METHOD OF RENDERING INHOMOGENEITIES OF A FLAT SEMICONDUCTOR SURFACE IN TERAHERTZ RADIATION Russian patent published in 2020 - IPC G01B11/30 G01N21/88 

FIELD: optical quality control methods.

SUBSTANCE: invention relates to optical methods for controlling quality of semiconductor and metal articles surface, in which interaction of probing radiation with surface is mediated by surface electromagnetic wave (SEW) excited by incident radiation and directed surface. Disclosed method of viewing inhomogeneities of a flat semiconductor surface in terahertz radiation involves exposing a surface to p-polarized radiation, for which the real part of dielectric permittivity of the semiconductor is negative, conversion of radiation to surface-directed surface plasmon-polaritons (SPP) and measurement of radiation intensity emitted from SPP track. Radiation is selected monochromatic with frequency, at which SPP propagation length does not exceed emission wavelength, probing radiation beam is collimated and directed at an SPP generation angle to the base of the disturbed total internal reflection prism, which faces the controlled surface area and is placed parallel to it within the SPP field penetration depth into the environment. Spatial distribution of radiation intensity is recorded simultaneously over the entire cross section of the beam emerging from the prism.

EFFECT: method of rendering inhomogeneities of a flat surface of a semiconductor in a terahertz radiation based on conversion of probing radiation to surface plasmon-polaritons (SPP) directed by a controlled surface, and detection of radiation emitted from SPP track due to preservation of their optical communication with conversion element, and allowing to simplify measurement procedure, reduce its labor input and duration, as well as increase lateral resolution of measurements.

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