双极大功率晶体管背面工艺优化

Back Process Optimization of the Bipolar Power Transistor

针对双极大功率晶体管批量生产时,存在的晶体管基极-集电极(BC)之间正向压降偏大且一致性较差的现象,对影响功率晶体管BC正向压降的因素进行了分析,并进行了相应的工艺实验,优化了工艺条件。实验结果表明,影响功率晶体管BC结正向压降的是背面减薄工艺和背面金属化工艺前的清洗工艺,芯片背表面的状态是影响器件BC正向压降的主要因素,优化后功率晶体管的BC正向压降优于指标要求,提高了批次间芯片参数的一致性,确保了双极大功率晶体管的工作稳定性。

With in the phenomenon that the base-collector （BC） forward voltage drop was high and the consistency was poor during bipolar power transistor mass production, the influence factors on the BC forward voltage drop of the bipolar power transistor were analyzed, and the process experiment was carried out accordingly, the process conditions were optimized. The experimental resuhs show that the back thinning process and the cleaning process before the back metallization process are affecting the BC forward voltage drop, the chip back surface conditions are the main factors. The optimized power transistors BC forward voltage drop is better than the index requirements, and the chip parameters uniformity is improved between the batch, the working stability of the bipolar power transistor is ensured.