In this growth, the strain is relieved instantaneously at the mismatched heterointerface unlike the traditional tetragonal distortion approach that relieves the strain after reaching a critical thickness.

Recently, a fundamentally different growth mode, interfacial misfit dislocation (IMF) growth mode, has been developed by our group. While this approach has enabled a number of device demonstrations, it exhibits several deficiencies such as the necessity to grow thick buffer layers (often >1 Ојm), poor thermal and electrical conductivity, and has resulted in significant material degradation through the presence of threading dislocations (TDs). In metamorphic buffer layer approach, initially the strain within the critical thickness is accommodated by tetragonal distortion followed by defect formation and filtering. Currently, this mismatch is accommodated via metamorphic buffer layers and strain-relief superlattices. However, the high (7.8%) lattice mismatch between the GaSb epilayer and the GaAs substrate complicates the growth of sophisticated device structures. This is because of the following reasons: GaAs is inexpensive, has favorable thermal properties, transparent to more (long wave length) active regions, forms excellent n and p ohmic contacts, and can be semi-insulating compared to GaSb. While recent technical advancements have enabled high quality lattice matched GaSb epitaxy on native substrates, for many applications GaAs substrates are desirable. Our results indicate that the IMF-grown GaSb is completely (98.5%) relaxed with very low density of threading dislocations (10 5 cm в€’2), while GaSb deposited using non-IMF growth is compressively strained and has a higher average density of threading dislocations (>10 9 cm в€’2).ДЄntimonide semiconductors have potential application in a wide range of electronic and opto-electronic devices due to their unique band-structure alignments, and small effective mass as well as high mobility for electrons. The proof for the existence of the IMF array and low threading dislocation density is provided with the help of transmission electron micrographs for the GaSb epitaxial layer. MoirГ© fringe patterns along with X-ray diffraction measure the long-range uniformity and strain relaxation of the IMF samples. In the present analysis, structural properties of GaSb deposited using both IMF and non-IMF growths are compared. The complete and instantaneous strain relief at the GaSb/GaAs interface is achieved by the formation of a two-dimensional Lomer dislocation network comprising of pure-edge (90В°) dislocations along both and.

Unlike the traditional tetragonal distortion approach, strain due to the lattice mismatch is spontaneously relieved at the heterointerface in this growth.

We report structural analysis of completely relaxed GaSb epitaxial layers deposited monolithically on GaAs substrates using interfacial misfit (IMF) array growth mode.

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