In the work of Janson et al., an experimental study of deuterium (2H) diffusion in B- and Al-doped SiC was performed. A trap-limited diffusion model was used as a basis for analysis. Using the same model, the concept of a dynamical reaction front was introduced: a distinctive well-defined zone to which the reaction of the D-dopant complex formation was confined. This zone lay between the already-deuterated and the non-deuterated regions and gradually penetrated into the specimen. Analytical expressions were obtained for the spatial profiles of the free and complexed D and for the reaction-rate profiles. The analysis predicted that the reaction zone width initially remains constant as the zone progresses into the sample; yet, after a certain time, the zone starts to widen proportionally to the square root of time. An alternative method of experimental analysis was proposed, wherein the reaction zone position and width as functions of time were measured. This was expected to yield the same process parameters, as determined by the method of Janson and others.

Hydrogen Diffusion in Acceptor-Doped Silicon Carbide - Implementation of the Reaction Zone Concept. M.Sinder, Z.Burshtein, J.Pelleg: Physical Review B, 2008, 77[9], 094128 (8pp)