Appl. Phys. Lett. 99, 143115 (2011.10) [pdf]

Stress Evolution During the Oxidation of Silicon Nanowires in the Sub-10nm Diameter Regime

Byung-Hyun Kim, Mauludi Ariesto Pamungkas, Mina Park, Gyubong Kim, Kwang-Ryeol Lee, Yong-Chae Chung
 

Using a reactive molecular dynamics simulation, the oxidation of Si nanowires (Si-NWs) with diameters of 5, 10 and 20 nm was investigated. The compressive stress at the interface between the oxide and the Si core decreased with increasing curvature in the sub-10 nm regime of the diameter, in contrast to the theory of self-limiting oxidation where rigid mechanical constraint of the Si core was assumed. The Si core of the thinner Si-NW was deformed more with surface oxidation, resulting in a lower compressive stress at the interface. These results explain the experimental observation of full oxidation of very thin Si-NWs.