FAILURE ANALYSIS OF INTEGRATED CIRCUITS USING OPTICAL THERMOGRAPHY AND SPECTROREFLECTANCE MICROSCOPY

remote microscopy We demonstrate failure analysis of integrated circuits (IC) at optical resolution ( ~ 1 µm) using an optical feedback laser diode confocal microscope. By acquiring the reflectance and the optical-beam-induced current (OBIC) images at each point on the sample, it is possible to discriminate the semiconductor from the metallic sites in integrated circuits[1]. Such spatial classification reveals the nature of defect and probable cause of failure. Differential thermal maps[2] of semiconductor are derived by detecting changes in the OBIC signal that are produced in the active layer in response to variations in the IC package temperature. The thermal maps show locations of high thermal activity in the active layer including anomalous regions where the OBIC outputs decrease with increasing temperature. These anomalous regions are loci of accumulating semiconductor electrical resistance and provide the best jump-off points for efficient and accurate IC fault analysis procedure. Aside from absorption, reflectance can also yield thermal information about the IC. We construct a versatile and cost-effective spectral microscope for generating spectral reflectance maps that distinguish subtle differences in performance among various semiconducto