Transmission electron microscopy study of the InP/InGaAs and InGaAs/InP heterointerfaces grown by metalorganic vapor-phase epitaxy

Abstract

InP/InGaAs and InGaAs/InP interfaces in heterostructures grown by metalorganic vapor-phase epitaxy (MOVPE) have been studied by transmission electron microscopy (TEM). Cross-sectional TEM 002 dark field images of the direct (InP–InGaAs) and inverted (InGaAs–InP) interfaces revealed a great difference in abruptness. Whereas the direct interface is always well defined and flat, the inverted one is compositionally graded and shows surface undulations. InP–InGaAs heterostructures were studied for different layer thicknesses and phosphine flow rates. The results indicate that this effect originates more from the substitution of arsenic by phosphorus atoms in subsurface InGaAs monolayers rather than from As carryover to the InP layer. The strong As–P exchange observed over several InGaAs monolayers is related to the large difference in chemical bond strength between Ga–As and Ga–P. This is supported by comparison with InP/InAlAs/InP and InP/In1−xGaxAsyP1−y/InP (0.1<x<0.4) heterostructures. The inverted InAlAs/InP interface is much more abrupt than the InGaAs/InP one and does not show any surface undulations. Furthermore, the In1−xGaxAsyP1−y/InP interface surface undulations increase with x composition. These results, valid for our experimental configuration, indicate that MOVPE grown InGaAs/InP interfaces can be improved by using very low hydride flow during the switching sequence.

Dark current investigation in thin P-i-N InGaAs photodiodes for nano-resonators

“…24 Because flaws introduced by these two mechanisms would strength the Shockley-Read-Hall (SRH) currents, we introduced an InAlAs layer at each SCR edge. InGaAs/InAlAs interfaces are very well defined, 23 and Zn has an abrupt profile in InAlAs. 25 The epitaxial stack of a typical junction dedicated to the GMR is illustrated in Table I.…”

“…First, the interfaces are not well defined because of the substitution of arsenic by phosphorus atoms in subsurface InGaAs monolayers. 23 That said, InP/InGaAs interfaces are much more abrupt than inverted ones. 23 Second, in InP, the element (zinc, Zn) used for p-type doping during growth is known to diffuse with a diffusion length of up to several hundred nanometers.…”

“…23 That said, InP/InGaAs interfaces are much more abrupt than inverted ones. 23 Second, in InP, the element (zinc, Zn) used for p-type doping during growth is known to diffuse with a diffusion length of up to several hundred nanometers. 24 Because flaws introduced by these two mechanisms would strength the Shockley-Read-Hall (SRH) currents, we introduced an InAlAs layer at each SCR edge.…”

Structural characterization of original 3D gallium structures grown by LP‐MOCVD

“…The 3D gallium structures growths were carried out in a low pressure metal-organic chemical vapor deposition system (LP-MOCVD) [15], with a deposition temperature varying between 500 and 700 °C, and a reactor pressure between 150 and 700 torr. Trimethyl-gallium (TMGa) was used as the gallium source, maintained in a cylinder at -10 °C.…”

InP–InxGa1−xAs core-multi-shell nanowire quantum wells with tunable emission in the 1.3–1.55 μm wavelength range

“…InGaAs-InP QWs grown on planar surfaces. [31][32][33][34] Some of the same causes are applicable to QWs grown around nanowires as the growth mechanism is similar (vapour-solid) in both cases despite the differences in facets, crystal phase and structure. Group V interdiffusion 32,[35][36][37] that takes place as a result of As-P exchange (which is promoted by the stronger chemical bond between Ga and P) 32 and the As carryover effect, [35][36][37] and surface undulations and roughening that growth and the subsequent growth interruption (before the second barrier growth)…”