New wafer prealigner based on multi-sensor fusion

Aiming to traditional pre-alignerspsila deficiencies in the precision of prealignment and spacing consuming in the manufacture of integrated circuits, a new wafer prealigner was proposed, which uses a high-precision laser displacement sensor and a low-cost transmission laser sensor as wafer-periphery detectors instead of a CCD linear sensor traditionally used, and correspondingly a precise prealignment algorithm was developed based on the multi-sensor fusion. The eccentricities of the wafer and the notch were calculated by means of centroid acquiring algorithm among one particle system, the micron-rank prealignment precision was achieved at the end. The proposed system has saved the space occupation of the structure and enhanced the systematic prealignment precision. Experimentation has proved the validity and effectiveness of the system.