Determination of Electrically Active Defect Profiles in Semiconductors Using a Photoelectrochemical Technique

Abstract

ABSTRACT Electrically active defects are common in semiconductors. Such defects include easily ionized substitutional impurities, vacancies, and interstitials which can act as shallow donors or acceptors. If one type of defect predominates, its concentration corresponds directly to the local donor or acceptor concentration. Consequently, measurement of a carrier profile in a nonhomogeneous semiconductor is effectively the same as measurement of the defect profile. The photoelectrochemical profiling technique allows for carrier profile measurement with submicrometer spatial resolution. The sample is profiled by photoetching, then carrier measurement, and iterating this procedure until the desired profile depth is obtained. Derivation of the space charge capacitance by impedance spectroscopy is discussed. An analysis of the P-doped Si-liquid electrolyte interface is presented. Phosphorous diffusivity coefficients in good agreement with literature values are derived from photoelectrochemical derived profiles.

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Identifiers

DOI

10.1557/proc-82-151

Journal

MRS Proceedings

Year

1986