Cathodoluminescence defectoscopy of ZnS and ZnSe crystals

The quality and reliability of microelectronic materials can be dramatically changed by point and linear defects, which occur in specimens naturally, or which can be deliberately introduced. The control of defect distribution requires a measurement method capable of investigating the defects on a micrometer scale. This article surveys some of the opportunities for the control of defects in solids by using a combination of different cathodoluminescence modes including color cathodoluminescence (CCL) in the scanning electron microscope (SEM) with computer graphics. The method of cathodoluminescence defectoscopy was applied to microcharacterization of commercial wide-band-gap II–VI semiconductors (ZnS, ZnSe) as well as to the thin diffusion layers formed in these materials in the process of annealing. The luminescence topography of the radiative centres distribution at different Al and Bi concentrations was investigated and a model of two-polar and dissociative diffusion of Zn, Al and Bi from the melt to the crystal volume was proposed.