Electronic Design Automation (EDA) tools are central to Very Large Scale Integration (VLSI) design, where numerous parameters govern the Quality-of-Result (QoR) metrics, including performance, power, and area. The high dimensionality of the parameter space, coupled with complex interactions, makes manual tuning inefficient and hinders the scalability of automated methods. Existing methods typically treat parameters as flat vectors, neglecting the EDA flow’s hierarchical causal structure, where early-stage decisions constrain later downstream stages. To address this, we propose CausalTuner, a causality-aware design space exploration framework for efficient parameter tuning. It employs a hybrid causal attention mechanism to capture stage-wise parameter interactions and embeds them into deep kernel Gaussian processes for accurate and generalizable surrogate modeling. The causal exploration strategies enhance sampling efficiency. Experiments show that CausalTuner outperforms state-of-the-art methods in both final QoR and efficiency.

Optimizing Electronic Design Automation (EDA) tool parameters with only dozens of affordable evaluations represents one of the most challenging problems in today’s EDA flow management, where each experiment costs hours to days yet directly impacts final PPA outcomes. While Bayesian Optimization (BO) naturally fits such sample-constrained scenarios, it models the entire EDA flow as a monolithic formulation, blindly ignoring the sequential structure that each stage in the EDA flow affects the next. In this work, we propose a stage-aware optimization framework that fundamentally rethinks EDA parameter tuning. The proposed stage-aware Gaussian process explicitly models cascading relationships between EDA stages through interconnected GP layers, extracting abundant information from each expensive evaluation. To better meet realistic needs, we further introduce Expected Hypervolume Improvement (EHVI)-Efficiency, a time-aware acquisition function that exploits evaluation runtime estimation and EDA tools’ checkpoint reuse to balance design metrics’ expected improvement against EDA flow’s computational cost. Experiments and ablation studies on 6 designs across 3 process nodes demonstrate the effectiveness of our proposed method.

Full-chip inverse lithography techniques (ILT) represent an advanced methodology for next-generation mask optimization, enhancing sub-wavelength patterning but often facing prohibitive computational costs. State-of-the-art methods rely on iterative first-order optimizers, which exhibit slow convergence, often requiring hundreds of iterations. This inefficiency is compounded by the high overhead of repeated Fast Fourier Transform (FFT) operations and inter-GPU communication per iteration. To overcome this fundamental bottleneck, we propose a scalable second-order optimizer for full-chip ILT. Our approach leverages second-order curvature information via the Hessian matrix to achieve dramatically faster convergence and superior pattern fidelity compared to conventional first-order methods. Crucially, we address the prohibitive cost of exact Hessian computation by employing Hutchinson’s method to efficiently approximate the Hessian diagonal. Combined with exponential moving average (EMA) and gradient modulation techniques, our optimizer achieves significant performance gains. Experimental results demonstrate substantial improvements in both runtime efficiency (reduced iterations) and solution quality (enhanced pattern fidelity) compared to existing first-order ILT methods, paving the way for practical full-chip ILT.

Layout pattern generation provides dataset support to numerous Design for Manufacturability (DFM) studies, with different research objectives requiring distinct styles of layout patterns. However, existing layout pattern generation methods only support random generation or limited conditional generation based on image-text pairs annotated for specific tasks, which fails to meet the diverse requirements of downstream tasks. To address this limitation, we propose ForgePattern, a flexible layout pattern generation framework that accommodates diverse task-specific requirements through adaptive selection among customizable reward functions. ForgePattern leverages a customized diffusion model as the generative backbone and incorporates reinforcement learning to directly optimize the diffusion model. By maximizing the expected reward of the reinforcement learning objective, ForgePattern aligns the generated layout patterns with specific requirements without requiring additional data collection or human annotation. Experimental results on challenging layout pattern generation tasks demonstrate that ForgePattern can effectively generate high-quality layout patterns while meeting diverse customization requirements.

