Size-Limiting Effect of Site-Controlled InAs Quantum Dots Grown at High Temperatures by Molecular Beam Epitaxy

Abstract

We have investigated the site-controlled growth of InAs quantum dots (QDs) by using atomic-force-microscope (AFM)-assisted anodic oxidation. It is found that the morphology of the site-controlled QDs strongly depends on the growth temperature, T g ; when QDs are grown at T g 480 C, the obtained QDs are much larger than the nanoholes prepared by AFM oxidation. In contrast, when QDs are grown at T g ¼ 520 C, the diameter of the QDs is limited by that of nanoholes and is almost unchanged with varying InAs supply. The single-layer QD array grown at 520 C showed good optical properties and uniformities. #

Precise Arrays of Epitaxial Quantum Dots Nucleated by In Situ Laser Interference for Quantum Information Technology Applications

“…These results are comparable to those reported results of high-quality self-assembled InAs QDs with a low growth rate . A very narrow line width of 22 meV for the GS peak is observed at low power, which is smaller than most values previously reported by using other nanopatterning technologies. − It appears that the size variation in these dots is reasonably small, indicating their good crystalline quality. This suggests that the laser interference does not degrade the optical quality of the QDs and this observation may enable the implementation of optically efficient quantum devices using this scheme.…”

Study of Growth Parameters for Single InAs QD Formation on GaAs(001) Patterned Substrates by Local Oxidation Lithography

“…Different lithographic techniques have been demonstrated as suitable for the fabrication of nanohole patterned substrates, including e-beam lithography, − nanoimprint lithography or laser interference lithography . Other techniques such as focus ion beam (FIB) patterning and atomic force microscopy (AFM) oxidation lithography − have also been developed.…”

“…In this work, we use GaAs(001) patterned substrates fabricated by AFM local oxidation lithography as templates for growth of site-controlled InAs QDs. This lithography technique has been demonstrated as a powerful tool for substrate patterning. − It provides high positioning accuracy, and it is very promising in novel strategies for deterministic integration of single nanostructures in photonic cavities , for future quantum information applications. Here, we report on the influence of two main parameters during growth by molecular beam epitaxy (MBE), namely, substrate temperature and As 4 overpressure, on the InAs nucleation process within patterned nanoholes.…”

Role of re-growth interface preparation process for spectral line-width reduction of single InAs site-controlled quantum dots

“…The selectivity arises from the local minima of the surface chemical potential located at the bottom of each nanohole, related to the local curvature, which drives adatom migration towards the nanoholes [8]. Several lithographic techniques have been used for the fabrication of patterned substrates with application in growth of site-controlled quantum dots (SCQDs), including e-beam lithography [9][10][11][12][13], nanoimprint lithography (NIL) [14,15] and atomic force microscopy (AFM) oxidation lithography [16,18]. AFM oxidation lithography enables the direct patterning of the substrates (without the use of resists), provides high positioning accuracy and is a very promising lithographic technique for the deterministic integration of nanostructures in photonic microcavities and devices [19,20].…”