Influence of substrate misorientation on the structural quality of lattice matched GaAs/ScYbAs/GaAs structures

Abstract

Résumé. 2014 Nous avons réalisé la croissance de 2 hétérostructures GaAs (200 nm)/Sc0,2Yb0,8As (2 nm)/GaAs par épitaxie par jets moléculaires; la première sur une surface nominale (001), et la seconde sur une surface vicinale ((001), 4°vers (111)Ga, charnière [-110] [-110]). The structures have been characterized by reflection high energy electron diffraction, Rutherford backscattering analysis and transmission electron microscopy. The Sc0.2Yb0.8As layer is matched to GaAs and grows in a two-dimensional mode, leading to a high crystalline quality. But the GaAs overlayer contains a high density of planar defects, due to its three-dimensional growth. For the two structures, the nature of the faults, their density, and their distribution are compared. The quality of the GaAs overlayer is improved through growth on a vicinal surface. This conclusion is discussed with respect to the particular growth conditions and resulting morphology of the epilayers.

Lattice matched GaAs/Sc0.3Er0.7As/GaAs heterostructures grown on various substrate orientations

“…,. ,,,,,* ,111,#1,,1 ,' 8' ,' ,' ,' 8' ,' ,' ,1 t 8 I , 1 t 8 I #I,' (',';#(#yap,; #I,' (',';#(#yap,; '111",,1, '111",,1, 't""""c 't""""c ', \ \ \ ', \ \ \ \ \ \\ \ \ \\ \ \ \ \ ', (Sc,Er)As ', (Sc,Er)As , I #I I I FE.…”