Effect of MOVPE growth conditions on AlN films on annealed sputtered AlN templates with nano-striped patterns

Al- and N-polar AlN have been grown by metalorganic vapor phase epitaxy (MOVPE) with the assistance of In dopant and characterized by in situ interferometry, ellipsometry, scanning electron microscopy, atomic force microscopy, and X-ray diffractometry. The growth of Al-polar AlN is faster with smoother surfaces than the N-polar ones, which is explained by theoretical calculations. The surfactant effect of In is confirmed by improving the growth rate and surface flatness without getting into the epilayer. Additionally, In is also favorable for reducing the density of dislocations and improving the crystalline quality, especially that of Al-polar AlN. The results suggest that using In surfactant to grow the Al-polar AlN epilayer leads to a better crystal quality under proper pre-growth treatments, low- and high-temperature AlN growth conditions.

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Engineering Dislocation Dynamics in Inx(AlyGa1−y)1−xP Graded Buffers Grown on Gap by Movpe

MRS Proceedings ◽

10.1557/proc-510-131 ◽

1998 ◽

Vol 510 ◽

Cited By ~ 5

Author(s):

A.Y. Kim ◽

E.A. Fitzgerald

Keyword(s):

Surface Roughness ◽

Dislocation Density ◽

Growth Conditions ◽

Dislocation Nucleation ◽

Dislocation Dynamics ◽

Threading Dislocation ◽

High Quality ◽

Movpe Growth ◽

Threading Dislocation Density ◽

Buffer Design

AbstractTo engineer high-quality Inx(AlyGa1−y)1−x P/Ga1−xP graded buffers, we have explored the effects of graded buffer design and MOVPE growth conditions on material quality. We demonstrate that surface roughness causes threading dislocation density (TDD) to increase with continued grading: dislocations and roughness interact in a recursive, escalating cycle to form pileups that cause increasing roughness and dislocation nucleation. Experiments show that V/III ratio, temperature, and grading rate can be used to control dislocation dynamics and surface roughness in InxGa1−xP graded buffers. Control of these parameters individually has resulted in x = 0.34 graded buffers with TDD = 5 × 106 cm−2and roughness = 15 nm and a simple optimization has resulted in TDD = 3 × 106 cm −2and roughness = 10 un. Our most recent work has focused on more sophisticated optimization and the incorporation of aluminum for x > 0.20 to keep the graded buffer completely transparent above 545 nm. Given our results, we expect to achieve transparent, device-quality Inx(AlyGa1−y)1−x P/GaP graded buffers with TDD < 106 cm−2

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High-Quality InGaAsP Crystals Grown by MOVPE Using TBA and TBP

MRS Proceedings ◽

10.1557/proc-216-365 ◽

1990 ◽

Vol 216 ◽

Author(s):

A. Kuramata ◽

S. Yasmazaki ◽

K. Nakajima

Keyword(s):

Optical Properties ◽

Growth Conditions ◽

Band Edge Emission ◽

Photoluminescence Spectra ◽

Edge Emission ◽

High Quality ◽

Electrical And Optical Properties ◽

Group V ◽

Movpe Growth ◽

The Relationship

ABSTRACTTBA and TBP are attractive candidates for group V sources for MOVPE growth from the viewpoint of safety. We studied how the composition of InGaAsP crystals depends on growth conditions, and investigated its electrical and optical properties. The relationship between group V sources and crystals indicates that TBA and TBP decompose into AsH and PH. Since there is no carbon in AsH and PH, carbon contamination in the crystals is expected to be small. Carrier concentrations ranged from 5×1014 cm−3 to 1.5×1015 cm−3. Photoluminescence spectra at 4.2K showed strong band-edge emission with no acceptor-related emission. Based on the electrical and optical properties of the crystals, we conclude that high-quality InGaAsP crystals can be grown using TBA and TBP.

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Effects of MOVPE Growth Conditions on GaN Layers Doped with Germanium

10.20944/preprints202012.0678.v1 ◽

2020 ◽

Author(s):

Dario Schiavon ◽

Elżbieta Litwin-Staszewska ◽

Rafał Jakieła ◽

Szymon Grzanka ◽

Piotr Perlin

Keyword(s):

Growth Rate ◽

High Temperature ◽

Low Temperature ◽

Surface Morphology ◽

Growth Temperature ◽

High Growth ◽

Growth Conditions ◽

High Growth Rate ◽

Pit Formation ◽

Movpe Growth

The effect of growth temperature and precursor flows on the doping level and surface morphology of Ge-doped GaN layers was researched. The results show that germanium is more readily incorporated at low temperature, high growth rate and high V/III ratio, thus revealing a similar behavior to what was previously observed for indium. V-pit formation can be blocked at high temperature but also at low V/III ratio, the latter of which however causing step bunching.

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