Temperature mapping of stacked silicon dies from x-ray diffraction intensities

Increasing power densities in integrated circuits has led to an increased prevalence of thermal hotspots in integrated circuits. Tracking these thermal hotspots is imperative to prevent circuit failures. In 3D integrated circuits, conventional surface techniques like infrared thermometry are unable to measure 3D temperature distribution and optical and magnetic resonance techniques are difficult to apply due to the presence of metals and large current densities. X-rays offer high penetration depth and can be used to probe 3D structures. We report a method utilizing the temperature dependence of x-rays diffraction intensity via the Debye-Waller factor to simultaneously map the temperature of an individual silicon die that is a part of a stack of dies. Utilizing beamline 1-ID-E at the Advanced Photon Source (Argonne), we demonstrate for each individual silicon die, a temperature resolution of 3 K, a spatial resolution of 100 um x 400 um and a temporal resolution of 20 s. Utilizing a sufficiently high intensity laboratory source, e.g., from a liquid anode source, this method can be scaled down to laboratories for non-invasive temperature mapping of 3D integrated circuits

A study of stress gradients in a titanium alloy

A study of the stress gradient developed in a Ti-7AL sample is examined using the technique of High-Energy Diffraction Microscopy. The experiment is conducted at beamline 1-ID of the Advanced Photon Source of Argonne National Laboratory, using high-resolution monochromator. A map of grain orientation in the cross-section of the sample is determined through use of a near-field technique. The near-field study is complemented by analysis using data from a far-field detector to develop lattice strain on a grain-by-grain basis. A state of bending with superposed tension is revealed through correlation of the near-field grain map with the far-field center of mass result. A comparison of “macro” stress and the “grain scale” stresses is featured. An assessment is given on the benefits and limitations of using the high-resolution monochromator in the strain analysis of far-field detector images

Characterization of Irradiation Damage Using X-Ray Diffraction Line-Profile Analysis

During operation, structural components made of zirconium alloys are subject toneutron irradiation, which leads to the displacement of zirconium atoms fromtheir lattice sites, the production of self-interstitials and vacancies, and eventually dislocation loops. This process can lead to deleterious effects such as irradiation growth, creep, and embrittlement as well as accelerated aqueous corrosion. Quantitative analysis of dislocation line densities is seen as an importantpathway for distinguishing between the irradiation response of different alloys.The analysis of irradiation damage using X-ray diffraction (XRD) line-profile analysis has proven to be a powerful complementary technique to transmissionelectron microscopy, which samples a comparatively large volume and is lessaffected by the subjectivity of image analysis. In this paper we present andanalyze three different types of XRD experiments, describing their purpose andthe new insight achieved using each technique. First, we present work carriedout on neutron-irradiated samples, comparing dislocation line densities measured by XRD with macroscopic growth measurements. A second experimentusing a synchrotron-based X-ray microbeam enabled the mapping of dislocationline densities as a function of depth from the surface of proton-irradiated zirconium alloys. These data are compared with calculated damage profiles, providingnew insight into the early saturation of damage. Finally, the last example presented here focuses on synchrotron-based 3D XRD measurements, for whichdislocation-loop line densities were analyzed in hundreds of individual grains,providing excellent statistics about the grain-to-grain variability of line densities