Effect of Metallurgical Structure on Electrical Resistivity of Metallurgic Multicrystalline Silicon

Using a four point resistivity test system,metallographic microscopy,scanning electron microscopy (SEM),inductively-coupled plasma spectrometer (ICP),energy dispersive X-ray spectrometel (EDS) etc.,the influence of grain size,microstructure,chemical composition,precipitation in grain boundaries etc.on electrical properties of multicrystalline silicon prepared by metallurgic method was investigated.The electrical resistivity is directly propotional to the grain size when the microstructure was equiaxied grains.When it columnar grains,the electrical resistivity in the direction parallel to the columnar crystal is higher than at vertical to the grains.In the low-purity multicrystalline silicon,the metal impurity is easy to segregate in grain boundaries,forming phase of metal silicides and making the electrical resistivity of the multicrystalline silicon lower.