Role of strain in growth kinetics of AlGaN layers during plasma-assisted molecular beam epitaxy

Влияние параметров нитридизации и начальных ростовых условий на полярность эпитаксиальных слоев GaN, выращенных молекулярно-пучковой эпитаксией с плазменной активацией азота на подложках Si(111)

“…Та-ким образом, оказалось невозможным установить взаимосвязь между режимом нитридизации кремниевой подложки и кристаллографической полярностью эпитаксиального слоя GaN. Однако, согласно [9,10], температура подложки Si(111) в процессе нитридизации влияет на морфологию буферного слоя Si x N y . Он может быть аморфным при осуществлении " низкотемпературной" и кристаллическим в случае " высокотемпературной" нитридизации.…”

HVPE growth of AlXGa1-XN templates for UV-LED applications

“…There are many processes to prepare the Al x Ga 1-x N compounds including metal-organic chemical deposition (MOCVD), [5][6][7][8][9][10][11][12][13] pulsed laser deposition (PLD), 14 molecular beam epitaxy (MBE), [15][16][17] and halide vapor phase epitaxy (HVPE). [18][19][20][21][22][23] Among these processes, MOCVD has been regarded as a chief apparatus for the commercial fabrication of LEDs.…”

RHEED monitoring of elastic stresses during MBE growth of group III nitride heterostructures

“…However, these device heterostructures are almost always subject to the development of elastic stresses, which is related to a considerable lattice mismatch (up to and above 10%) between layers with different compositions and the absence of commercially available homoepitaxial sub strates. The presence of elastic stresses of different signs significantly influences both the kinetics of epi taxial growth and the energy band diagrams of both materials and device heterostructures [2,3]. In addi tion, relaxation of these stresses can proceed with the formation of various extended defects (e.g., threading dislocations with a density of up to 10 10 cm -2 ) and/or with a change in the morphology of growing layers, which can significantly influence the device charac teristics.…”

“…Although digital processing of RHEED data was originally used as long ago as in 1991 [9], there are rather few research groups (see, e.g., [10]) at present using computer aided RHEED for the analysis of strain relaxation in III N heterostructures. This situa tion is apparently related to methodological problems encountered in this analysis.The present Letter describes a new method devel oped for the statistical analysis of RHEED patterns and demonstrates the results of its application to quantitative monitoring of the crystal lattice parame ter in heterostructures based on various binary and ter nary III N compounds in the course of their MBE growth.The samples of III N heterostructures were grown on c Al 2 O 3 substrates by plasma assisted MBE (PAMBE) using the nitrogen plasma activa tor [2,11]. We have studied the growth of (i) het erostructures based on binary InN/GaN, GaN/AlN, and AlN/GaN (~1 μm/2 μm) layers with various surface morphologies and (ii) short period superlattices {GaN (4 nm)/AlN(6 nm)} 30 on an ~700 nm thick AlN buffer layer.…”

“…The samples of III N heterostructures were grown on c Al 2 O 3 substrates by plasma assisted MBE (PAMBE) using the nitrogen plasma activa tor [2,11]. We have studied the growth of (i) het erostructures based on binary InN/GaN, GaN/AlN, and AlN/GaN (~1 μm/2 μm) layers with various surface morphologies and (ii) short period superlattices {GaN (4 nm)/AlN(6 nm)} 30 on an ~700 nm thick AlN buffer layer.…”