Wang Heng, Cao Qiang, Hou Yuting, Yu Lulu, Wu Tianhao, Wang Zhenzhong, Wang Du
The Institute of Technological Sciences, Wuhan University, Wuhan 430072, China.
Shandong Engineering Research Center of New Optoelectronic Information Technology and Devices, School of Mathematics and Physics, Qingdao University of Science & Technology, Qingdao 266061, China.
Micromachines (Basel). 2025 Aug 13;16(8):930. doi: 10.3390/mi16080930.
Silicon carbide (SiC), a wide-bandgap semiconductor, is renowned for its exceptional performance in power electronics and extreme-temperature environments. However, precision low-loss laser slicing of SiC is impeded by energy divergence and crack delamination induced by refractive-index-mismatch interfacial aberrations. This study presents an integrated laser slicing system based on a liquid crystal on silicon spatial light modulator (LCOS-SLM) to address aberration-induced focal elongation and energy inhomogeneity. Through dynamic modulation of the laser wavefront via an inverse ray-tracing algorithm, the system corrects spherical aberrations from refractive index mismatch, thus achieving precise energy concentration at wanted depths. A laser power attenuation model based on interface reflection and the Lambert-Beer law is established to calculate the required laser power at varying processing depths. Experimental results demonstrate that aberration correction reduces focal depth to approximately one-third (from 45 μm to 15 μm) and enhances energy concentration, eliminating multi-layer damage and increasing crack propagation length. Post-correction critical power measurements across depths are consistent with model predictions, with maximum error decreasing from >50% to 8.4%. Verification on a 6-inch N-type SiC ingot shows 90 μm damage thickness, confirming system feasibility for SiC laser slicing. The integrated aberration-correction approach provides a novel solution for high-precision SiC substrate processing.
碳化硅（SiC）作为一种宽带隙半导体，因其在功率电子学和极端温度环境中的卓越性能而闻名。然而，SiC的精密低损耗激光切片受到折射率失配界面像差引起的能量发散和裂纹分层的阻碍。本研究提出了一种基于硅基液晶空间光调制器（LCOS-SLM）的集成激光切片系统，以解决像差引起的焦伸长和能量不均匀问题。通过逆光线追踪算法对激光波前进行动态调制，该系统校正了折射率失配引起的球差，从而在所需深度实现了精确的能量集中。建立了基于界面反射和朗伯-比尔定律的激光功率衰减模型，以计算不同加工深度所需的激光功率。实验结果表明，像差校正将焦深减小到约三分之一（从45μm减小到15μm），并提高了能量集中度，消除了多层损伤，增加了裂纹扩展长度。校正后不同深度的临界功率测量结果与模型预测一致，最大误差从>50%降至8.4%。在6英寸N型SiC晶锭上的验证显示损伤厚度为90μm，证实了该系统用于SiC激光切片的可行性。这种集成像差校正方法为高精度SiC衬底加工提供了一种新的解决方案。
