Computational vibration mitigation using phase interpolation in digital holographic microscopy for overlay metrology.

Digital holographic microscopy retrieves amplitude and phase information of an image which allows us to computationally correct for imperfections in the imaging optics. However, digital holographic microscopy is an interferometric technique that is inherently sensitive to undesired phase variations between object and reference beam. These phase variations lower the fringe contrast if they are integrated over a finite exposure time which leads to a reduced amplitude of the retrieved image.

Field-position dependent apodization in dark-field digital holographic microscopy for semiconductor metrology.

Measuring overlay between two layers of semiconductor devices is a crucial step during electronic chip fabrication. We present dark-field digital holographic microscopy that addresses various overlay metrology challenges that are encountered in the semiconductor industry. We present measurement results that show that the point-spread function of our microscope depends on the position in the field-of-view.

Spatial coherence measurement and partially coherent diffractive imaging using self-referencing holography.

The complete characterization of spatial coherence is extremely difficult because the mutual coherence function (MCF) is a complex-valued function of four independent Cartesian coordinates. This difficulty limits the ability to control and to optimize the spatial coherence in a broad range of key applications. Here we propose an efficient and robust scheme for measuring the complete MCF of an arbitrary partially coherent beam using self-referencing holography, which does not require any prior knowledge or making any assumptions about the MCF.