Characterization of lateral correlation length of interface roughness in MBE grown GaAs/AlAs quantum wells by mobility measurement

We present a theoretical study of the effect from doping of quantum wells (QWs) on enhancement of the mobility limited by one-interface roughness scattering. Within the variational approach, we introduce the enhancement factor defined by the ratio of the overall mobility in symmetric two-side doped square QWs to that in the asymmetric one-side counterpart under the same doping and interface profiles. The enhancement is fixed by the sample parameters such as well width, sheet carrier density, and correlation length. So, we propose two-side doping as an efficient way to upgrade the quality of QWs. The two-interface roughness scattering is also incorporated to make comparison.

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Cathodoluminescence characterization of two-dimensional interface structure of quantum wells

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100176903 ◽

1990 ◽

Vol 48 (4) ◽

pp. 754-755

Author(s):

Kazumi Wada

Keyword(s):

Quantum Wells ◽

Optical Transition ◽

Two Dimensions ◽

Interface Roughness ◽

Luminescence Spectroscopy ◽

Two Dimensional ◽

Quantum Well Structures ◽

Interface Structures ◽

Nondestructive Characterization

Exotic properties shown by quantum well structures, typical structures of future electron devices, are sensitive to interface roughness. Extensive studies are, thus, focused on characterization of interface structures. Recent improvement in quantum wire fabrication technology demands for characterizing not only perpendicular-interfaces to the growth direction but also parallel-ones (sidewall-interfaces). Such sophistication needs innovation in two-dimensional and nondestructive characterization technology.In device structures, interfaces are generally located deep in bulk. STM which visualize surface atoms can not monitor such interface. It is, thus, difficult to two- dimensionally characterize the interfaces.Interface steps induce well width fluctuation, which modulates optical transition energy between ground subbands in conduction and valence bands. Thus, interface step structures can be characterized by luminescence spectroscopy. Cathodoluminescence basically meets demand for nondestructive characterization of interface structures in two dimensions.

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Quantitative characterization of the interface roughness of (GaIn)As quantum wells by high resolution STEM

Micron ◽

10.1016/j.micron.2015.07.003 ◽

2015 ◽

Vol 79 ◽

pp. 1-7 ◽

Cited By ~ 5

Author(s):

H. Han ◽

A. Beyer ◽

K. Jandieri ◽

K.I. Gries ◽

L. Duschek ◽

...

Keyword(s):

High Resolution ◽

Quantum Wells ◽

Interface Roughness ◽

Quantitative Characterization

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Interface-Related In-Plane Optical Anisotropy of Quantum Wells Studied by Reflectance-Difference Spectroscopy

Materials Science Forum ◽

10.4028/www.scientific.net/msf.475-479.1777 ◽

2005 ◽

Vol 475-479 ◽

pp. 1777-1782

Author(s):

Y.H. Chen ◽

X.L. Ye ◽

Bo Xu ◽

Yi Ping Zeng ◽

Z.G. Wang

Keyword(s):

Quantum Wells ◽

Optical Anisotropy ◽

Interface Roughness ◽

Difference Spectroscopy ◽

Quantum Well Structures ◽

Semiconductor Interfaces ◽

Atomic Segregation ◽

Reflectance Difference Spectroscopy ◽

Transition Index

The in-plane optical anisotropy of three groups of GaAs/AlGaAs quantum well structures has been studied by reflectance-difference spectroscopy (RDS). For GaAs/Al0.36Ga0.64As single QW structures, it is found that the optical anisotropy increases quickly as the well width is decreased. For an Al0.02Ga0.98As/AlAs multiple QW with a well width of 20nm, the optical anisotropy is observed not only for the transitions between ground states but also for those between the excited states with transition index n up to 5. An increase of the anisotropy with the transition energy, or equivalently the transition index n, is clearly observed. The detailed analysis shows that the observed anisotropy arises from the interface asymmetry of QWs, which is introduced by atomic segregation or anisotropic interface roughness formed during the growth of the structures. More, when the 1 ML InAs is inserted at one interface of GaAs/AlGaAs QW, the optical anisotropy of the QW can be increased by a factor of 8 due to the enhanced asymmetry of the QW. These results demonstrate clearly that the RDS is a sensitive and powerful tool for the characterization of semiconductor interfaces.

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Characterization of GaAs/AlGaAs quantum wells and quantum wires by chemical lattice imaging

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100171419 ◽

1994 ◽

Vol 52 ◽

pp. 736-737

Author(s):

A. Carlsson ◽

J.-O. Malm ◽

A. Gustafsson

Keyword(s):

Quantum Well ◽

Quantum Wells ◽

Quantum Wires ◽

Vapour Phase ◽

Quantitative Information ◽

Lattice Imaging ◽

Vapour Phase Epitaxy ◽

Metalorganic Vapour Phase Epitaxy ◽

High Resolution Images

In this study a quantum well/quantum wire (QW/QWR) structure grown on a grating of V-grooves has been characterized by a technique related to chemical lattice imaging. This technique makes it possible to extract quantitative information from high resolution images.The QW/QWR structure was grown on a GaAs substrate patterned with a grating of V-grooves. The growth rate was approximately three monolayers per second without growth interruption at the interfaces. On this substrate a barrier of nominally Al0.35 Ga0.65 As was deposited to a thickness of approximately 300 nm using metalorganic vapour phase epitaxy . On top of the Al0.35Ga0.65As barrier a 3.5 nm GaAs quantum well was deposited and to conclude the structure an additional approximate 300 nm Al0.35Ga0.65 As was deposited. The GaAs QW deposited in this manner turns out to be significantly thicker at the bottom of the grooves giving a QWR running along the grooves. During the growth of the barriers an approximately 30 nm wide Ga-rich region is formed at the bottom of the grooves giving a Ga-rich stripe extending from the bottom of each groove to the surface.

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