The post-exposure bake (PEB) process is a critical step in semiconductor lithography, directly impacting resist profile accuracy and circuit pattern fidelity. Precise modeling of PEB is essential for controlling photoacid diffusion and inhibitor reactions. In this paper, we introduce SDM-PEB, an advanced modeling framework designed to enhance the accuracy of PEB simulations by capturing both intra-layer spatial dependencies and inter-layer depthwise interactions. Leveraging a unique hierarchical feature extractor with overlapped patch merging and efficient self-attention, our approach effectively captures both coarse and fine features at multiple scales. The spatial-depthwise Mamba-based attention unit, centered on a customized selective scan and structured state space model, efficiently captures spatial and depthwise dependencies, enabling precise 3D PEB simulation. Additionally, a PEB focal loss and differential depth divergence regularization term improve the sensitivity to both spatial and depthwise variations, addressing inherent data imbalances in 3D PEB simulations. Our framework is validated with commercial rigorous model, and experimental results demonstrate that the SDM-PEB outperforms previous methods in accuracy and efficiency.

This paper presents a novel curvilinear optical proximity correction (OPC) framework. The proposed approach involves representing mask patterns with control points, which are interconnected through cardinal splines. Mask optimization is achieved by iteratively adjusting these control points, guided by lithography simulation. To ensure compliance with mask rule checking (MRC) criteria, we develop comprehensive methods for checking width, space, area, and curvature. Additionally, to match the performance of inverse lithography techniques (ILT), we design algorithms to fit ILT results and resolve MRC violations. Extensive experiments demonstrate the effectiveness of our methodology, highlighting its potential as a viable OPC/ILT alternative.

Model-based optical proximity correction (OPC) with subresolution assist feature (SRAF) generation is a critical standard practice for compensating lithography distortions in the fabrication of integrated circuits at advanced technology nodes. Typical model-based OPC and SRAF algorithms involve the selection of user-controlled rule parameters. Conventionally, these rules are heuristically determined and applied globally throughout the correction regions, which can be time consuming and require expert knowledge of the tool. Additionally, the correlations of rule parameters to the objectives are highly nonlinear. All these factors make designing a high-performance OPC engine for complex metal designs a nontrivial task. This article proposes RuleLearner, a comprehensive mask optimization system designed for SRAF generation and model-based OPC in real industrial scenarios. The proposed framework learns from the guidance of an information-augmented inverse lithography technique engine, which, although expressive for complex designs, is expensive to generate refined masks for a whole set of design clips. Considering the nonlinearity and the tradeoff between local and global performance, the extracted rule value distributions are further optimized with customized natural gradients. The sophisticated SRAF generation, the edge segmentation and movements are then guided by the rule parameter. Experimental results show that RuleLearner can be applied across different complex design patterns and achieve the best lithographic performance and computational efficiency.

The complexity of microarchitecture design has surged due to the expanding design space and time-intensive verification processes. Existing regression-based machine learning methods struggle with inaccurate estimations because of limited training samples. To address these challenges, we propose Rank-DSE, a novel framework for microarchitecture design space exploration (DSE) that leverages a Neural Pareto Comparator (NPC) to directly model the comparative relationships between different architecture designs. Rank-DSE bypasses the inaccuracies of absolute PPA (performance, power, area) predictions by focusing on relative comparisons. The NPC computes the probability of one architecture dominating another and employs semi-supervised learning to reduce the reliance on labeled data. Additionally, a reinforcement-learning-based sampling scheme with an updating baseline Pareto set accelerates the exploration process. Experimental results on the ICCAD 2021 benchmark demonstrate that Rank-DSE achieves superior search quality and cost-efficiency compared to state-of-the-art methods. Specifically, Rank-DSE improves hypervolume by up to 7% while reducing exploration cost by 53.09% compared to cutting-edge approaches. These results highlight the advantages of Rank-DSE in terms of efficiency and effectiveness for microarchitecture DSE.

