Vapor-liquid-solid growth of Ge nanowhiskers enhanced by high-temperature glancing angle deposition

We have demonstrated that the vapor-liquid-solid (VLS) growth of Ge nanowhiskers is significantly enhanced by high-temperature glancing angle deposition (HT-GLAD). At the substrate temperature of 420°C, the Ge nanowhiskers grow on the sample deposited at the deposition angle of α =85°, whereas no long nanowhisker grows on the samples deposited at α ≤73°. The kinetic growth model that takes into account the directional incidence of the vapor flux agrees with the experimental results and suggests that the atoms deposited on the side surface of the nanowhiskers play an essential role in the HT-GLAD assisted VLS growth. Supplying the atoms on the side surface of the nanowhiskers is expected to accelerate the growth of the nanowhiskers in any vapor phase growth methods, such as molecular beam epitaxy and chemical vapor deposition.