STP712: A Contactless Method of p-n Junction Leakage Testing and Comparison of Associated Data with Contact-Determined Leakage

    Verkuil, RL
    Advisory engineers, IBM Data Systems Division, Hopewell Junction, N.Y.

    Pak, MS
    Advisory engineers, IBM Data Systems Division, Hopewell Junction, N.Y.

    Pages: 14    Published: Jan 1980


    A contactless p-n junction leakage measurement method is described, which uses specialized very-high-frequency oscillator circuitry. This circuitry utilizes the eddy current loading effect, via inductive coupling, in order to determine the leakage-dependent decay time of the photoinduced voltage across the diffused p-n junctions in a silicon wafer.

    The contactless measurement is made under low forward bias conditions (≤ 10 mV), in such a way that this measurement and the contacting reverse leakage, measured at 100 mV, will both be functions of generation-recombination processes in the junction depletion region. Detectable signals were made possible by low-noise circuitry and by the increase in junction eddy currents from induced voltages across the diffused regions.

    The following model was derived from basic circuit theory, which relates the contactless decay time measurement, τ, to the conventional contacting reverse leakage, J0 J0=CkT


    J0 = reverse leakage, A/cm2,

    C = junction capacitance, F/cm2,

    τ = decay time, s, and

    kT/q = 26 mV at T = 300 K.

    Good agreement was obtained between experiment and theory. The examined range was four orders of magnitude in leakage current.


    semiconductor , p-n, junction leakage, contactless measurement, inductive coupling, eddy current, semiconductor photocell, semiconductor photoconductivity, silicon

    Paper ID: STP35140S

    Committee/Subcommittee: F01.19

    DOI: 10.1520/STP35140S

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