硼硅酸盐玻璃晶片激光标识的制作技术

Laser mark technology for borosilicate glass wafer

晶片标识码的手写方式存在不美观、字体边缘玻璃蹦渣及划痕深等缺点。某些MEMS工艺玻璃-Si键合片需KOH腐蚀。采用手写,KOH通过玻璃片标码部位侵入晶片正面而腐蚀器件结构。因此,采用波长10640 nm CO2激光器针对玻璃晶片进行激光标识制作的打标工艺。研究中分别改变激光平均输出功率、脉冲频率及扫描速度,借助目视、金相显微镜及动态三维光学轮廓仪来观察标识码的清晰度、是否产生裂纹及字体凸起程度,了解它们与上述参数间相互对应关系。重点解决清晰度与凸起高度的矛盾,从而得到清晰、无裂纹且凸起高度满足后续半导体纳米级加工工艺要求的激光标码技术。结果表明:脉冲频率对清晰度、裂纹产生及凸起高度无显著影响;平均功率与清晰度及凸起程度呈正比例关系,与裂纹产生无相关性;扫描速度与清晰度、裂纹产生的可能性及凸起高度呈反比关系。采用40%平均功率,20 k Hz频率,150 mm/s扫描速度及单线字体(JCZ Single Line)进行标刻时,标识码在目视及镜检下清晰可视,无微细裂纹,轮廓仪测量结果显示字迹凸起高度为185 nm。应用上述条件标码的玻璃片与Si键合并在KOH中腐蚀5 h后无KOH进入晶片正面的现象发生。

Wafer mark is very important on both process management side and wafer history track.Glass wafer used for R＆D lab does not have mark before process.Some labs make mark by using diamond material manually,and this will have disadvantages such as crack and excess mark depth,which affect the following process step.The glass wafer was marked by using 1 0640 nm CO2 laser.During the work,the effect of laser average power,pulse frequency and scan speed on mark definition was studied,and crack and mark height were observed by eye inspection,metalloscope and 3D optical profiler.The results show that the effect of pulse frequency on mark definition,crack and mark height is not obvious;the average power is proportional to mark definition and mark height,and is irrelevant to crack;scan speed is inversely proportional to make definition,crack and mark height.Under the condition of 40% average laser power,20 kHz pulse frequency and 1 50 mm/s scan speed,there are clear definition,non-crack and 1 85 nm in height glass wafer mark.The overall result shows that the proposed method is robust.