Abstract: The defects in manufacturing of microelectronic devices could be significant fatal factor for product quality. So a variety of defect inspection technology may be developed or improved. The Coherent Diffractive Imaging （CDI） is a lensless technology, which provides a flexible, high resolution and non-destructive way to locate internal defects in microelectronic devices. However, there are still some problems to be solved in the CDI. A masking approach is developed to eliminate simultaneous twin-images in phase retrieval process. The simulation shows it is feasible. Simulation results also demonstrate the masking approach has a faster convergence speed. Moreover, the new improvement is not sensitive to the aperture size error in iterative process. The technical basis could be established for the CDI measurements.

Key words: defect inspection, Coherent Diffractive Imaging（CDI）, phase retrieval, iterative algorithms, twin-images

摘要： 微电子器件生产中的缺陷对于最终的产品质量是一个重大的关键因素。因此需要发展和提升一系列缺陷检测技术。无透镜的相干衍射成像技术提供了一种灵活的、高分辨的、无损的方式用于检测微电子器件的内部缺陷。然而在相干衍射成像中仍存在着一些问题。针对相位恢复过程中的孪生像问题提出了一种改变光阑形状的方法。仿真表明这种方法是可行的。仿真还表明这种改变光阑形状的方法有更快的收敛速度。不仅如此，这种新的改进对迭代过程中的光阑尺寸误差也不敏感。这将为相干衍射成像用于测量奠定技术基础。

关键词: 缺陷检测, 相干衍射成像, 相位恢复, 迭代算法, 孪生像