Defect characterization for epitaxial HgCdTe alloys by electron microscopy

Aoki, Toshihiro; Chang, Yong; Badano, G.; Zhao, Jun; Grein, C. H.; Sivananthan, S.; Smith, David J.

doi:10.1016/j.jcrysgro.2004.01.063

Cited by 43 publications

(33 citation statements)

References 55 publications

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“…54,55 These defects can nucleate at any depth, and occur with different sizes. A summary of an associated nanospectroscopy study was given by Aoki et al 22 Other kinds of voids are caused by dust particles left on the surface by, or in spite of, the substrate cleaning process, such as contaminated deionized water. 39,56,57 Flakes dropping from the chamber wall during growth, substrate mounting, substrate transferring between chambers, and/or from the Hg or other cells can also trigger the formation of voids of any size.…”

Section: Resultsmentioning

confidence: 99%

“…10,22,23 Within a surface crater defect, crystals of both HgCdTe and Te continue to nucleate, with the HgCdTe grains being either semicoherent or incoherent to the Te grains. 10 Energy-dispersive X-ray spectroscopy (EDS) data also confirmed the existence of excessive Te in the surface crater defects (Fig.…”

Section: Resultsmentioning

confidence: 99%

“…Hence Te 2 molecules can trigger the formation of crater void defects on HgCdTe surfaces. 6,22 Although research on defect morphology, crystalline structure, growth conditions, and compositions has been done to explore the formation mechanism of void defects, it is still unclear how the void defects are formed during MBE growth, especially from the viewpoint of crystallography and nucleation. The similarity in morphology of different void defects, including crater defects (or large voids), suggests that there should be certain common physical principles behind their formation.…”

Section: Resultsmentioning

confidence: 99%

“…The TEM measurements have been discussed in detail elsewhere, 10,[22][23][24][25] including the additional steps required to reduce ion-milling damage and preparation artefacts. 25 …”

Section: Methodsmentioning

confidence: 99%

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Surface Morphology and Defect Formation Mechanisms for HgCdTe (211)B Grown by Molecular Beam Epitaxy

Chang

Becker

Grein

et al. 2008

Journal of Elec Materi

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The surface morphology and crystallinity of HgCdTe films grown by molecular beam epitaxy (MBE) on both CdZnTe and CdTe/Si (211)B substrates were characterized using atomic force microscopy (AFM), as well as scanning (SEM) and transmission (TEM) electron microscopy. Crosshatch patterns and sandybeach-like morphologies were commonly found on MBE (211) HgCdTe epilayers grown on both CdZnTe and CdTe/Si substrates. The patterns were oriented along the 213 Â Ã , 231 Â Ã , and 011 Â Ã directions, which were associated with the intersection between the (211) growth plane and each of the eight equivalent HgCdTe slip planes. This was caused by strain-driven operation of slip in these systems with relative large Schmid factor, and was accompanied by dislocation formation as well as surface strain relief. Surface crater defects were associated with relatively high growth temperature and/or low Hg flux, whereas microtwins were associated with relatively low growth temperature and/or high Hg flux. AFM and electron microscopy were used to reveal the formation mechanisms of these defects. HgCdTe/HgCdTe superlattices with layer composition differences of less than 2% were grown by MBE on CdZnTe substrates in order to clarify the formation mechanisms of void defects. The micrographs directly revealed the spiral nature of growth, hence demonstrating that the formation of void defects could be associated with the Burton, Cabrera, and Frank (BCF) growth mode. Void defects, including microvoids and craters, were caused by screw defect clusters, which could be triggered by Te precipitates, impurities, dust, other contamination or flakes. Needle defects originated from screw defect clusters linearly aligned along the 011 Â Ã directions with opposite Burgers vector directions. They were visible in HgCdTe epilayers grown on interfacial superlattices. Hillocks were generated owing to twin growth of void or needle defects on (111) planes due to low growth temperature and the corresponding insufficient Hg movement on the growth surface. Therefore, in addition to nucleation and growth of HgCdTe in the normal two-dimensional layer growth mode, the BCF growth mode played an important role and should be taken into account during investigation of HgCdTe MBE growth mechanisms.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

“…The TEM measurements have been discussed in detail elsewhere, 10,[22][23][24][25] including the additional steps required to reduce ion-milling damage and preparation artefacts. 25 …”

Section: Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Surface Morphology and Defect Formation Mechanisms for HgCdTe (211)B Grown by Molecular Beam Epitaxy

Chang

Becker

Grein

et al. 2008

Journal of Elec Materi

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“…7 ACEMs, which are capable of pushing information limits to beyond the 1.0-Å level, have since become available, so that projected atomic columns can be resolved in all zincblende compound semiconductors for observation in this viewing direction. 8 Specimen damage during the process of ion milling is well known to be a problematic issue when preparing cross-sections of II-VI semiconductors for TEM observation, and can easily lead to erroneous interpretation of defect microstructure; 9 For example, argon-ion milling was shown to cause {111}-type stacking-fault dislocation loops, which could however be effectively eliminated by instead using reactive iodine milling (albeit also accompanied by greatly increased damage to components of the vacuum system). 10 In the case of HgCdTe alloys, it was shown that the amount of ion-induced damage could be markedly reduced by milling at low glancing angles and with lower-energy (<2 keV) ion beams, and with the sample cooled to liquid-nitrogen temperature.…”

Section: Introductionmentioning

confidence: 99%

Atomic-Scale Characterization of II–VI Compound Semiconductors

Smith

2013

Journal of Elec Materi

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Alloys of II-VI compound semiconductors with suitable band gap selection potentially provide broad coverage of wavelengths for photodetector applications. Achievement of high-quality epitaxial growth is, however, essential for successful development of integrated photonic and optoelectronic devices. Atomic-scale characterization of structural defects in II-VI heterostructures using electron microscopy plays an invaluable role in accomplishing this goal. This paper reviews some recent high-resolution studies of II-VI compound semiconductors with zincblende crystal structure, as grown epitaxially on commonly used substrates. Exploratory studies using aberration-corrected electron microscopes are also briefly considered.

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Definitive Molecular Level Characterization of Defects in UiO‐66 Crystals

et al. 2015

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The identification and characterization of defects, on the molecular level, in metal‐organic frameworks (MOFs) remain a challenge. With the extensive use of single‐crystal X‐ray diffraction (SXRD), the missing linker defects in the zirconium‐based MOF UiO‐66, Zr6O4(OH)4(C8H4O4)6, have been identified as water molecules coordinated directly to the zirconium centers. Charge balancing is achieved by hydroxide anions, which are hydrogen bonded within the pores of the framework. Furthermore, the precise nature of the defects and their concentration can be manipulated by altering the starting materials, synthesis conditions, and post‐synthetic modifications.

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Defect characterization for epitaxial HgCdTe alloys by electron microscopy

Cited by 43 publications

References 55 publications

Surface Morphology and Defect Formation Mechanisms for HgCdTe (211)B Grown by Molecular Beam Epitaxy

Surface Morphology and Defect Formation Mechanisms for HgCdTe (211)B Grown by Molecular Beam Epitaxy

Atomic-Scale Characterization of II–VI Compound Semiconductors

Definitive Molecular Level Characterization of Defects in UiO‐66 Crystals

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