Overlay measurements are a critical part of modern semiconductor fabrication, but overlay targets have not scaled down in the way devices have. In this work, we produce overlay targets with very small footprint, consisting of just a few scattering nanoparticles in two separate device layers. Using moiré patterns to deterministically generate many overlay errors on a single chip, we demonstrate readout of the relative displacement between the two layers and show that calibration on one realization of the targets can be used for overlay measurements on subsequent instances. Our results suggest that using greater quantities of smaller overlay targets may benefit performance both directly and through finer sampling of deformation.

中文翻译：

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具有最小足迹目标的基于校准的叠加传感

覆盖测量是现代半导体制造的关键部分，但覆盖目标并没有像设备那样按比例缩小。在这项工作中，我们生产了占地面积非常小的覆盖目标，仅由两个单独的设备层中的几个散射纳米粒子组成。使用莫尔图案在单个芯片上确定性地生成许多重叠误差，我们展示了两层之间相对位移的读数，并表明对目标的一个实现的校准可用于后续实例的重叠测量。我们的结果表明，使用更大量的较小重叠目标可能会直接或通过更精细的变形采样来提高性能。