Characterization and Formation Mechanism of Six Pointed Star-Type Stacking Faults in 4H-SiC

Optical investigations techniques used for stacking faults characterization in SiC

Stacking Faults (SFs) are important crystal defects in 4H-SiC [1]. They can be electrically active and, in this case, behave as deep quantum well (QW) traps for electrons [2]. This leads to the degradation of high voltage bipolar diodes [3]. The basic origin of SFs in SiC is the small total energy difference between two different polytypes. The net consequence is that they can appear spontaneou...

Optical Investigations of stacking faults in 4H-SiC epitaxial layers: comparison of 3C and 8H polytypes

We present an analysis of the electronic structure of in-grown 3C and 8H stacking faults (SFs) in a 4H-SiC matrix. First the concept of low temperature photoluminescence optical signature of SFs is discussed. Then, the results of type-II quantum well (QW) model calculations are displayed, taking into account the effect of valence band offset, internal polarization field and non homogeneity of t...

Shockley-Frank stacking faults in 6H-SiC

Electronic driving force for stacking fault expansion in 4H-SiC

Trapping of electrons in stacking fault SF interface states may lower the energy of a SF more than it costs to form the SF. This “electronic stress” driving force for SF expansion is evaluated for single and double stacking faults in 4H-SiC in terms of a two-dimensional free-electron density of states model based on first-principles calculations. In contrast with previous work, which claimed th...

Effect of Inter-Well Coupling between 3C and 6H in-Grown Stacking Faults in 4H-SiC Epitaxial Layers

Both 3C and 6H stacking faults have been observed in a low doped 4H-SiC epitaxial layer grown in a hot-wall CVD reactor on a heavily doped (off-axis) 4H-SiC substrate. They appear differently on the different parts of sample, with energetic dispersion ranging from 3.01 eV to 2.52 eV. Since they behave as natural type-II quantum wells in the 4H-SiC matrix, the thickness dependence of the exciton...