prediction by adopting supervised machine learning approaches. However, those supervised learning approaches extract the labels of training data by generating a great number of routed designs in advance, giving rise to large effort on training data preparation. In addition, the pre-trained model could hardly predict unseen data and thus may not be applied to predict other designs containing cells that are not used in the training data. In this paper, we propose the first work of cell library-based pin accessibility prediction (PAP) by using active learning techniques. A given set of standard cell libraries is served as the only input for model training. Unlike most of existing studies that aim at design-specific training, we propose a library-based model which can be applied to all designs referencing to the same standard cell library set. Experimental results show that the proposed model can be applied to predict two different designs with different reference library sets. The number of remaining DRVs and M2 shorts of the designs optimized by the proposed model are also much fewer than those of design-specific models.

With the continuous scaling down of process nodes, standard cells become much smaller and cell counts are dramatically increased. Pin accessibility becomes one of the major issues causing design rule violations (DRVs). To tackle this problem, many recent works apply machine learning-based techniques to predict whether a local region has DRV or not by regarding global routing (GR) congestion and local pin density as the main features during the training process. Empirically, however, DRV occurrence is not necessary to be strongly correlated with the two features in advanced nodes. In this paper, we propose the first work of deep learning-based DRV prediction using pin pattern as our major feature to directly identify whether a DRV will exist or not due to bad pin accessibility of the given pin pattern. Unlike most of existing models that can only be used for DRV prediction, the proposed models can be applied to guide detailed placement for pin accessibility optimization during physical design. Experimental results show that the proposed models are greatly superior than those of previous studies in terms of all quantitative metrics. Additionally, the numbers of DRVs can be dramatically reduced by applying the proposed model-guided detailed placement flow.