A Fast Acquisition System for Large-Scale Optical Microscopic Integrated Circuit Chip Images Based on Thin Plate Spline

When large-scale images acquisition conducted on an Integrated Circuit (IC) chip by using an optical microscope, multi-layer routing structure and transparent inter-layer dielectric of IC chips can interfere with auto-focusing of an optical microscope, which significantly increases the images’ acquisition time. To solve the forementioned problems, a fast acquisition system is proposed based on surface fitting. First of all, we obtain focus plane height of multiple scattered points through pre-acquisition. Then, the surface fitting method, with Thin Plate Spline (TPS) model is applied, to get the height of the rest points. Thus the system can acquire correct surface-layer images of an IC chip without background interference. The experimental results suggest that the proposed technology is highly superior to manual acquisition system and auto-focusing based acquisition system in acquisition accuracy and speed, and it also decreases the amount of manual workload by 70%-80%.

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