Defects created in N-doped 4H-SiC by flexion in the brittle regime: Stacking fault multiplicity and dislocation cores.
Résumé
Defects are introduced in N-doped 4H-SiC by surface scratching and bending at 823K or 973K. They are characterized by weak beam-dark field TEM, HRTEM, LACBED, image analysis and dislocation core reconstructions. They consist of double stacking faults (DSFs) dragged by PD pairs in planes in which the Si-C dumbbells have the same orientation. The PDs forming a pair always have the same Burgers vectors. The reconstructions prove that their core composition depends on the dislocation character, the expansion direction and the orientation of the dumbbells in the glide planes. Only Si(g) are mobile, the lack of mobility of C(g) explaining why only three kinds of half-loops expand and why one DSF is always edged by two identical PDs. It is shown that the line morphology is not a sufficient criterion to determine the core composition. Though mechanical stresses are applied, extra thermodynamic and/or electronic driving forces influence the DSF formation in our experiments.
Origine | Fichiers produits par l'(les) auteur(s) |
---|
Loading...