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Publications (2)0 Total impact

  • T. Eiles, G. Woods, V. Rao
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    ABSTRACT: With the growing number of IC interconnect layers and flip chip packaging, node access for signal probing from the frontside of the chip becomes practically impossible. Optical probing make it possible to directly probe p-n junctions that form the drains of MOS transistors in a CMOS IC, from the silicon side of the chip. The probe consists of a focused infrared laser that reaches the diffusions by propagating through the silicon substrate. The reflected beam acts as an optical carrier whose amplitude and phase is modulated by the waveform on the node being probed. Although the optical modulation is small, it can be recovered with a combination of low noise signal recovery and stroboscopic techniques. From the chip backside, there is no metallization in the way to obscure the transistor drains. Hence, every signal in the chip can be probed
    Solid-State Circuits Conference, 2000. Digest of Technical Papers. ISSCC. 2000 IEEE International; 02/2000
  • [show abstract] [hide abstract]
    ABSTRACT: A novel optical probing technique to measure voltage waveforms from flip-chip packaged CMOS integrated circuits (IC) is described. This IR laser based technique allows signal waveform acquisition and high frequency timing measurements directly from active P-N junctions through the silicon backside substrate on ICs mounted in flip-chip stand-alone or multi-chip module packages as well as wire-bond packages on which the chip backside is accessible. The technique significantly improves silicon debug and failure analysis (FA) throughput time (TPT) as compared to backside electron-beam (e-beam) probing because of the elimination of backside trenching and probe hole generation operations
    Physical and Failure Analysis of Integrated Circuits, 1999. Proceedings of the 1999 7th International Symposium on the; 02/1999