Structural characterization of double stacking faults induced by cantilever bending in nitrogen-doped 4H-SiC

Abstract

Defects in highly nitrogen-doped 4H-SiC deformed by cantilever bending at 550 C have been identified by weak-beam and high-resolution transmission electron microscopy techniques. The induced-defects consist of double stacking faults (DSFs) whose expansion produces a local 4H ! 3C phase transformation. Each DSF is bound by two identical 30 Si(g) partial dislocations which glide on two adjacent basal planes. The DSFs belong to three different populations which differ by their extension as a function of the applied-stress and the 30 Si(g) characteristics (line direction L, Burgers vector b, glide planes and glide direction). The external mechanical stresses are the main driving forces involved in the DSF expansion. However, extra driving forces such as thermodynamic or electronic forces are also likely to be involved.

Defects created in N-doped 4H-SiC in the brittle regime: Stacking fault multiplicity and dislocation cores

“…The etch patterns obtained on the ð11 20Þ face in all the samples annealed at 823 K [12] or at 973 K ( Figure 2) consist of lines that stretch at 45 from the scratch and thus are parallel to the basal planes. They correspond to the intersections of planar Philosophical Magazine 1253 defects with the surface.…”

“…The density of created defects being low enough, it was possible to characterise individual stacking faults and their bounding PDs by coupling chemical etching and TEM techniques (WB-DF and HRTEM imaging) with image contrast analysis and dislocation core reconstructions. In a first study performed at 823 K, we have characterised DSFs dragged by Si(g) PDs [12,13]. However, because of the above mentioned discrepancies, we found it interesting to perform further investigations paying attention to obtain good statistics on the fault stacking and core composition of the PDs.…”

“…HRTEM studies were carried out with a 2010-FEG Jeol TM microscope equipped with a GIF and a CCD camera (Gatan TM ) or a 4000EX Jeol TM microscope equipped with a CCD camera (Gatan TM ). A few focal series were performed [12] but most of the defects were imaged when the minimum of contrast was obtained on the amorphous layer created by the thinning process. Indeed, such a defocus could unambiguously be selected during the experiments.…”

Plasticity and deformation microstructure of 4H‐SiC below the brittle‐to‐ductile transition

“…Indeed, this temperature domain was investigated with other techniques (cantilever bending at 550 °C (Regula et al [10]), micro-indentations of prismatic planes at 400 °C and 675 °C (Mussi et al [11]) and microindentation of the basal plane (Hong et al [12])). Compression of 4H-SiC at 500 °C creates numerous silicon and carbon core leading partial dislocations in the basal plane, associated with highly extended SFs, and few perfect dislocations on a first order pyramidal plane.…”

8H-, 10H-, 14H-SiC formation in 6H-3C silicon carbide phase transitions

“…In terms of the dislocation, the transition mechanism of the cubic structure to the hexagonal structure is discussed in the articles [1][2][3][4][5][6][7]. In terms of formation of the multilayers polytypes, transition of the hexagonal structure to the cubic one is discussed in [8][9][10][11][12][13].…”