The importance of the excitation volume in determination of surface recombination velocity

A Simple approach for evaluating the electron-beam induced current (EBIC) response of a grain boundary in polycrystalline silicon demonstrates that the response is composed of two different responses. At distances greater than two excitation-volume radii from the grain boundary, the response yields an effective surface recombination velocity within about ten percent of that obtained by fitting the data to the theoretical response for a point-source excitation. However, at distance less than two excitation-volume radii, the grain-boundary response is demonstrated to be the response to a skewed Gaussian excitation. This exemplifies the limitations of spacial resolution of an electron probe and the importance of quantitative measurements in determining the effective surface recombination velocity of internal and external surfaces of semiconducting regions.