Two-step model versus one-step model of the inter-polarization conversion and statistics of CdSe/ZnSe quantum dot elongations

The magneto-optical inter-polarization conversions by a layer of quantum dots have been investigated. Various types of polarization response of the sample were observed as a function of external magnetic field and of the orientation of the sample. The full set of experimental dependences is analyzed in terms of a one-step and a two-step model of spin evolution. The angular distribution of the quantum dots over the directions of elongation in the plane of the sample is taken into account in terms of the two models, and the model predictions are compared with experimental observations

Characterization of stress in semiconductor wafers using birefringence measurements

The nondestructive optical method for quality control based on measurement of birefringence in semiconductor wafers is described. The influence of crystallographic orientation and multiple reflections in wafers on measured parameters are discussed. Also the full description of the device used for investigation of commercial semiconductor wafers is given. The last part of the article is devoted to the results of experimental investigations of semiconductor wafers during manufacturing of semiconductor devices and IC