Optical measuring arrangement for fast, contactless and non-destructive of characteristic semiconductor parameters

摘要

The invention relates to an optical measuring arrangement for fast, contactless and non-destructive determination of both characteristic electrical semiconductor parameters such as charge-carrier concentration, charge-carrier mobility and electrical conductivity, and the stoichiometry of specific ternary and quaternary compound semiconductors. The determination of the semiconductor parameters is carried out by recording and evaluating the reflection spectra in the infrared (IR) spectral range in the region of the plasma resonances and phonon oscillations of the semiconductor materials to be examined. Analysis of plasma resonance provides, according to the Drude model, charge-carrier concentration and mobility, and analysis of the phonon oscillations by means of Lorentzian oscillator functions gives information regarding the stoichiometry of specific ternary and quaternary compound semiconductors. According to the invention, fast and contactless measurement of the IR reflection spectra is achieved by the use of an optical measuring arrangement having suitable IR array detectors. The measurement method is suitable for use both in analysis of semiconductor bulk materials and for solid-state structures formed by layer systems, in which one or more involved crystalline phases are formed from the semiconductor materials to be characterised. The invention can be applied to amorphous, polycrystalline and monocrystalline semiconductor materials.