Logic synthesis pre-optimization involves applying a sequence of transformations called synthesis flow to reduce the circuit's Boolean logic graph, like AIG. However, the challenge lies in selecting and arranging these transformations due to the exponentially expanding solution space. In this work, we propose CBTune, a novel online learning framework that utilizes a contextual bandit algorithm to explore the solution space and generate synthesis flows efficiently. We develop the Syn-LinUCB algorithm as the agent, which incorporates circuit characteristics and leverages long-term payoffs to guide decision-making, thus ef-fectively preventing getting trapped in local optima. Experimental results show that our framework achieves the optimal synthesis flow with a lower time cost, substantially reducing the number of AIG nodes and 6-LUTs compared to SOTA approaches.

Optical proximity correction (OPC) is a widely used technique to enhance the printability of designs in various foundaries. Recently, there has been a growing interest in using rigorous numerical optimization and machine learning to improve the robustness and efficiency of OPC. Our research focuses on developing a self-adaptive OPC framework that leverages the properties of pattern distribution and repetition in design layouts to optimize the correction process. We observe that different sub-regions in a design layer have varying pattern complexities, and many patterns repeat themselves throughout the layout. By exploiting these properties, we propose a framework that adaptively selects the most suitable OPC solvers from an extensible pool to optimize the correction process for each pattern based on its complexity. This approach allows for a co-optimization of speed and accuracy. Additionally, we introduce a graph-based dynamic pattern library that reuses optimized masks for repeated patterns, further accelerating the OPC flow. Our experimental results demonstrate a significant improvement in both performance and efficiency using our proposed framework.

Inverse lithography technique (ILT) is one of the most widely used resolution enhancement techniques (RETs) to compensate for the diffraction effect in the lithography process. However, ILT suffers from runtime overhead issues with the shrinking size of technology nodes. In this article, our proposed L2O-ILT framework unrolls the iterative ILT optimization algorithm into a learnable neural network with high interpretability, which can generate a high-quality initial mask for fast refinement. Experimental results demonstrate that our method achieves better performance on both mask printability and runtime than the previous methods.

The microarchitecture design of processors faces growing complexity due to expanding design space and time-intensive verification processes. Utilizing historical design task data can improve the search process, but managing distribution discrepancies between different source tasks is essential for enhancing the search method's generalization ability. In light of this, we introduce IT-DSE, a microarchitecture searching framework with the surrogate model pre-trained to absorb knowledge from previous design tasks. The Feature Tokenizer-Transformer (FT-Transformer) serves as a backbone, facilitating feature extraction from source tasks even with varied design spaces. Concurrently, the invariant risk minimization (IRM) paradigm bolsters generalization ability under data distribution discrepancies. Further, IT-DSE exploits a combination of multi-objective Bayesian optimization and a model ensemble to discover Pareto-optimal designs Experimental results indicate that IT-DSE effectively harnesses the knowledge of existing microarchitecture designs and uncovers designs that outperform previous methods in terms of power, performance, and area (PPA).

As one of the key techniques for resolution enhancement technologies (RETs), optical proximity correction (OPC) suffers from prohibitive computational costs as feature sizes continue to shrink. Inverse lithography techniques (ILTs) treat the mask optimization process as an inverse imaging problem, yielding high-quality curvilinear masks. However, ILT methods often fall short of printability and manufacturability due to their time-consuming procedures and excessive computational overhead. In this article, we propose DevelSet, a potent metal layer OPC engine that replaces discrete pixel-based masks with implicit level set-based representations. With a GPU-accelerated lithography simulator, DevelSet achieves end-to-end mask optimization using a neural network to provide quasi-optimized level set initialization and further evolution with a CUDA-based mask optimizer for fast convergence. The backbone of DevelSet-Net is a transformer-based multibranch neural network that offers a parameter selector to eliminate the need for manual parameter initialization. Experimental results demonstrate that the DevelSet framework outperforms state-of-the-art approaches in terms of printability while achieving fast runtime performance (around 1 s). We expect this enhanced level set technique, coupled with a CUDA/DNN accelerated joint optimization paradigm, to have a substantial impact on industrial mask optimization solutions.

