Ultrafast Electro-thermal Transport Through Nanoscale Electronic Materials and Interfaces

Download or read book Ultrafast Electro-thermal Transport Through Nanoscale Electronic Materials and Interfaces written by Christopher Perez and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Although silicon-based nanofabrication technology has satisfied computational demands for decades, the aggressive scaling of complementary metal oxide semiconductor (CMOS) technology to sub-5 nm geometries poses challenges that must be addressed at the materials level. One example is tuning electro-thermal transport in metal nanostructures to enhance the transfer of information and the dissipation of heat in integrated circuits. The manipulation of these pathways can be further optimized by integrating low-temperature passivation materials with varying thermal conductivities. Furthermore, the emergence of photonic interconnects presents an opportunity for the integration of electro-optic components that rely heavily on the movement, transfer, and recombination of charge carriers within photosensitive materials. All the above are governed by the fundamental limits of physical transfer mechanisms in semiconductors, bringing electron and phonon engineering --the control of heat and charge carriers in materials-- to the forefront of CMOS hardware design. This work explores the fundamental mechanisms and limits of electron-phonon transport in four individual material systems which can comprise different parts of a broader, electro-thermally optimized electronic system using primarily time-domain thermoreflectance (TDTR) and scanning ultrafast electron microscopy (SUEM) as probes. First, we discuss the electro-thermal characterization of iridium (Ir) as an emerging metal for high aspect ratio nanostructures on account of its favorable resistivity scaling with thickness. The exceptionally defect-free metal films offer minimal confounding microstructural effects and allow the probing of thermal anisotropy and cross-plane quasi-ballistic thermal transport in epitaxial Ir(001) interposed between Al and MgO(001). Such effects reveal a transition between three dominant cross-plane thermal transport mechanisms which include electron dominant, phonon dominant, and electron-phonon energy conversion dominant regimes at different thicknesses. Finally, we develop a phenomenological model that correctly describes the dominant transport regimes, providing insight into the thickness-dependent interplay between carriers in metals as well as enabling quick evaluation and potential scalability to broader material systems. Next, we describe defect-modulated thermal transport in sputtered aluminum nitride (AlN) thin films for enabling wide-bandgap (WBG), high-temperature, and high-power electronic devices deposited at back-end of the line (BEOL) compatible temperatures (