Origins of interfacial disorder in GaSb/InAs superlattices

Thibado, P. M.; Bennett, B. R.; Twigg, M. E.; Shanabrook, B. V.; Whitman, L. J.

doi:10.1063/1.115323

Cited by 28 publications

(17 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[6][7][8][9][10] For example, two different types of interfacial bonds can be formed during the deposition of AlSb on InAs, either AlAs like or InSb like, depending on the III-V deposition sequence. It has been found both experimentally [11][12][13][14] and theoretically 15 that InSblike interfaces are generally more abrupt than those with AlAs-like bonds.…”

Section: Introductionmentioning

confidence: 99%

Structure of InAs/AlSb/InAs resonant tunneling diode interfaces

Nosho¹

1998

Journal of Vacuum Science &Amp; Technology B: Microelectronics and Nanometer Structures Processing, Measurement, and Phenomena

View full text Add to dashboard Cite

We have used in situ plan-view scanning tunneling microscopy to study the surfaces and interfaces within an InAs/AlSb/InAs resonant tunneling diodelike structure grown by molecular beam epitaxy. The nanometer and atomic-scale morphologies of the surfaces have been characterized following a number of different growth procedures. When InAs(001)-(2ϫ4) is exposed to Sb 2 a bilayer surface is produced, with 1 monolayer ͑ML͒ deep ͑3 Å͒ vacancy islands covering approximately 25% of the surface. Both layers exhibit a (1ϫ3)-like reconstruction characteristic of an InSb-like surface terminated with Ͼ1 ML Sb, indicating that there is a significant amount of Sb on the surface. When 5 ML of AlSb is deposited on an Sb-terminated InAs surface, the number of layers observed on each terrace increases to three. Growth of an additional 22 ML of InAs onto the AlSb layer, followed by a 30 s interrupt under Sb 2 , further increases the number of surface layers observed. The root-mean-square roughness is found to increase at each subsequent interface; however, on all the surfaces the roughness is р2 Å. The surface roughness is attributed to a combination of factors, including reconstruction-related stoichiometry differences, kinetically limited diffusion during growth, and lattice-mismatch strain. Possible methods to reduce the roughness are discussed.

show abstract

Section: Introductionmentioning

confidence: 99%

Structure of InAs/AlSb/InAs resonant tunneling diode interfaces

Nosho¹

1998

Journal of Vacuum Science &Amp; Technology B: Microelectronics and Nanometer Structures Processing, Measurement, and Phenomena

View full text Add to dashboard Cite

show abstract

“…2 V. In order to minimize any possible e ects of surface contamination on the superlattice morphology, after examination by STM, each interface was buried under at least 0 . 5 m m of GaSb and the superlattice was regrown up to the next interface of interest (Thibado et al 1995). A STM image of the surface of a typical GaSb bu er layer grown on a GaSb(100) substrate is shown in ® g. 18 (a).…”

Section: Fig 16mentioning

confidence: 99%

“…(Kang et al 1994). Although the dislocation density in the SLs grown on a 1 m m GaSb or InAs bu er layer is less than 10 7´c m -2 , there is still the possibility that dislocations a ect the surface and interface morphologies (Thibado et al 1996). In order to rule out the possible e ects of these dislocations on interfacial disorder, we also grew the SL on GaSb(100) substrates.…”

Section: Fig 13mentioning

confidence: 99%

See 1 more Smart Citation

Interfacial disorder in InAs/GaSb superlattices

wigg¹

1998

Philosophical Magazine A

View full text Add to dashboard Cite

We have addressed the question of interfacial disorder in InAs/GaSb superlattices (SLs) grown by molecular-beam epitaxy using high-resolution transmission electron microscopy, Raman spectroscopy, X-ray di raction, and in-situ scanning tunnelling microscopy (STM). Our analysis indicates that InSblike interfaces have a roughness of 1 monolayer (ML), for a SL grown on a GaSb bu er layer. For GaAs-like interfaces, however, the interface roughness is found to be 2 ML when the SL is grown on a GaSb bu er. For SLs grown on an InAs bu er, the roughness of GaAs-like interfaces (3 ML) is also greater than that of InSb-like interfaces (2 ML). These results suggest two general observations. The ® rst is that GaAs-like interfaces are rougher than InSb-like interfaces. This di erence may be due to the high surface energy of GaAs compared with InSb or to di erences in surface kinetics. These observations are supported by in-situ STM results showing that the growth front surface morphology, for both GaSb and InAs layers, is rougher for GaAs-like interfaces than for InSb-like interfaces. We have also found that interface roughness is greater for an InAs/GaSb SL grown on an InAs bu er layer than for the same SL grown on a GaSb bu er layer. This di erence in interface roughness may arise because InAs SL layers are in tension when grown on a GaSb bu er layer, whereas GaSb SL layers are under compression when grown on an InAs bu er layer. §

show abstract

“…2 Here we describe a sample handling system designed to integrate a modified commercial STM 3 into a multichamber ultrahigh vacuum ͑UHV͒ molecular beam epitaxy ͑MBE͒ facility. The system uses a simple, yet versatile, sample holder design that enables quick and easy sample transfers between multiple chambers, including two Riber MBE and two surface characterization chambers interconnected by Riber UHV ModuTrac™.…”

Section: Performing Organization Name(s) and Address(es)mentioning

confidence: 99%