As the feature size of advanced integrated circuits keeps shrinking, resolution enhancement techniques (RETs) are utilized to improve the printability in the lithography process. Optical proximity correction (OPC) is one of the most widely used RETs aiming at compensating the mask to generate a more precise wafer image. In this article, we put forward a level-set-based OPC approach with high mask optimization quality and fast convergence. In order to suppress the disturbance of the condition fluctuation in the lithography process, we propose a new process window-aware cost function. Then, a novel momentum-based evolution technique is adopted, which demonstrates substantial improvement. We also propose a self-adaptive conjugate gradient method that promises a higher optimization stability and less consuming time. Moreover, the graphics processing unit (GPU) is leveraged for accelerating the proposed algorithm. We take the output masks from a machine learning-based mask optimization flow as the input and work as the postprocess to refine the quasi-optimized masks. Experimental results on ICCAD 2013 benchmarks show that our algorithm outperforms all previous OPC algorithms in both solution quality and runtime overhead.

In the lithography process, subresolution assist features (SRAFs), as an essential resolution enhancement technique (RET), is applied to improve the pattern fidelity and enlarge the process window. In this article, we propose a robust constraint-aware SRAF generation method based on continuous transmission mask (CTM). The intensity distribution on the CTM is extracted to guide the SRAF generation. The SRAF insertion also honors the design rules, which is formulated as integer programming with quadratic constraints and solved by a fast yet efficient algorithm. A fast probe-based SRAF evolution method is proposed to determine the shapes of SRAFs. The effectiveness and efficiency are demonstrated based on the experimental results.

Optical proximity correction (OPC) is a widely-used resolution enhancement technique (RET) for printability optimization. Recently, rigorous numerical optimization and fast machine learning are the research focus of OPC in both academia and industry, each of which complements the other in terms of robustness or efficiency. We inspect the pattern distribution on a design layer and find that different sub-regions have different pattern complexity. Besides, we also find that many patterns repetitively appear in the design layout, and these patterns may possibly share optimized masks. We exploit these properties and propose a self-adaptive OPC framework to improve efficiency. Firstly we choose different OPC solvers adaptively for patterns of different complexity from an extensible solver pool to reach a speed/accuracy co-optimization. Apart from that, we prove the feasibility of reusing optimized masks for repeated patterns and hence, build a graph-based dynamic pattern library reusing stored masks to further speed up the OPC flow. Experimental results show that our framework achieves substantial improvement in both performance and efficiency.

As the feature size of advanced integrated circuits keeps shrinking, resolution enhancement technique (RET) is utilized to improve the printability in the lithography process. Optical proximity correction (OPC) is one of the most widely used RETs aiming at compensating the mask to generate a more precise wafer image. In this paper, we put forward a level-set based OPC with high mask optimization quality and fast convergence. In order to suppress the disturbance of the condition fluctuation in lithography process, we propose a new process window-aware cost function. Then, a novel momentum-based evolution technique is adopted, which demonstrates substantial improvement. Moreover, graphics processing unit (GPU) is leveraged for accelerating the proposed algorithm. Experimental results on ICCAD 2013 benchmarks show that our algorithm outperforms all previous OPC algorithms in terms of both solution quality and runtime overhead.

With the feature size continuously shrinking in advanced technology nodes, mask optimization is increasingly crucial in the conventional design flow, accompanied by an explosive growth in prohibitive computational overhead in optical proximity correction (OPC) methods. Recently, inverse lithography technique (ILT) has drawn significant attention and is becoming prevalent in emerging OPC solutions. However, ILT methods are either time-consuming or in weak performance of mask printability and manufacturability. In this paper, we present DevelSet, a GPU and deep neural network (DNN) accelerated level set OPC framework for metal layer. We first improve the conventional level set-based ILT algorithm by introducing the curvature term to reduce mask complexity and applying GPU acceleration to overcome computational bottlenecks. To further enhance printability and fast iterative convergence, we propose a novel deep neural network delicately designed with level set intrinsic principles to facilitate the joint optimization of DNN and GPU accelerated level set optimizer. Experimental results show that DevelSet framework surpasses the state-of-the-art methods in printability and boost the runtime performance achieving instant level (around 1 second).