From Science to Technology

Nanotechnology has a longer history than what is usually supposed it to have. The bio-inspired concept of encoding big data in a tiny space (as related to cracking of the DNA code in 1953) was firstly envisioned in a top-down perspective by Richard Feyneman, the Nobel Prize physicist, in the famous CalTech conference of December 1959 “There’s plenty of room at the bottom”. Just sixty years ago. Actually, the very first nanostructured material was obtained a dozen years later by Leo Esaki, the Nobel Prize winner in 1973, who invented the semiconductor multiple quantum-well… and the word “Nano-Technology”. This nanostructure readily entered the industrial production for semiconductor lasers and accompanied the development of the CD players, not limited to this application. The microelectronic industry supported the race towards top-down nanotechnology, accomplishing the requirements of Moore’s law in ICs, independently and previously of the nano-science boom. Nowadays, many self-assembled semiconductor nanostructures are currently studied and implemented for microelectronic, optoelectronic and photovoltaic applications: quantum dots, nanowires, very recently fins and vertical nanomembranes. Still, the challenge for industrial applications are always the same: uniformity in size and shape, ordering in arrays and crystal quality with respect to defects and compositional intermixing. I will discuss these issues, with some examples, and set the point of the complex interplay of thermodynamic and kinetic driving forces in the epitaxial deposition of three-dimensional, facetted nanostructures.