Characterization of structural defects in the silicon crystal grown with various seeds

To see the effect of the seeds on the crystallization of the silicon ingot, two types of seed were prepared and applied to the mono-like multi-crystalline silicon crystallization. One of them was conical shaped seed divided vertically into 4 pieces and the other one was chipped silicon seeds. Both of the seeds were placed at the bottom of the crucible before the growth of the multi-crystalline silicon material with a conventional directional solidification process. Compared to the conventional thin and flat seeds, conical shaped seed result in the larger single crystalline portion in the ingot although the gap of the seed division might act as source of dislocation generation during the crystal growth. This was expected to be due to the lateral growth of the silicon single crystalline grown from the conical seed which is taller than normal flat seeds. And also, comparison of the Minority Carrier Life Time (MCLT) between the silicon crystal grown from the chipped silicon seeds and the silicon crystal grown without any seed was conducted. It was found that the silicon crystal grown with chipped silicon seeds shows higher MCLT than the silicon crystal grown without seeds, although both crystals look similar as multi-crystalline silicon.