Insights into the growth mechanism of InxGa1−xN epitaxial nanostructures formed using a silane predose

The Use of Spatial Analysis Techniques in Defect and Nanostructure Studies

“…The growth conditions of the samples used in the investigation of InGaN QDs produced on the surface of GaN films using a SiH 4 predose are described in Ref. 8, and the growth conditions of the samples used in the investigation of In droplets on InAlN films are described in Ref. 23.…”

“…Longer SiH 4 predose times and/or longer QD growth times were found to produce higher QD densities. 8 The precise role of the SiH 4 pretreatment is under debate; while Si was initially thought to act as a surfactant, 31 subsequent studies indicated that it may produce a SiN x layer that acts as a holey ''nanomask,'' 32,33 while others suggested that its role in inducing surface roughening of the GaN was more important. 34 The QDs in samples with the lowest QD densities of 6 9 10 10 cm À2 displayed a spatially random pattern of nucleation (Fig.…”

“…The presence of spatial uniformity seems inconsistent with nucleation through randomly located holes in a SiN x nanomask, a conclusion supported by other evidence from cross-sectional high-resolution TEM, in which no SiN x nanomask can be observed. 8 However, since the nature and mechanism of formation of any possible nanomask is not well understood, it is difficult to draw definite conclusions from the spatial analysis data.…”

“…4,5 Semiconductor nanostructures such as quantum dots (QDs) are also of interest for applications in devices such as light-emitting diodes (LEDs) and laser diodes (LDs). [6][7][8][9] However, although the types and densities of defects and nanostructures are frequently quoted in the literature, information regarding their spatial distribution is rarely reported. This is unfortunate, as such information can be of considerable value.…”

Growth and optical characterisation of multilayers of InGaN quantum dots

“…Whilst self-assembled InGaN QDs have been grown by molecular beam epitaxy (MBE) via Stranski-Krastanov (SK) growth [7], there are a number of different methods to grow InGaN QDs in metalorganic vapour phase epitaxy (MOVPE), such as pre-treatment of the surface by a silicon precursor [8], and growing InGaN thin films at two different temperatures [9]. Our approach for the growth of InGaN QDs (modified droplet epitaxy) involves a post-growth anneal of the InGaN epilayer at the growth temperature in molecular nitrogen [10].…”