Atomic-scale compositional structure of InAsP/InP and InNAsP/InP heterostructures grown by molecular-beam epitaxy

Abstract

Thermally detected optical absorption, reflectance, and photoreflectance of In(As,P)/InP quantum wells grown by gas source molecular beam epitaxy Differential gain and threshold current of 1.3 μm tensile-strained InGaAsP multi quantum well buriedheterostructure lasers grown by metalorganic molecular beam epitaxial growth Cross-sectional scanning tunneling microscopy ͑STM͒ has been used to characterize the atomic-scale structure of InAs 0.35 P 0.65 /InP and InN 0.01 As 0.35 P 0.64 /InP strained-layer multiple quantum well structures grown by gas-source molecular-beam epitaxy. Atomically resolved STM images of the ͑110͒ cross-sectional plane reveal nanoscale clustering within the InAs x P 1Ϫx alloy layers, with the boundaries between As-rich and P-rich regions in the alloy layers appearing to be preferentially oriented along the ͓112͔ and ͓112͔ directions in the ͑110͒ plane. ͑110͒ cross-sectional images reveal that considerably less compositional variation appears within the ͑110͒ plane; features elongated along the ͓110͔ direction are observed, but few ͗112͘ boundaries are seen. These observations suggest that the boundaries between As-rich and P-rich clusters may form preferentially within the ͑111͒ and ͑111͒ planes. Comparisons of filled-state images of InAs x P 1Ϫx /InP and InN x As y P 1ϪxϪy /InP heterostructures suggest that N incorporation increases the valence-band offset in InN x As y P 1ϪxϪy /InP compared to that in InAs x P 1Ϫx /InP.

Determination of the flow and activation energy of phosphorus desorption during annealing of an InP(001) substrate in an arsenic flux under molecular beam epitaxy conditions

“…Phosphorus is tried not to be used in the annealing process of substrates, since it is difficult to remove it from the growth chamber, and the presence of phosphorus in the growth chamber during HES growth results in its uncontrolled incorporation into epitaxial layers [12]. The incorporation of phosphorus into epitaxial layers results to the formation of quaternary interface layers with rough heterointerfaces [13]. Annealing in an arsenic flux is preferable, since arsenic is more easily removed from the growth chamber, and arsenic-based HESs have smoother heterointerfaces and make it possible to create devices with a wider operating temperature range [14].…”

Combined atomic force microscopy and scanning tunneling microscopy imaging of cross‐sectioned GaN light‐emitting diodes

“…Scanning tunneling microscopy (STM) is one of few techniques capable of characterizing the structural and electronic properties of semiconductors on a nanometer to atomic scale. Because of the sensitivity of the tunneling current to local variations in the nature of the surface, it has been used extensively to locate p-n junctions in silicon (Fukutome et al 1999, Hosaka et al 1988, Kordic et al 1990, 1991Yu et al 1992) and GaAs (Dagata and Tseng 1993, Feenstra et al 1992, Gwo et al 1993, Silver et al 1995, and heterojunctions in a multitude of III-V compound semiconductors such as InGaAsP/InAsP (Grandidier et al 1999) and GaN/GaAs (Goldman et al 1996) superlattices, (InGa)As/GaAs (Gwo et al 1993, Zheng et al 1994) multiple quantum wells (MQWs), and InAsP/InP (Zuo et al 1998), GaAs/AlGaAs (Dagata et al 1992), and InAs/GaSb/AlSb (Harper et al 1998) heterostructures. Under ultra high vacuum conditions, STM has also been used to measure dopant levels in silicon via atom counting (Chao et al 1998, Nuffler et al 2000 and element segregation (Zheng et al 1994) in cross-sectioned III-V semiconductors with atomic resolution.…”