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 (N-2) or oxidizing (O-2) ambients at 850degreesC 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 N-2 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.
Diffusion and clustering of supersaturated carbon in SiGeC layers under oxidation
Napolitani E;
2002
Abstract
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 (N-2) or oxidizing (O-2) ambients at 850degreesC 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 N-2 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.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.