晶圆预对准精确定位算法

A method of precise orientation of wafer prealignment

针对IC制造工艺中传统的晶圆预对准控制系统预对准精度不高和占用空间较大的不足,提出了一种采用高精度激光位移传感器和低成本的透射式激光传感器的新型晶圆预对准系统,并结合该系统的特点提出了相应的晶圆预对准精确对位算法,而且进行了晶圆预对准重复性精度检测和实验验证.该系统用两种传感器数据融合的方式来检测晶圆的边缘,用质点系重心法确定晶圆形心和缺口位置,最终实现了微米级的晶圆预对准.该系统提高了对准算法的精度,减小了预对准台占用的实际空间,降低了成本.实验结果验证了该系统的有效性.

Aiming to traditional wafer prealingers＇ deficiencies in the precision of prealignment and spacing consuming in the manufacture of integrated circuits, a new wafer prealigner was proposed using a high-precision laser displacement sensor and a low-cost transmission laser sensor as detectors, and correspondingly a precise prealignment algorithm was developed based on the features of the system, and the experiment of prealignment precision testing was performed. The periphery of the wafer was detected by means of the two sensors＇ integration, the eccentricity of the wafer and the orientation of the notch were calculated by means of byracenter acquiring algorithm among one particle system, the micron-rank prealign- ment precision was achieved at the end. The proposed system has enhanced the precision of prealignment, saved the occupation of the space and decreased the cost. Experimentation has proved the validity and effectiveness of the system.