Holographic 3D imaging of microstructures

A volume holographic matched filter is used for three-dimensional imaging of silicon microstructures. The filter is designed by recording a hologram that is matched to the object depth, allowing confocal imaging of the structure. Confocal imaging of micro devices provides the capability to image the performance of the device, which is not possible in scanning-electron-microscopes (SEM). A matched holographic filter can also provide more information about the device than regular confocal imaging. We present a scanned image of a silicon wafer with micro-fabricated trenches.