Xiangfu Liu, Minghui Hong
Opt Express. 2024 Oct 21;32(22):38758-38767. doi: 10.1364/OE.540604.
Low kerf-loss and high surface quality silicon carbide (SiC) wafer slicing is key to reducing cost, improving productivity, and extending industrial applications. In this paper, a novel all-laser processing approach is proposed by combining laser micro-cracks generation and growth manipulation. The first high fluence pulsed laser is applied to generate micro-cracks inside SiC, which increases its laser energy absorption. The second low fluence pulsed laser achieves the manipulation of micro-cracks growth and interconnection to separate SiC wafer. The optimal laser processing parameters are obtained to separate a 4H-SiC substrate at a thickness of 500 µm. The sliced surface is clean with average surface roughness (Sa) of 186 nm, standard deviation of 0.037, and kerf-loss of 915 nm. This laser slicing approach can be applied for high-hardness transparent material separation.
低切口损失和高表面质量的碳化硅（SiC）晶圆切割是降低成本、提高生产率和扩展工业应用的关键。本文提出了一种通过结合激光微裂纹产生和生长控制的新型全激光加工方法。首先使用高能量密度脉冲激光在SiC内部产生微裂纹，这增加了其激光能量吸收。然后使用低能量密度脉冲激光实现微裂纹生长和互连的控制，以分离SiC晶圆。获得了用于分离厚度为500 µm的4H-SiC衬底的最佳激光加工参数。切割后的表面干净，平均表面粗糙度（Sa）为186 nm，标准偏差为0.037，切口损失为915 nm。这种激光切割方法可用于高硬度透明材料的分离。
