Volmer‐Weber growth mode of InN quantum dots on GaN by MOVPE

Abstract

The growth of indium nitride quantum dots on c‐plane GaN/sapphire was investigated by metal‐organic vapour phase epitaxy using in situ spectroscopic ellipsometry and ex situ atomic force microscopy. Using an ammonia stabilisation for temperatures above 500 °C desorption of InN structures could be prevented during cool down. At a growth temperature of 520 °C and a trimethylindium partial pressure of 0.5 Pa (V/III ratio of 5000) we observe growth without a wetting layer in the Volmer‐Weber mode, indicated by the presence of InN quantum dots for sub‐monolayer coverages and a constant ratio of quantum dot volume to total InN amount. At this transport limited growth regime the typical quantum dot density of 7 × 1010 cm–2 is independent from coverage. Coalescence occurs after 20 s growth time at an average structure diameter of 51 nm as expected for such a density. Smallest uncapped hexagonal structures are realised with an average diameter of 28 nm and a height of 3.1 nm (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Growth mechanism of InGaN quantum dots during metalorganic vapor phase epitaxy

“…In an earlier work, InN QDs were found to grow according to Volmer-Weber or the 3D island mode [16]. It is therefore not surprising that InGaN QDs on GaN would follow the StranskiKrastanov or 2D to 3D mode, since GaN on GaN grows in the Frank-van der Merwe or the 2D mode.…”

Shape of indium nitride quantum dots and nanostructures grown by metal organic vapour phase epitaxy

“…No metallic indium was found, when the surface is stabilized with ammonia during the cool-down of the sample to below 500 • C [7]. Contact mode AFM measurements show three-dimensional structures.…”

InN Quantum Dots by Metalorganic Chemical Vapor Deposition for Optoelectronic Applications

“…At longer growth times, a linear relationship has been seen between the calculated nominal thickness and growth time (Meissner et al, 2009). As growth time increases, initially both dot height and diameter increase until the diameter stops increasing while the height continues to increase (Meissner et al, 2009;Reilly et al, 2020b). The dot density typically increases sharply in the early stages of dot growth during the nucleation process, up to densities on the order of 10 10 cm −2 (T 550°C; GR of 0.25 Å/s) (Bonef et al, 2020).…”

“…At very short growth times, the calculated nominal thickness from the QDs may not correspond to the expected nominal thickness due to the establishment of a wetting layer (Bonef et al, 2020). At longer growth times, a linear relationship has been seen between the calculated nominal thickness and growth time (Meissner et al, 2009). As growth time increases, initially both dot height and diameter increase until the diameter stops increasing while the height continues to increase (Meissner et al, 2009;Reilly et al, 2020b).…”

“…The dot density typically increases sharply in the early stages of dot growth during the nucleation process, up to densities on the order of 10 10 cm −2 (T 550°C; GR of 0.25 Å/s) (Bonef et al, 2020). At longer growth times, little change occurs in the density as the dots continue to increase in size (Meissner et al, 2009;Reilly et al, 2020b).…”