Scanning transmission electron microscopy of heterointerfaces grown by metalorganic vapor phase epitaxy (MOVPE)

doi:10.1016/0022-0248(91)90502-V

Journal of Crystal Growth

Volume 107, Issues 1–4, 1 January 1991, Pages 452-457

https://doi.org/10.1016/0022-0248(91)90502-V Get rights and content

Abstract

In this paper we report on the influence of a superlattice (SL) buffer layer and the growth conditions on AlGaAs/GaAs heterojunction properties such as the interface abruptness and interface roughness. The characterization was performed in a field-emission scanning transmission electron microscope (STEM) and by low temperature photoluminescence (PL). By means of STEM micrographs we find that the abruptness and roughness of quantum wells (QW) with and without SL buffer layer is of equal quality. The dramatically improved PL properties of samples with SL buffer layers show that the impurity density in the active layer is strongly reduced by the SL.

References (12)

Guimar∼aesF.E.G. et al.
J. Crystal Growth
(1991)
KaufmannL.M.F. et al.
J. Crystal Growth
(1988)
HaspekloH. et al.
J. Crystal Growth
(1986)
HeukenM. et al.
IEEE Trans. Electron. Devices ED-33
(1986)
BimbergD. et al.
J. Vacuum Sci. Technol.
(1987)
StobbsW.M. et al.

There are more references available in the full text version of this article.

Cited by (11)

Improved heterointerface quality of V-shaped AlGaAs/GaAs quantum wires characterized by atomic force microscopy and micro-photoluminescence
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The effects of NH₄OH : H₂O₂ : H₂O (=1 : 3 : 50) etching of the initial V-grooved substrate and the use of an AlGaAs/GaAs short-period superlattice buffer layer on improvement of the interface uniformity of V-shaped AlGaAs/GaAs quantum wires (QWRs) were investigated by atomic force microscopy and micro-photoluminescence spectroscopy. We found that the surface roughness on the initial V-grooved substrates induced during V-groove preparation processes could be greatly reduced by the use of the NH₄OH etching treatment. Further, by the combined use of the above two techniques, the QWR interface uniformity could be significantly improved, as revealed by both the elongation of the monolayer step islands formed on the (0 0 1) QWR facet and the suppression of step bunching on the (3 1 1)A QWR facet.
Homogeneity of ZnSSe/ZnSe multiquantum wells grown by metalorganic vapour phase epitaxy
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The ZnS_xSe_1-x (0⩽x⩽1) layers and multiquantum well structures studied here were grown in an atmospheric or in a low-pressure metalorganic vapour phase epitaxy (MOVPE) reactor, respectively. For industrial device production, an excellent homogeneity across the whole wafer is required, so both reactors are equipped with rotating susceptors for two-inch wafers. X-ray diffraction measurements of optimized multiquantum well structures grown with diethylsulphur (DES) in the atmospheric-pressure reactor show very good structural properties and high reproducibility of the layer sequence indicated by sharp satellite peaks and “pendellösung” fringes. Also the near-band-edge photoluminescence (PL) spectrum hints on the excellent layer quality by sharp PL peaks (FWHM= 2.6 meV). The homogeneity of a multiquantum well structure across a two-inch wafer was determined from the local dependence of the PL blue-shift across the wafer. At the edge of the sample grown with H₂S the blue-shift increases, which can be explained by an increased sulphur content or a lower thickness owing to a decreased growth rate. However, Raman measurements taken at samples grown with DES show that the sulphur content is very homogeneous laterally, whereas the variation is much larger in samples grown with H₂S. Homogeneity tests for ZnSSe grown with DES under low pressure or atmospheric pressure show no significant difference. Nevertheless, with H₂S as a sulphur source, the gas phase depletion was reduced at low pressure. With increased gas flow velocity, both the sulphur content and the growth rate homogeneity were improved.
Optimization of strained short-period ZnSSe/ZnSe superlattices grown by metalorganic vapour phase epitaxy
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Series of ZnSe/ZnS_xSe_1-x strained-layer superlattices with x=0.1-0.14 grown by MOVPE using either diethylsulphide (DES) or hydrogen sulphide (H₂S) as the sulphur source have been studied with X-ray double-crystal diffractometry and photoluminescence. The effects of period thickness, number of periods, growth interruption and stabilization of the ZnSSe-to-ZnSe interface as well as buffer layers on the structural and optical properties were determined. These data serve as basis for optimization of the growth parameters. High quality material was obtained as indicated by narrow peak widths and numerous satellite peaks in the X-ray diffraction profiles for optimized samples grown with DES (120 periods, without stabilization, without buffer). Highly efficient blue luminescence at 2.7 eV observed at room temperature confirms the excellent properties of the heterostructures. Because of the high resolution of the double-crystal X-ray diffraction we were enabled to detect very small variations of layer thickness and composition in the superlattice systems.
Improved luminescence from MOVPE-grown GaAs/AlGaAs single quantum wells using a multiple quantum well buffer
1993, Applied Surface Science
The optical properties of various GaAs/AlGaAs single and multiple quantum well (QW) structures grown by metalorganic vapour phase epitaxy, are studied by means of variable temperature (4–295 K) photoluminescence (PL). It is found that the growth of up to 25 periods of AlGaAs/GaAs in a multiple QW structure results in an overall improvement in the 12 K PL response, compared with a single period QW structure. Similarly, single GaAs/AlGaAs QWs grown on top of an AlGaAs/GaAs multiple QW buffer also exhibit superior luminescence properties. The increase in intensity and corresponding decrease in the PL linewidth is explained by the effective trapping at each heterointerface of the diffusing impurities, which appear to originate from the substrate.
Heterostructure field effect transistors grown by MOVPE
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Metalorganic vapor phase epitaxy (MOVPE) has received much attention as an important technique for the growth of III–V compound semiconductor layers for electronic and optoelectronic applications. The move of the AlGaAs/GaAs heterostructure field effect transistor (HFET) technology from research to production will be discussed in this paper. In addition developments such as undoped AlGaAs/GaAs heterostructure insulated gate FET (HIGFET) for digital applications will be reported. These FET offer the possibility of easy production of both n- and p-type channel devices on the same layer structure. The improvements in the performance of electronic devices such as latticematched InP-based n-channel HFET grown by MOVPE will be shown. Especially for p-type structures a reduction in the effective hole mass due to strain causes improvements in the operation of p-type pseudomorphic devices. These InP HFET grown by MOVPE are favorable candidates for the application in high-performance optoelectronic integrated circuits in the 1.1–1.65 μm region.
Optical and electrical properties of the Al<inf>x</inf>Ga<inf>1-x</inf>As/GaAs single heterojunctions grown by low pressure MOVPE
1991, Journal of Crystal Growth
Low temperature photoluminescence (PL) and device transport properties of undoped Al_xGa_1−xAs/GaAs single heterojunctions grown by MOVPE are investigated. The dependence of these properties on the Al contents (0.22⪕x⪕0.52) and growth temperature has been studied. An unusual emission band is observed in the GaAs band-edge spectral region (1.500–1.511 eV) for samples having higher Al concentration. Based on temperature dependent measurements, we assign this emission band to excitons bound either to defects having their origin in residual impurities in the GaAs active layer or to intrinsic defects originated by the introduction of the Al_xGa_1−xAs/GaAs heterojunction.

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Scanning transmission electron microscopy of heterointerfaces grown by metalorganic vapor phase epitaxy (MOVPE)

Abstract

J. Crystal Growth

J. Crystal Growth

J. Crystal Growth

IEEE Trans. Electron. Devices ED-33

J. Vacuum Sci. Technol.