CARBON DIFFUSION THROUGH SiO2 FROM A HYDROGENATED AMORPHOUS CARBON LAYER AND ACCUMULATION AT THE SiO2/Si INTERFACE

• Published in: Jpn.J.Appl.Phys ,Part 1. Vol. 40, no. 4A, pp. 2197-2200. 2001 Vol. 40; no. 4A; pp. 2197 - 2200
• Main Authors: Krafcsik, O H, Vida, G, Pocsik, I, Josepovits, K V, Deak, P
• Format: Journal Article
• Language: English
• Published: 2001
• ISSN: 0021-4922
• DOI: 10.1143/JJAP.40.2197

C diffusion in a SiO2/Si system was investigated. The source was provided by CVD of a hydrogenated amorphous C layer onto the oxide at low temperature. From layers with low O content, no C outdiffusion was detected up to 1190 C. If the O content was high, the diffusion would start suddenly at 1140 C, and C accumulation would be found on the Si side of the SiO2/Si interface in the form of SiC precipitates. These results are interpreted by assuming O-assisted dissociation of C atoms from the C layer in form of CO molecules, fast CO diffusion through SiO2 and an exothermic reaction of CO with Si. No C segregation was found in SiO2. Consequences of C island formation during SiC oxidation are pointed out. 13 refs.