基于普通F-Theta透镜与远心F-Theta透镜的晶圆标识工艺的研究

Study on the Processing of Wafer Marking Based on General F-Theta Lens and Telecentric F-Theta Lens

为研究聚焦系统对晶圆标识工艺的影响,搭建以1 066 nm的声光调Q脉冲光纤激光器为光源,分别使用普通F-Theta透镜和远心F-Theta透镜的晶圆激光打标系统,使用相同的工艺参数分别在晶圆表面进行点阵标识,研究两种聚焦系统下晶圆的烧蚀阈值、离焦效果和点的形貌。采用白光干涉仪对晶圆标识区域的三维形貌进行评估,研究发现普通F-Theta透镜与远心F-Theta透镜对晶圆的烧蚀阈值的影响区别不大。在离焦效果方面,普通F-Theta透镜随着离焦量增加,标识点直径逐渐变小;而远心F-Theta透镜随着离焦量增加,标识点直径先增大后减小。在打标范围内的标识质量方面,两者在打标范围中心的标识质量基本相当,离中心越远,远心透镜也未能表现出更好的标识形貌。

In order to study the influence of general F-Theta lens on telecentric F-Theta lens on wafer marking process, a wafer laser marking system using 1 066 nm acousto-optic Q-switched pulse fiber laser as light source and general F-Theta lens and telecentric F-Theta lens respectively is built. Dot matrix marking is carried out on the wafer surface with the same process parameters, and the ablation threshold, defocus effect and ablation plan of wafers under two F-Theta lenses are studied. Moreover, the three-dimensional morphology of wafer identification area is analyzed by white light interferometer. It is found that general F-Theta lens and telecentric F-Theta lens have little effect on the ablation threshold of wafers. In terms of defocusing effect, the ablation aperture of ordinary F-Theta lens decreases gradually with the increase of defocusing amount, while the ablation aperture of telecentric F-Theta lens first increases and then decreases with the increase of defocusing amount. In terms of the mark quality in the marking range, the mark quality of the two in the center of the marking range is basically the same, the farther away from the center, the telocentric lens does not show better mark morphology.