Diagnostics and failure analysis of integrated circuits, like any other facet of the semiconductor industry, has to continuously improve to remain viable. The long-term trend toward more complex, faster, denser devices with smaller features and more layers makes many conventional IC diagnostic techniques obsolete. For example, mechanical or e-beam probing find very limited use in diagnostics of modern microprocessors since the dense multi-level interconnecting wires cover the nodes of interest. For flip-chip packaged ICs these techniques are not applicable at all.

In my talk I present a new IC diagnostic technique based on the time-resolved photon emission microscopy - Picosecond Imaging Circuit Analysis (PICA). Invented at IBM, the technique is based on position- and time-resolved counting of single photons emitted by switching CMOS circuits.

I start with a description of the processes that lead to the light emission from modern transistors. I proceed with explaining how PICA uses single photons emitted from an IC to reconstruct its operation and present examples of practical uses of PICA to debug latest IBM microprocessors. I conclude my talk with the analysis of PICA applicability to future CMOS generations and its prospects for coming post-CMOS era.