Band edge thermometry for the MBE growth of (Hg,Cd)Te-based materials

Schlereth, Raimund; Hajer, J.; Fürst, Lena; Schreyeck, S.; Buhmann, H.; Molenkamp, Laurens W.

doi:10.1016/j.jcrysgro.2020.125602

Cited by 11 publications

(5 citation statements)

References 7 publications

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“…In the III-V chamber, Ga is supplied for 2 min at a beam equivalent pressure of about 4 × 10 −8 mbar from an effusion cell at a substrate temperature of 250 • C. Solid-state diffusion of Ga into the Au disks results in the formation of Au-Ga alloy droplets with a melting temperature of about 350 • C. Upon transferral into the II-VI chamber, the substrates are heated in a stabilizing Zn flux to the growth temperature of 440-450 • C, well above the melting point of the Au-Ga alloy. The temperature is monitored by band edge thermometry [9,10], which allows us to adjust the temperature of the substrate surface with high precision and reliability. ZnTe nanowires are grown using beam-equivalent pressures in the range of 1-2 × 10 −6 mbar and a Zn : Te ratio of 0.6-0.7 at a constant substrate temperature.…”

Section: Methodsmentioning

confidence: 99%

Selective area grown ZnTe nanowires as the basis for quasi-one-dimensional CdTe-HgTe multishell heterostructures

Hajer

Mantei

Kessel

et al. 2020

Phys. Rev. Materials

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Selective area growth is employed in the vapor-liquid-solid molecular beam epitaxy of ZnTe nanowire arrays. Full control over the location of the individual nanowires is achieved by defined positioning of the growth catalyst. This study addresses the influence of substrate material and growth temperature on the yield of vertical nanowires. The optimized procedure provides arrays of single-crystalline free-standing nanowires with a high ensemble uniformity. The nanowires exhibit a uniform shape with a diameter of about 80 nm and reach a length of more than 3 μm, which makes them suitable as substrates for core-shell nanowires of the topological insulator material HgTe.

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Section: Methodsmentioning

confidence: 99%

Selective area grown ZnTe nanowires as the basis for quasi-one-dimensional CdTe-HgTe multishell heterostructures

Hajer

Mantei

Kessel

et al. 2020

Phys. Rev. Materials

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“…Even an insignificant deviation of temperature from the optimum value may give rise to imperfections of the crystal structure: formation of threading defects [10], disengagement of phases of different composition [11], development of roughness of the growth surface [6], and other unwanted effects. Temperature monitoring in the process of growth is a highly topical problem in CMT MBE technology and attracts considerable attention [12][13][14][15][16][17][18]. In addition to affecting the epitaxy process, uncontrolled temperature variation makes it difficult to determine the composition accurately using the ellipsometry method.…”

Section: Introductionmentioning

confidence: 99%

In situ ellipsometric monitoring of composition and temperature of HgCdTe layers during their growth

et al. 2022

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An ellipsometric technique has been developed which makes it possible to observe changes in the composition and temperature of cadmium--mercury--tellurium layers during their growing by molecular beam epitaxy. The technique was tested for diagnostics the variations of the composition and the temperature during layer growth in the mode of constant power of the substrate heater and with its sharp change. It was found that the drop in power and a following decrease in the growth temperature were also accompanied by a monotonic decrease in the composition. In the case of a constant heater power, a slight increase in the sample temperature was observed with an almost unchanged composition of the growing layer. Keywords: ellipsometry, mercury--cadmium--telluride, in situ control, epitaxial growth, temperature.

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“…В значительной мере это касается контроля технологических процессов молекулярно-лучевой эпитаксии (МЛЭ) гетероструктур на основе теллуридов кадмия и ртути (КРТ). Эллипсометрия используется для определения состава слоeв в процессе роста [1][2][3][4][5], их структурного совершенства [6,7], скорости роста [6,8], температуры ростовой поверхности [9][10][11]. Проблема измерения температуры в условиях сложного лучистого теплообмена является непростой задачей и крайне актуальна для низкотемпературного синтеза слоeв КРТ.…”

Section: Introductionunclassified

Исследование температурной зависимости спектров оптических постоянных пленок Hg-=SUB=-1-x-=/SUB=-Cd-=SUB=-x-=/SUB=-Te, выращенных методом молекулярно-лучевой эпитаксии

Швец¹,

Marin²,

Якушев³

et al. 2021

Оптика И Спектроскопия

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На основе проведeнных in situ и ex situ эллипсометрических измерений найдены спектральные зависимости температурной чувствительности оптических постоянных Hg1-xCdxTe --- dn(λ) и dk(λ) для серии образцов разного состава в диапазоне от 0.160 до 0.327. Эксперименты были проведены в процессе остывания выращенных образцов в вакуумной камере. Установлено, что полученные зависимости dn и dk хорошо аппроксимируются суммой трeх осцилляторов Лоренца с добавлением дисперсионных слагаемых формулы Коши. Предложена параметрическая модель, которая описывает чувствительности dn(λ) и dk(λ) для произвольного состава x в указанном диапазоне вблизи температуры роста. Проведенные ex situ температурные измерения вблизи комнатной температуры коррелируют с данными высокотемпературных измерений. Полученные результаты актуальны для разработки эллипсометрических методов контроля in situ процессов роста слоeв Hg1-xCdxTe. Ключевые слова: кадмий-ртуть-теллур, эллипсометрия, спектры оптических констант, температурная чувствительность, молекулярно-лучевая эпитаксия.

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Band edge thermometry for the MBE growth of (Hg,Cd)Te-based materials

Cited by 11 publications

References 7 publications

Selective area grown ZnTe nanowires as the basis for quasi-one-dimensional CdTe-HgTe multishell heterostructures

Selective area grown ZnTe nanowires as the basis for quasi-one-dimensional CdTe-HgTe multishell heterostructures

In situ ellipsometric monitoring of composition and temperature of HgCdTe layers during their growth

Исследование температурной зависимости спектров оптических постоянных пленок Hg-=SUB=-1-x-=/SUB=-Cd-=SUB=-x-=/SUB=-Te, выращенных методом молекулярно-лучевой эпитаксии

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