On the mechanisms of spontaneous growth of III-nitride nanocolumns by plasma-assisted molecular beam epitaxy

Ristic, Jelena and Calleja Pardo, Enrique and Fernández-Garrido, Sergio and Trampert, Achim and Cerutti, Laurent and Jahn, U. and Ploog, K.H. (2008). On the mechanisms of spontaneous growth of III-nitride nanocolumns by plasma-assisted molecular beam epitaxy. "Journal of Crystal Growth", v. 310 (n. 18); pp. 4035-4045. ISSN 0022-0248. https://doi.org/10.1016/j.jcrysgro.2008.05.057.

Description

Title: On the mechanisms of spontaneous growth of III-nitride nanocolumns by plasma-assisted molecular beam epitaxy
Author/s:
  • Ristic, Jelena
  • Calleja Pardo, Enrique
  • Fernández-Garrido, Sergio
  • Trampert, Achim
  • Cerutti, Laurent
  • Jahn, U.
  • Ploog, K.H.
Item Type: Article
Título de Revista/Publicación: Journal of Crystal Growth
Date: August 2008
ISSN: 0022-0248
Volume: 310
Subjects:
Freetext Keywords: A1. Low-dimensional structures; A1. Nanostructures; A2. Growth models; A3. Molecular beam epitaxy; B1. Nitrides; B2. Semiconducting III–V materials
Faculty: E.T.S.I. Telecomunicación (UPM)
Department: Ingeniería Electrónica
Creative Commons Licenses: Recognition - No derivative works - Non commercial

Full text

[img]
Preview
PDF - Requires a PDF viewer, such as GSview, Xpdf or Adobe Acrobat Reader
Download (4MB) | Preview

Abstract

A study of the GaN nanocolumns nucleation and growth by molecular beam epitaxy on Si(1 1 1) is presented. Ga droplets with different diameters (340–90 nm) were deposited on the substrate, prior to growth, to determine any effect on the nanocolumns size and distribution. Results indicate that there is no difference in nanocolumnar size and density whether Ga droplets are used or not, meaning that Ga droplets do not act as catalysts for the nanocolumns nucleation. In addition, Ga droplets were never observed on the nanocolumn tips upon growth termination. These findings rule out the vapor–liquid–solid mechanism. Instead, driven by a strong lattice mismatch nanocolumnar nucleation occurs spontaneously by Volmer–Weber growth mechanism, whereas nitrogen excess prevents the nucleation sites coalescence. Further nanocolumnar growth proceeds by direct Ga incorporation on the nanocolumns top and by Ga diffusion along the nanocolumns sidewalls up to their apex. Related to this diffusion mechanism, we found that Ga droplets, when used, may act as reservoirs to feed Ga atoms to the neighboring nanocolumns. Nanocolumns preserve a constant diameter if growth conditions are not modified because of a strong metal ad-atom diffusion length along their sidewalls. The effect of using AlN buffer layers on the nanocolumnar growth and morphology is also addressed.

More information

Item ID: 2707
DC Identifier: http://oa.upm.es/2707/
OAI Identifier: oai:oa.upm.es:2707
DOI: 10.1016/j.jcrysgro.2008.05.057
Official URL: http://www.elsevier.com/wps/find/journaldescription.cws_home/505670/description#description
Deposited by: Memoria Investigacion
Deposited on: 12 Apr 2010 12:09
Last Modified: 20 Apr 2016 12:23
  • Logo InvestigaM (UPM)
  • Logo GEOUP4
  • Logo Open Access
  • Open Access
  • Logo Sherpa/Romeo
    Check whether the anglo-saxon journal in which you have published an article allows you to also publish it under open access.
  • Logo Dulcinea
    Check whether the spanish journal in which you have published an article allows you to also publish it under open access.
  • Logo de Recolecta
  • Logo del Observatorio I+D+i UPM
  • Logo de OpenCourseWare UPM