Heat- and electron-beam-induced transport of gold particles into silicon oxide and silicon studied by in situ high-resolution transmission electron microscopy
1 Electron Microscopy Group of Materials Science, University of Ulm, D-89081 Ulm and
2 Institute of Photonic Technologies, D-07743 Jena, Germany
* To whom correspondence should be addressed. E-mail: johannes.biskupek{at}uni-ulm.de
In this study, we describe the transport of gold (Au) nanoparticles from the surface into crystalline silicon (Si) covered by silicon oxide (SiO2) as revealed by in situ high-resolution transmission electron microscopy. Complete crystalline Au nanoparticles sink through the SiO2 layer into the Si substrate when high-dose electron irradiation is applied and temperature is raised above 150°C. Above temperatures of 250°C, the Au nanoparticles finally dissolve into fragments accompanied by crystallization of the amorphized Si substrate around these fragments. The transport process is explained by a wetting process followed by Stokes motion. Modelling this process yields boundaries for the interface energies involved.
Keywords HRTEM, in situ TEM, electron irradiation, Au nanoparticles
Received 18 December 2007, accepted 30 April 2008