The growth rate evolution versus substrate temperature and V/III ratio during GaN MBE using ammonia

Alexeev, A. N.; Borisov, B.; Chaly, V. P.; Demidov, D. M.; Dudin, A. L.; Krasovitsky, D. M.; Pogorelsky, Yu. V.; Shkurko, A. P.; Соколов, И. А.; Stepanov, M. V.; Ter-Martirosyan, A. L.

doi:10.1557/s1092578300000624

Cited by 82 publications

(4 citation statements)

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“…Therefore, the optimum GaN growth temperature can be determined as a threshold value corresponding to a temperature approaching the GaN thermal decomposition temperature. [33][34][35] In our experiment, for an NH 3 flow of 100 cm 3 min −1 , this temperature was determined to be T g = 945 °C, and these conditions were used for the growth of the AlGaN buffer as well as the barrier layers.…”

Section: Growth Of Hemt Heterostructures and Their 2deg Propertiesmentioning

confidence: 99%

AlGaN/GaN high electron mobility transistor heterostructures grown by ammonia and combined plasma-assisted ammonia molecular beam epitaxy

Alyamani

Луценко²,

Rzheutski³

et al. 2019

Jpn. J. Appl. Phys.

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The structural properties and surface morphology of AlN epitaxial layers grown by ammonia (NH3) and plasma-assisted (PA) molecular beam epitaxy (MBE) at different growth conditions on (0001) sapphire were investigated. The lowest RMS roughness of ∼0.7 nm was achieved for the sample grown by NH3 MBE at a substrate temperature of 1085 °C and NH3 flow of 100 standard cm3 min−1. Atomic force microscopy measurements demonstrated a terrace-monolayer step-like surface morphology. Furthermore, the optimal substrate temperature for growth of GaN and AlGaN layers was determined from analysis of the GaN thermal decomposition rate. Using the optimized growth conditions, high electron mobility transistor heterostructures were grown by NH3 MBE on different types of AlN nucleation layer deposited by NH3 MBE or PA MBE. The grown heterostructures demonstrated comparable two-dimensional electron gas (2DEG) properties. The maximum 2DEG mobility of ∼2000 cm2 V–1 s–1) at a 2DEG density of ∼1.17 × 1013 cm−2 was achieved for the heterostructure with a PA MBE-grown AlN nucleation layer. The obtained results demonstrate the possibility of successful combination of different epitaxial approaches within a single growth process, which will contribute to the development of a new type of hybrid epitaxy that exploits the advantages of several technologies.

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Section: Growth Of Hemt Heterostructures and Their 2deg Propertiesmentioning

confidence: 99%

AlGaN/GaN high electron mobility transistor heterostructures grown by ammonia and combined plasma-assisted ammonia molecular beam epitaxy

Alyamani

Луценко²,

Rzheutski³

et al. 2019

Jpn. J. Appl. Phys.

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“…Температура роста слоев AlGaN в серии варьировалась от 860 до 950 °С. Известно, что шероховатость поверхности и скорость роста слоев GaN чувствительны к температуре роста вследствие влияния термического разложения GaN [8,9] Влияние температуры роста на локализацию неравновесных носителей в слоях AlGaN исследовалось путем измерения стоксова сдвига, который определялся как энергетический зазор между положением полосы ФЛ и краем поглощения, оцененного по спектру пропускания [10]. Полученные результаты приведены на рис.…”

Section: методика проведения экспериментаunclassified

AMMONIA MOLECULAR BEAM EPITAXY OF AlGaN HETEROSTRUCTURES ON SAPPHIRE SUBSTRATES

Rzheutskii¹,

Соловьев²,

Voinilovich³

et al. 2019

Doklady Belorusskogo gosudarstvennogo universiteta informatiki

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In order to develop a technology for the growth of Al(Ga)N-based heterostructures, the effect of different molecular beam epitaxy growth conditions on the properties of AlN and AlGaN layers was studied. The optimal conditions for the growth of AlN buffer layers were established, which made it possible to achieve a root mean square roughness as small as 0.7 nm. It was shown that an increase of AlN layer thickness leads to a decrease of density of edge dislocations, while no explicit dependence of the screw dislocation density on the layer thickness was observed. The minimal obtained dislocations density values for 1.25μm-thick AlN layer were n edges = 5.9×10 9 cm −2 and n screw = 2.2×10 7 cm −2 for edge and screw dislocations respectively. As a result of optimization of the AlGaN growth temperature, a series of 0.15μm-thick layers was grown, which showed stimulated emission at wavelengths λ = 330 nm, 323 nm, 303 nm, and 297 nm with threshold power densities of 0.7 MW/cm 2 , 1.1 MW/cm 2 , 1.4 MW/cm 2 and 1.4 MW/cm 2 , respectively. The determined optimal epitaxy conditions for AlN and AlGaN layers were used to grow the AlGaN/GaN high electron mobility transistor structure on a sapphire substrate with two-dimensional electron gas, which had a mobility of 1950 cm 2 /(V s) at a concentration of 1.15×10 13 cm-2. The obtained results are important for creating of nitride-based UV-emitting optoelectronic semiconductor devices, as well as high-power and high-frequency electronic devices.

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“… 29 It is well-known that critical parameters in all MBE growth processes are the III/V elements ratio and substrate temperature. Many studies showed that temperature has a vital influence on the crystal quality and surface roughness 30 , 31 and on defect states and stress relaxation. 32 MBE growth of GaN at high temperatures leads to 2D layer-by-layer growth and a smooth surface.…”

Section: Introductionmentioning

confidence: 99%