Investigation of defects and striations in as-grown Si crystals by SEM using Schottky diodes

As-grown silicon crystals are investigated in the scanning electron microscope using Schottky barrier diodes in the electron-beam-induced current mode. Dislocations, A- and B-type swirl defects, as well as dopant striations are detected. In high-resistivity crystals (∼1000 Ω cm) variations in dopant concentration of 1012 cm−3 are readily revealed. Hydrogen doping is found to eliminate preferential recombination at microdefects. It is established that bulk stresses due to carbon striations have no detectable electrical effect.