A new model for in situ nitrogen incorporation into 4H-SiC during epitaxy

Un nouveau modèle d'incorporation de l'azote pendant la croissance épitaxiale du 4H-SiC

Gabriel Ferro (1) , Didier Chaussende (2)

1 LMI - Laboratoire des Multimatériaux et Interfaces
2 LMGP - Laboratoire des matériaux et du génie physique

Nitrogen doping of 4H-SiC during vapor phase epitaxy is still lacking of a general model explaining the apparently contradictory trends obtained by different teams. In this paper, the evolutions of nitrogen incorporation (on both polar Si and C faces) as a function of the main growth parameters (C/Si ratio, temperature, pressure and growth rate) are reviewed and explained using a model based on surface exchanges between the gas phase and the uppermost 4H-SiC atomic layers. In this model, N incorporation is driven mainly by the transient formation of C vacancies, due to H 2 etching, at the surface or near the surface. It is shown that all the growth parameters are influencing the probability of C vacancies formation in a similar manner as they do for N incorporation. The surface exchange model proposes a new framework for explaining the experimental results even beyond the commonly accepted reactor type dependency.

Domaines: Matériaux; Matériaux

Gabriel Ferro, Didier Chaussende. A new model for in situ nitrogen incorporation into 4H-SiC during epitaxy. Scientific Reports, 2017, 7, pp.43069. ⟨10.1038/srep43069⟩. ⟨hal-01615178⟩