Towards Understanding Early Failures Behavior during Device Burn-In: Broadband RF Monitoring of Atomistic Changes in Materials.

In this paper, we attempt to understand the physico-chemical changes that occur in devices during device "burn-in". We discuss the use of low frequency dielectric spectroscopy to detect, characterize and monitor changes in electrical defects present in the dielectrics of through silicon vias (TSV) for three dimensional (3D) interconnected integrated circuit devices, as the devices are subjected to fluctuating thermal loads. The observed changes in the electrical characteristics of the interconnects were traceable to changes in the chemistry of the isolation dielectric used in the TSV construction. The observed changes provide phenomenological insights into the practice of burn-in. The data also suggest that these "chemical defects" inherent in the 'as-manufactured' products may be responsible for some of the unexplained early reliability failures observed in TSV enabled 3D devices.

Quantitative Chemically Specific Coherent Diffractive Imaging of Reactions at Buried Interfaces with Few Nanometer Precision.

We demonstrate quantitative, chemically specific imaging of buried nanostructures, including oxidation and diffusion reactions at buried interfaces, using nondestructive tabletop extreme ultraviolet (EUV) coherent diffractive imaging (CDI). Copper nanostructures inlaid in SiO2 are coated with 100 nm of aluminum, which is opaque to visible light and thick enough that neither visible microscopy nor atomic force microscopy can image the buried interface. Short wavelength high harmonic beams can penetrate the aluminum layer, yielding high-contrast images of the buried structures. Quantitative analysis shows that the reflected EUV light is extremely sensitive to the formation of multiple oxide layers, as well as interdiffusion of materials occurring at the metal-metal and metal-insulator boundaries deep within the nanostructure with few nanometers precision.