Developing of laser cutting and simultaneous removing of heat affected layer method of silicon, sapphile and SiC

本文对激光刻槽技术进行了研究，旨在将激光刻槽技术应用于半导体模具切割。对硅上形成的沟槽的分析表明，在液体腐蚀剂中加工比在空气或纯水中加工更有效地减少沟槽上的热影响层。此外，使用高重复频率和低峰值功率的激光器，可以获得比低重复频率和高峰值功率的激光更小的沟槽宽度；但是，过高的重复频率会造成沟槽周围的意外刻蚀。然而，这种无意的蚀刻可以通过液体腐蚀剂的循环来抑制。除了上述有关硅的事实外，还发现在含有强氧化剂的液体中处理可以有效地去除4H-碳化硅。

Laser grooving was performed in this study, aiming for its application to semiconductor-die cutting. Analysis of grooves formed on silicon revealed that processing in liquid etchants is more effective for reducing the heat affected layer on the grooves than processing in air or pure water. Besides, using a high-repetition-rate and low-peak-power laser, lower groove width was achieved than a low-repetition-rate and high-peak-power laser; however, excess repetition-rate caused unintended etching around the grooves. Though, such unintended etching could be suppressed by circulating the liquid etchant. In addition to above facts about silicon, it is found that 4H-SiC can be removed effectively by processing in liquid containing strong oxidant.