Study Of Micromagnetic Detection And Imaging Technology For The Crystalline Silicon

Crystalline silicon is a key base material of the electronic information industryand the solar photovoltaic industry.Various crystalline defects and processing defectspresent in the semiconductor wafer, have different degrees of impact of the electricdevice quality and yield. The current methods of detection of defects of crystallinesilicon, such as ultrasound, infrared, and analysis for individual elements,etc,thesemethods have many problems, they cannot be applied to industrial processes. Thisstudy proposes a method based on micromagnetic detection in the geomagnetic fieldto detect traces of carbon impurity defects and micro-cracks and other defects in thecrystalline silicon.The magnetization tests show that silicon is a diamagnetic substance with astronger relative permeability than carbon. The abnormal features in the magneticfield where the defects exist were analyzed based on differences in relativepermeability. Mechanism analysis the feasibility of the micromagnetic detection fortrace impurities and micro-cracks and other defects in the crystalline silicon.Throughthe polysilicon sheet and ingot micro-magnetic detection experiments and analysis ofexperimental results.Comparisons between the metallographic phase and spectralanalysis proved that the method adopted in this study is feasible and effectivelydetects traces of carbon impurity defects and micro-cracks and other defects incrystalline silicon.In order to meet the requirements of the silicon sheet and siliconingot industrialized production process defect detection, developed a set ofcrystalline silicon automatic defect detection system, The system is mainlycomposed by the array of magnetic micro-magnetic detector, mechanicaltransmission device and the host computer software. According to the characteristicsof micro-magnetic detection signal, the least squares smoothing method was putforward to smooth the detection signal digital.According to the energy decay, whenthe geomagnetic field penetrates through the materials, the apparent magneticsusceptibility can be calculated and subsequently used to project the images. Theresulting image clearly showed the location of the defects. This article provides newmethods and ideas for effective detection of trace impurities and micro-cracks andother defects in the crystalline silicon.