Wide-area topography using reflection phase microscopy for surface inspection

In this study, we demonstrated an inspection system utilizing reflection phase microscopy to enhance both depth range and field of view (FOV). By implementing a dual-wavelength method, we achieved a maximum expected depth range of 7.7 µm. The amplified phase due to the dual-wavelength approach was effectively mitigated by utilizing the configuration of successive accumulation of interferograms. In addition, the error correction algorithms further enhanced image quality, yielding a precision of 1.30 nm. Furthermore, we employed sophisticated image stitching techniques to attain a FOV of approximately 11 × 11 mm². This system enabled us to perform precise, wide-area inspections of hole structures fabricated on a silicon wafer, demonstrating its efficacy and potential for high-resolution, large-scale industrial applications.