METHOD OF PROFILING COMPOSITION AT EPITAXIAL FORMATION OF SEMICONDUCTOR STRUCTURE BASED ON SOLID SOLUTIONS

摘要

FIELD: technological processes.;SUBSTANCE: invention relates to profiling of composition of solid solutions of heteroepitaxial structures at their growth. Method of forming a structure of type A₂B₆ based on tellurides of the elements of the second group of the Periodic Table involves measuring ellipsometric parameters Ψ and Δ at one wavelength of light in the visible region of the spectrum. Prior to measurements carried out with respect to the structure, the profile of which is obtained by means of ellipsometry, the growth rate of the structure is determined. When performing measurements with respect to a structure whose profile is obtained, a time interval of measurements is set, based on the growth rate, at which the thickness of the layer grown during the time interval between the j-th and (j+1)-th measurements, with constant its composition and optical properties is equal to value from 0.2 to 1.5 nm, including specified values. Then, with error of not more than 0.01° and with angle of incidence of light ϕ with value in range from 65 to 70° measurements of ellipsometric parameters Ψ_j and Δ_j, fixing measurement time t_j. After measurements, as a result of which the data array {t_j, Ψ_j, Δ_j} is obtained, where j = 1, 2, …m is the serial number of the measurement, m is the total number of measurements, using the results of determining growth rate and measuring ellipsometric parameters Ψ and Δ during growth, direct calculation of optical constant layers formed during time intervals between each two successive measurements. Composition of each layer is directly calculated between two said measurements, coordinates of layers are determined and distribution profile of composition over the thickness of structure is obtained.;EFFECT: high accuracy of determining the distribution profile of the composition – the molar component of the solid solution x, varying from 0 to 1, over the thickness of the formed structure, until spatial resolution of the nanometer scale is achieved, both in thickness and composition, directly during growth; possibility of obtaining profile distribution of composition over thickness from any moment during formation of structure.;3 cl, 6 dwg, 3 ex