In this work we investigated the diffusion and clustering of supersaturated substitutional carbon in 200 nm thick SiGeC layers buried under a silicon cap layer of 40 nm. The samples were annealed in either inert (N2) or oxidizing (O2) ambients at 850 °C for times ranging from 2 to 10 h. The silicon self-interstitial (I) flux coming from the surface under oxidation enhances the C diffusion with respect to the N2 annealed samples. In the early stages of the oxidation process, the loss of C from the SiGeC layer by diffusion across the layer/cap interface dominates. This phenomenon saturates after an initial period (2-4 h) which depends on the C concentration. This saturation is due to the formation and growth of C containing precipitates which are promoted by the I injection and act as a sink for mobile C atoms. The competition between clustering and diffusion is discussed for two different C concentrations.
|Original language||English (US)|
|Number of pages||6|
|Journal||Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms|
|State||Published - Jan 1 2002|
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics