Achievement

The production of atomically flat silicon surfaces is a long-standing technological challenge, as atomic-scale roughness degrades the performance of transistors. IGERT Fellow Brandon Aldinger used a combination of scanning tunneling microscopy and vibrational spectroscopy to produce silicon surfaces of surprising and unprecedented smoothness with a simple aqueous etchant that selectively removes every other row of silicon, producing a H-terminated surface. This unusual missing row morphology minimizes interadsorbate stress. The chemical origins of this perfection were uncovered, in part, by a new spectroscopic technique that simplifies the analysis of the H/Si(100) spectrum. With this technique, Aldinger showed that the commonly accepted spectral assignments were very wrong. He is currently modeling the vibrational spectrum using ab initio techniques. A definitive assignment of the spectrum will allow scientists to quickly and accurately assess the morphology of silicon surfaces.