Transient-enhanced Si diffusion on native-oxide-covered Si(001) nanostructures during vacuum annealing

We report on the transient-enhanced shape transformation of nanostructured Si(001) surfaces upon in vacuo annealing at relatively low temperatures of 900–950 °C for a few minutes. We find dramatic surface mass transport concomitant with the development of low-energy facets on surfaces that are covered by native oxide. The enhanced surface mass transport ceases after the oxide is completely desorbed, and it is also not observed on surfaces where the native oxide had been removed by HF before annealing.