碳化硅晶片减薄工艺对表面损伤的影响

Effect of SiC Wafer Grinding Process on Surface Damage

随着碳化硅功率器件和芯片技术的快速发展,对碳化硅物理强度、散热性及尺寸要求越来越高,因而,对碳化硅晶片的减薄处理逐渐成为晶圆加工的重要课题。由于碳化硅材料断裂韧性较低,在减薄加工过程中易开裂,碳化硅晶片的高效率、高质量加工成为急需突破的瓶颈。本文基于碳化硅晶片的磨削减薄工艺技术,从加工过程及基础原理出发,通过研究磨削减薄工艺中四个主要参数(砂轮粒度、砂轮进给率、砂轮转速和工作台转速)对晶片表面的损伤,如崩边和磨痕的影响,提出前退火减薄工艺,以提高晶片加工质量,降低晶片表面损伤。本研究工作揭示了晶片减薄工艺技术调控表面质量的方法,并在实验加工过程中验证成功,相关研究结果对加工难度大的硬脆材料晶片减薄技术具有重要的指导意义。

With the rapid development of silicon carbide(SiC)power devices and chip technology,the demand for grinding process of SiC wafers has become increasingly crucial due to the escalating requirements for physical strength,heat dissipation and size.Therefore,grinding process of SiC wafers has gradually become an important issue in manuscription processing.Due to its low fracture toughness,the SiC wafers are prone to cracking during grinding processes.It’s a big challenge in achieving an efficient and high-quality grinding process for SiC wafers.Based on the process and principle analysis of SiC wafer grinding,the influence of four key parameters in the grinding process,i.e.,grinding wheel size,feed rate,grinding wheel speed and chuck table speed on wafer surface edge breakage,were studied in this paper.The process of improving the processability of wafer by annealing is presented,and the surface integrity improving process of wafer is proposed.The study reveals the control method of wafer grinding processing surface quality,offered an efficient process route for reducing surface damage and improving the surface layer quality of chips,and verified the machining effect through experiments.The relevant results have important guiding significance for the wafer grinding process of hard and brittle materials.