Cheng Zhihao, Luo Qiufa, Lu Jing, Tian Zige
Institute of Manufacturing Engineering, Huaqiao University, Xiamen 361021, China.
National & Local Joint Engineering Research Center for Intelligent Manufacturing Technology of Brittle Material Products, Xiamen 361021, China.
Micromachines (Basel). 2022 Jun 11;13(6):930. doi: 10.3390/mi13060930.
Microcracks inevitably appear on the SiC wafer surface during conventional thinning. It is generally believed that the damage-free surfaces obtained during chemical reactions are an effective means of inhibiting and eliminating microcracks. In our previous study, we found that SiC reacted with water (SiC-water reaction) to obtain a smooth surface. In this study, we analyzed the interfacial interaction mechanisms between a 4H-SiC wafer surface (0001-) and diamond indenter during nanoscale scratching using distilled water and without using an acid-base etching solution. To this end, experiments and ReaxFF reactive molecular dynamics simulations were performed. The results showed that amorphous SiO was generated on the SiC surface under the repeated mechanical action of the diamond abrasive indenter during the nanoscale scratching process. The SiC-water reaction was mainly dependent on the load and contact state when the removal size of SiC was controlled at the nanoscale and the removal mode was controlled at the plastic stage, which was not significantly affected by temperature and speed. Therefore, the reaction between water and SiC on the wafer surface could be controlled by effectively regulating the load, speed, and contact area. Microcracks can be avoided, and damage-free thinning of SiC wafers can be achieved by controlling the SiC-water reaction on the SiC wafer surface.
在传统减薄过程中，SiC晶圆表面不可避免地会出现微裂纹。人们普遍认为，化学反应过程中获得的无损伤表面是抑制和消除微裂纹的有效手段。在我们之前的研究中，我们发现SiC与水发生反应（SiC-水反应）可获得光滑表面。在本研究中，我们分析了在纳米尺度划痕过程中，4H-SiC晶圆表面（0001-）与金刚石压头之间在使用蒸馏水且不使用酸碱蚀刻溶液的情况下的界面相互作用机制。为此，进行了实验和ReaxFF反应分子动力学模拟。结果表明，在纳米尺度划痕过程中，在金刚石磨料压头的反复机械作用下，SiC表面生成了非晶态SiO。当SiC的去除尺寸控制在纳米尺度且去除模式控制在塑性阶段时，SiC-水反应主要取决于载荷和接触状态，而受温度和速度的影响不显著。因此，通过有效调节载荷、速度和接触面积，可以控制晶圆表面水与SiC之间的反应。通过控制SiC晶圆表面的SiC-水反应，可以避免微裂纹，并实现SiC晶圆的无损伤减薄。
