Pushing the boundaries of electron devices—from transistors to photovoltaics—demands complete control over device architectures and material systems. However, traditional growth and fabrication techniques often fall short when optimal design calls for non-planar geometries or integration of non-epitaxial material systems. Thus, development of techniques for X-on-Y growth and integration, such as: (i) bottom-up growth of geometry and shape-controlled nanowires, (ii) integration of dissimilar material systems such as III-V’s and Si, and (iii) direct growth of high-quality semiconductors on metals are critical. In this talk, I discuss how semiconductor layer transfer techniques can be used to fabricate high-mobility III-V transistors on Si substrates, and the vapor-liquid-solid (VLS) growth mode can be used to grow templated nanowires and high-quality InP thin films directly on metal foils. Specifically, I will cover three methods that move towards enabling X-on-Y. First, I will show a compound semiconductor on insulator (XOI) layer transfer technique that enables integration of free-standing, ultra-thin III-V membranes on Si substrates. The second method is a templated VLS nanowire growth technique for 3-D semiconductor structures on metal substrates. The last technique I illustrate is a thin-film vapor-liquid-solid growth technique for the direct growth of both polycrystalline and single crystalline InP on non-epitaxial substrates.
Rehan Kapadia received his BS in electrical engineering from the University of Texas at Austin in 2008, and his MS/PhD in electrical engineering from the University of California, Berkeley in 2010 and 2013, respectively. He is starting as an assistant professor at University of Southern California in July 2014. He was a National Science Foundation Graduate Student Fellow, and won the David J. Sakrison Prize from the Electrical Engineering and Computer Sciences department at UC Berkeley for best dissertation. His research interests center on material growth techniques that enable high-performance, scalable electronics.