晶圆对心转台亚微米级径跳误差补偿方法

Submicron Radial Runout Error Compensation Method for the Turntable in a Wafer Prealigner

为了消除转台径跳误差对晶圆预对准台重复性定位精度的影响,提出径跳误差的在线检测与补偿方法。转台上方并与之一起旋转的心轴作为转台径跳的检测元件,电涡流传感器测量心轴径向距离,其测量值由固定误差和径跳误差组成,借助集合平均法或者转台径跳特性,离线求解固定误差,据此在线工作时从电涡流传感器数据中分离出径跳误差。利用该误差对激光位移传感器检测的晶圆边缘数据进行径跳误差补偿,分析误差特性,据此简化补偿算法。试验证明,径跳误差补偿方法的使用提高了系统的预对准精度,并最终使系统达到了微米级的定位精度要求。

In order to eliminate the influence of the radial runout error of the turntable on the prealignment precision of a wafer prealigner, an on-line detection and compensation method for the error is proposed. The mandrel above and rotating along with the turntable is taken as the detecting component of the radial runout, and the radial distance of the mandrel is detected by a vortex sensor. The sensor＇s measurement value consists of fixed error and radial runout error, the former is solved off-line by means of ensemble average method or radial runout features of the turntable, based on which the radial runout error is separated from the data of the vortex sensor when working on-line. The radial runout error is used to compensate the peripheral data of the wafer detected by a laser displacement sensor with the compensation method simplified according to the error features. The experimentation has proved that the use of the radial runout compensation method has improved the prealignment precision of the system and made it meet the requirement of micron positioning precision.