High Frequency Flux Sampling SQUID Microscope

ORAL

Abstract

One important application of scanning SQUID microscopes is to fault detection in integrated circuits and multi-chip modules. However, the present generation of computer processors operate at over 1 GHz, well above the bandwidth of the present generation of SQUID microscopes. We have overcome the bandwidth limitations of traditional scanning SQUID microscopes by removing the main bandwidth limiter -- the conventional flux-locked loop electronics -- and using instead a pulsed sampling technique with a hysteretic dc SQUID. We present time-varying magnetic field images obtained with the 4.2 K cryocooled microscope with a time-resolution below 1 nanosecond, and discuss the advantages and limitations of this method.

*Supported by CSR, Neocera, Inc. and LPS.

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Authors

  • C.P. Vlahacos

    • Laboratory for Physical Sciences and University of Maryland

  • J. Matthews

    • University of Maryland

  • S.P. Kwon

    • University of Maryland

  • F.C. Wellstood

    • University of Maryland
    • Center for Superconductivity Research and Joint Quantum Institute, Department of Physics, University of Maryland