SiC微粉粒径对干法背面软损伤工艺影响

Effect of SiC Grain Size on Dry-method Backside Soft Damage for Silicon Wafers

以SiC微粉为媒介对硅晶片进行干法背面软损伤,而后对晶片进行抛光清洗及热处理。以制备的抛光片表面颗粒度、氧化雾和氧化诱生堆垛层错为评价指标,研究了不同粒径的SiC微粉对干法背面软损伤工艺的影响。实验结果表明,SiC微粉粒径对干法背面软损伤影响显著,当以粒径为6.7μm的SiC微粉对硅晶片进行干法背面软损伤时,制备的抛光片正表面洁净度良好,表面颗粒度为29个/片(表面颗粒D≥0.2μm)。经氧化诱生后,晶片背表面氧化诱生堆垛层错密度为(4~5)×10~4个/cm^2。背面软损伤层可起到较好的吸杂作用,经氧化诱生后晶片正表面无热氧化雾出现。

SiC grains are used to make backside soft damage（BSD） on silicon wafers by dry method. Then these wafers are treated with polishing, cleaning and thermal treatment. In order to investigate how SiC grain size influences the dry-method BSD process, the surface quality, haze of the polished wafers and oxidation-induced stacking faults（OISF） after thermal-treatment are studied respectively. The results show that SiC grain size has a significant effect on dry-method BSD process, the optimal SiC grain size is 6.7 μm. The count of particles（≥0.2 μm） on the polishing wafer is 29, the OISF density on the backside is（4~5）×10~4/cm^2. The backside damage can getter the impurity on the front side of silicon wafer, thus no haze appears on the front side of the wafer.