Reduction of Lateral Dimension on InGaAs/GaAs Multilayers on Non-(111)V-Grooved GaAs(100) Substrate by Chemical Beam Epi
- PDF / 1,689,212 Bytes
- 6 Pages / 414.72 x 648 pts Page_size
- 89 Downloads / 194 Views
ABSTRACT We have found that the lateral dimension of InGaAs and GaAs multiple layers can be effectively controlled on non-( 11) V-grooved GaAs substrates by chemical beam epitaxy using triethylgallium and trimethylindium coupled with precracked arsine or unprecracked monoethylarsine. We suggest that this effect is due to the efficient migration of adatoms from (111) to non-(1 11) planes. This is an improved method which overcomes the difficulty that has been associated with the method of using only (11) V-grooves in which the lateral dimension is controlled by the differences in the growth rates between (111) and (100) planes. In case of InGaAs and GaAs epilayers, the anisotropy factors of growth rate were less than 0.1 at optimum growth temperature. Photoluminescence peak originated from InGaAs/GaAs quantum wire was significantly distinct from other peaks, suggesting an effective reduction of InGaAs lateral dimension.
INTRODUCTION Effects of small size and reduced dimensionality is expected to improve many physical properties of semiconductors and semiconductor base devices such as increased gain and higher modulation bandwidths of semiconductor lasers[l], high performance devices[2] and new transport phenomena[3]. The lateral patterning results in confinement of carriers in directions lying in the substrate plane. Lateral patterning of semiconductor heterostructure has been achieved by various techniques. Post-growth processing including electron or ion beam lithography followed etching[4,5], impurity-induced disordering using ion beam implantation[6], selective diffusion[7], and selective growth on patterned substrates[8,9]. However, the first three techniques produce serious interface damages during the introduction of exposed surfaces or impurities which can adversely affect the properties of the quantum efficiency. Therefore, the last technique using in situ process is more attractive since it is free from damages. But more studies are needed to evaluate its usefulness for quantum structure formation. Many studies have been tried to avoid the problem of excessive non-radiative interface recombination using V-grooved substrates since Bhat et aL reported the successful growth of the crescent-shaped quantum wire (QWR) arrays of AlGaAs/GaAs/AlGaAs on a V-grooves patterned GaAs substrate by metalorganic chemical vapor deposition (MOCVD)[10]. The major advantages of this technique using V-grooves are that the lateral interfaces are clean and defect-free, with the QWR being created in situ in a single growth step, and the fine-line lithography and etching are not essential. Recently, fabrication of QWR structures by utilizing the difference in the growth rates on different crystal orientation have been demonstrated[11,12]. Studies on the in situ growth 49 Mat. Res. Soc. Symp. Proc. Vol. 405 01996 Materials Research Society
of QWR are necessary to improve the efficiency of QWR devices. In this study, we have grown InGaAs/GaAs heterostructures on a non-( 11I) V-grooved GaAs(100) substrate by chemical beam epitaxy (
Data Loading...
