METHOD OF MEASUREMENT OF PARAMETERS OF SEMICONDUCTOR MATERIALS

FIELD: electronics. SUBSTANCE: semiconductor is irradiated by probing electromagnetic radiation which wave length is bigger than thickness of examined layer of semiconductor. Intensity of interference maxima of first or second order of reflected or passed-through signal is measured. Simultaneously with irradiation examined surface of sample is brought to contact with two resistively uncoupled regions of liquid electrolyte chemically neutral to material of sample. Constant voltage impoverishing layer of sample close to contact with charge carriers and alternating voltage are applied. Capacitance of impoverished layer is measured and its depth is determined. After this dependence of power of electromagnetic radiation absorbed in layer of examined part of sample non-impoverished by charge carriers on value of alternating voltage is plotted and by this dependence mobility of charge carriers on boundary of impoverished layer is calculated and by change of value of absorbed power of radiation in conductive layer with two adjacent values of depth of impoverished layer specific conductance is computed as well as concentration of charge carriers. Repeating these operations at higher values of impoverishing voltage till entire conductive layer of sample is subjected to impoverishment or till electric break-through of region of transport of spatial charge one calculates dependences of specific conductance, concentrations of charge carriers in sample and local conductance on depth of mobility. To raise locality of measurements substance which electrolytically dissociates under optic radiation is used as electrolyte. In this case constant impoverishing and alternating voltages are fed to formed conductive region with the aid of lattice of metal grids located in this substance which last pass excitation and probing radiations and has window which dimension does not exceed size of region of electrolytic dissociation. EFFECT: improved authenticity of measurements. 2 cl, 4 dwg Изобретение относится к области контроля параметров полупроводниковых структур после технологических операций. Полупроводник облучают зондируюшим электромагнитным излучением, длина волны которого больше толщины исследуемого слоя полупроводника, измеряют интенсивность интерференционных максимумов I или II порядков отраженного или прошедшего сигнала, одновременно с облучением исследуемую поверхность образца приводят в контакт с двумя гальванически несвязанными областями химически нейтрального по отноше