Fabrication process variations can significantly influence the performance and yield of nano-scale electronic and photonic circuits. Stochastic spectral methods have achieved great success in quantifying the impact of process variations, but they suffer from the curse of dimensionality. Recently, low-rank tensor methods have been developed to mitigate this issue, but two fundamental challenges remain open: how to automatically determine the tensor rank and how to adaptively pick the informative simulation samples. This paper proposes a novel tensor regression method to address these two challenges. We use a $\ell_{q}/ \ell_{2}$ group-sparsity regularization to determine the tensor rank. The resulting optimization problem can be efficiently solved via an alternating minimization solver. We also propose a two-stage adaptive sampling method to reduce the simulation cost. Our method considers both exploration and exploitation via the estimated Voronoi cell volume and nonlinearity measurement respectively. The proposed model is verified with synthetic and some realistic circuit benchmarks, on which our method can well capture the uncertainty caused by 19 to 100 random variables with only 100 to 600 simulation samples.
翻译:微光谱方法在量化过程变异的影响方面取得了巨大成功,但受到维度的诅咒。最近,为缓解这一问题,开发了低级高压方法,但有两个基本挑战依然存在:如何自动确定电压等级和如何适应性地选择信息模拟样本。本文件提出了应对这两项挑战的新颖的推回方法。我们用一个$@qq}/\ell ⁇ 2}美元组级规范来确定电压等级。由此产生的优化问题可以通过一个交替最小化解答器有效解决。我们还提议了一个两阶段适应性取样方法来降低模拟成本。我们的方法分别考虑通过估计的Voronoi细胞体积和非线性测量进行勘探和开发。拟议模型经过合成和一些现实的电路基准验证,我们的方法可以很好地捕捉到19至100个随机变量造成的不确定性,只有100至600个模拟样本。