Theoretical investigations of a highly mismatched interface: SiC/Si(001)

Abstract

Using first principles, classical potentials, and elasticity theory, we investigated the structure of a semiconductor/semiconductor interface with a high lattice mismatch, SiC/Si͑001͒. Among several tested possible configurations, a heterostructure with ͑i͒ a misfit dislocation network pinned at the interface and ͑ii͒ reconstructed dislocation cores with a carbon substoichiometry is found to be the most stable one. The importance of the slab approximation in first-principles calculations is discussed and estimated by combining classical potential techniques and elasticity theory. For the most stable configuration, an estimate of the interface energy is given. Finally, the electronic structure is investigated and discussed in relation with the dislocation array structure. Interface states, localized in the heterostructure gap and located on dislocation cores, are identified.

Nature of interfacial defects and their roles in strain relaxation at highly lattice mismatched 3C-SiC/Si (001) interface

“…As mentioned earlier, Pizzagalli et al 13 has theoretically investigated the 3C-SiC/Si ͑001͒ interface and showed that the Lomer misfit dislocation network pinned at the strained interface was the most efficient mechanism for the strain relaxation with particular the CSS type of Lomer dislocations. In our case, based on our detailed structural characterization of interfacial defects, an atomic model of the 3C-SiC/Si interface structure can be given in Fig.…”

“…10,11 Therefore, this model cannot be applied to the practical interface structure of thick 3C-SiC films on carbonized Si substrates. An ab initio study 12,13 of the 3C-SiC/Si ͑001͒ interface formation showed that ͑i͒ the edge misfit dislocation network pinned at the interface was the most efficient mechanism for the strain relaxation and ͑ii͒ the reconstructed dislocation core with a carbon substoichiometry might be the most stable configuration according to the computed configuration energy. However, this core structure model is different from the stoichiometric model determined by the scanning transmission electron microscopy ͑STEM͒ investigation of the 3C-SiC/Si ͑001͒ interface.…”

“…A theoretical investigation of dislocations in the 3C-SiC/Si ͑001͒ interface by Pizzagalli et al 13 suggested two stable Lomer dislocation configurations, named S1a and CSS, with their structural models illustrated in Fig. 5.…”

Strain Tailoring in 3C‐SiC Heteroepitaxial Layers Grown on Si(100)

“…8 × 10 -3 , but this is enough to introduce excess dislocations and strain. [20] Increasing the Si parameter by adding an amount of Ge will reduce this mismatch and hence help to improve the 3C-SiC layer quality. Of course, it would be fortuitous that both the TEC and the ratio match for the same x.…”

Restoring defect structures in 3C-SiC/Si (001) from spherical aberration-corrected high-resolution transmission electron microscope images by means of deconvolution processing

“…The former is composed of a five and a seven atomic membered rings, while the latter is composed of a six and an eight atomic membered rings. Two possible structure models of Lomer dislocation cores, CSS and S1a, were proposed for the case of 3C-SiC/Si (0 0 1) interface, based on the theoretical calculation (Pizzagalli et al, 2003) and 200 kV LaB 6 electron microscope observation combining deconvolution processing (Wen et al, 2009). The models projected in the [1 1 0] direction are shown in Figs.…”