A study of surface cross-hatch and misfit dislocation structure in grown by chemical beam epitaxy

Modulation spectroscopy study of a strained layer GaAs/GaAsP multiple quantum well structure

“…The data exhibits no "cross-hatch" patterns associated with the misfit dislocations which accompany strain relaxation. 30 This indicates that the layer thickness d b = 230 Å is below the critical value and that the barrier layers in this particular MQW structure are under the full tensile strain. Figure 6 displays the surface topography for a GaAs 0.74 P 0.26 epilayer 2000 Å thick grown on a GaAs layer 2000 Å thick.…”

“…Atomic force microscopy (AFM) measurements applied to GaAs 0.97 P 0.03 /GaAs 0.71 P 0.29 MQW structure with a top GaAs 0.71 P 0.29 barrier layer of thickness 230 Å exhibited no "cross-hatch" patterns associated with misfit dislocations. 30 This indicates that the GaAsP barrier layers are pseudomorphic, i.e., under full tensile lattice mismatch strain.…”

Ordering growth of InAs quantum dots on ultra-thin InGaAs strained layer

“…These dislocations have special directions, so people want to use them to fabricate ordered QDs [4,5]. For example, Fumito Hiwatashi [4] found InAs QDs mainly aligned along [1][2][3][4][5][6][7][8][9][10] on InGaAs layer and thought that was because QDs prefer nucleating in the strainrelaxed regions of the strained layers. But, the regions with dense QDs they got were relatively wide, so the result they got cannot be called perfect ordering growth.…”

In situ detection of an initial elastic relaxation stage during growth of In0.2Ga0.8As on GaAs(0 0 1)

“…As the growth proceeds, an increasing amount of accumulated elastic energy makes the layer to become metastable and the relaxation process begins [1,2]. Relaxation of low-strained layers ( < 2 %) usually takes place through misfit dislocations, and it is well known that the surface of these layers develops an undesired crosshatched morphology once the mechanisms for plastic relaxation start [3][4][5]. Furthermore, some studies on the low-mismatched SiGe/Si [6,7] and In x Ga 1-x As/InP (x  0.53) [8] systems have shown that the surface can also roughen prior to the generation of misfit dislocations and the subsequent crosshatch development.…”