Delineation of crystalline extended defects on multicrystalline silicon wafers

We have selected Secco and Yang etch solutions for the crystalline defect delineation on multicrystalline silicon (mc-Si) wafers. Following experimentations and optimization of Yang and Secco etching process parameters, we have successfully revealed crystalline extended defects on mc-Si surfaces. A specific delineation process with successive application of Yang and Secco agent on the same sample has proved the increased sensitivity of Secco etch to crystalline extended defects in mc-Si materials. The exploration of delineated mc-Si surfaces indicated that strong dislocation densities are localized mainly close to the grain boundaries and on the level of small grains in size (below 1 mm). Locally, we have observed the formation of several parallel dislocation lines, perpendicular to the grain boundaries. The overlapping of several dislocations lines has revealed particular forms for etched pits of dislocations. Copyright (C) 2007 Mohamed Fathi.