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Misfit dislocation formation in lattice-mismatched III - V heterostructures grown by metal - organic vapour phase epitaxy
| Content Provider | Semantic Scholar |
|---|---|
| Author | Nijenhuis, Jan Te Wel, P. J. Van Der Eck, E. Van Giling, L. J. |
| Copyright Year | 1996 |
| Abstract | Misfit dislocation formation in lattice-mismatched III - V heterostructures both under tensile and under compressive stress has been studied. Layers of GaAs under tensile stress have been grown by metal - organic vapour phase epitaxy on substrates with indium concentrations between 0.1 and 1.1%. Compressively strained layers with indium concentrations between 0.5 and 2.5% have been grown on GaAs substrates. For the layers under tensile stress an asymmetrical dislocation pattern has been observed, whereas the compressively strained layers show a symmetrical dislocation pattern. A model describing the relaxation process by the formation of dissociated hexagonally shaped half-loop dislocations is proposed. A difference in the mobilities of the two possible misfit dislocation types is found to be the origin of asymmetrical strain relief at low growth temperatures. In layers under tensile stress the cross slipping of screw dislocations is counteracted by the shear stress, leading to relaxation in only one direction. In layers under compressive stress the nucleated misfit dislocations can undergo cross slipping, resulting in a cross hatched pattern at the surface. At higher growth temperatures the dislocation patterns become more symmetrical due to the higher dislocation mobilities. Growth hillocks are formed on the surfaces of the layers grown under tensile stress, due to local accumulation of dislocations. This hillock growth is prevented at higher growth temperatures by the higher mobility of the dislocations. It is also shown that the (mis)orientation of the substrate is revealed by non-parallel groups of dislocation lines observed at the surface of a relaxed epilayer. |
| Starting Page | 2961 |
| Ending Page | 2970 |
| Page Count | 10 |
| File Format | PDF HTM / HTML |
| DOI | 10.1088/0022-3727/29/12/004 |
| Volume Number | 29 |
| Alternate Webpage(s) | https://repository.ubn.ru.nl/bitstream/handle/2066/28313/28313___.PDF?sequence=1 |
| Alternate Webpage(s) | https://repository.ubn.ru.nl//bitstream/handle/2066/28313/28313___.PDF |
| Alternate Webpage(s) | https://doi.org/10.1088/0022-3727%2F29%2F12%2F004 |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
