METHOD FOR CONTACT-FREE DETERMINATION OF LIFE SPAN FOR NON-EQUILIBRIUM CARRIERS IN SEMI-CONDUCTORS Russian patent published in 2012 - IPC H01L21/66 G01N21/41 

FIELD: electricity.

SUBSTANCE: method uses differential optical arrangement in which beam of probing laser is divided into two beams; one beam passes through the specimen point where measurement is made while the other beam passes through the point located at distance from the first point and this distance is much bigger than diffusion distance of charge carriers. Thereafter two beams are gathered at one pint where photoreceiver is located. In result of refractivity variation nearby specimen point where measurements are made path difference between these beams is lost. Due to interference changes occur in rate of radiation received by photoreceiver. Life span of charge carriers is determined by computational method based on calculation of refractivity variation of radiation received by photoreceiver and substituting known parameters of shortwave injected radiation.

EFFECT: use of such arrangement allows increase of method sensitivity five times approximately.

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