Anisotropy and growth-sequence dependence of atomic-scale interface structure in InAs/Ga1−xInxSb superlattices

Abstract

We have used cross-sectional scanning tunneling microscopy to study the atomic-scale interface structure of InAs/Ga1−xInxSb superlattices grown by molecular beam epitaxy. Detailed, quantitative analysis of interface profiles obtained from constant-current images of both (110) and (11̄0) cross-sectional planes of the superlattice indicate that interfaces in the (11̄0) plane exhibit a higher degree of interface roughness than those in the (110) plane, and that the Ga1−xInxSb-on-InAs interfaces are rougher than the InAs-on-Ga1−xInxSb interfaces. The roughness data are consistent with anisotropy in interface structure arising from anisotropic island formation during growth, and in addition a growth-sequence-dependent interface asymmetry resulting from differences in interfacial bond structure between the superlattice layers.

Interpreting interfacial structure in cross-sectional STM images of III–V semiconductor heterostructures

“…Depending on which layer ends up on the (11 : 0) surface, however, the anisotropy can be observed in XSTM measurement of roughness on the two different cleavage surinterface as viewed by XSTM will have one of two possible profiles. Following the notation defined faces [9]. above, the XSTM profile will either show the 'odd' growth layers, −1, +1, +3,… ( Fig.…”

“…Although state-of-the-art epitaxial scattering mechanisms of carriers across interfaces growth techniques such as molecular beam epitaxy [1,2], as well as by causing local deviations in the (MBE ) can deposit material with sub-monolayer band offsets [3]. precision, it is challenging nonetheless to create During the last decade, cross-sectional scanning perfectly abrupt interfaces given all the kinetic and tunneling microscopy ( XSTM ) has emerged as a thermodynamic factors that influence interface forpowerful technique to characterize III-V semiconductor heterostructure interfaces [4][5][6][7][8][9][10]. This tech- .…”

Thermodynamic analysis of anion exchange during heteroepitaxy

“…In a GaInSb/InAs superlattice, InSb-like bonds can be formed at the GaInSb-on-InAs interface by appropriately controlling the anion exchange. This is desirable, because InSb-like bonds at the interface offer superior structural and electronic properties [7][8][9]. More recently, Kaspi et al reported excellent structural and optical properties in an InAs/GaSb superlattice structure [40], which was grown in such a manner that InSb-like bonds were formed at the GaSb-on-InAs interfaces, while GaSb-like bonds were formed at the InAs-onGaSb interfaces by As/Sb exchange [41,42].…”

“…(1), (8) and (9) to get P A2 =P B2 and plugging it into Eq. (7), Table 1 Equilibrium constants for sublimation of III-V Compounds and the maximum sublimation temperature (T sub1 ) and the temperature of non-congruent dissociation (T sub2 ) we get…”

Subband structure of two-dimensional electron gases in SrTiO3

“…Similar to 2DEGs in III-V heterostructures 40,41 there exists an inherent asymmetry between the 2DEGs formed at SrTiO 3 /GdTiO 3 and GdTiO 3 /SrTiO 3 interfaces, respectively. Specifically, when SrTiO 3 is grown on GdTiO 3 , the 2DEG shows lower mobility and slightly lower carrier concentration ($2 Â 10 14 cm À2 ).…”