Search for content and authors

Modelling of indium rich clusters in MOCVD InGaN/GaN multilayers

Grzegorz Jurczak 2Grzegorz Maciejewski 2Slawomir Kret 1Paweł Dłużewski 2Pierre Ruterana 3

1. Polish Academy of Sciences, Institute of Physics, al. Lotników 32/46, Warszawa 02-668, Poland
2. Polish Academy of Sciences, Institute of Fundamental Technological Research (IPPT PAN), Świętokrzyska 21, Warszawa 00-049, Poland
3. Laboratoire CRISMAT - UMR 6508, ISMRA et Universite de Caen, 6 Boulevard de Marechal JUIN, Caen 14050, France


In this approach the study of a 1-5 nm diameter indium cluster in MOCVD InGaN/GaN quantum well is presented. The quantitative High Resolution Transmission Electron Microscopy (HRTEM) coupled with image simulation and Finite Element Method (FEM) thin foil relaxation modeling are used. Results obtained by means of those two technics are compared.
The measurement of tetragonal distortion from experimental images is the powerful tool for the determination of chemical composition in heterostructures. Transmission Electron Microscopy samples used in high resolution mode have 5-15 nm thick for 11-20 zone axis. So, the foil thickness is bigger that the size of studded nanocluster. For the correct interpretation of the measured lattice distortion on HRTEM images one needs to take into account the strain averaging across TEM sample and inhomogeneous relaxation of the sample. As a function of a chemical composition, size and position of In cluster relative to foil surface the 3D FEM modeling of such relaxation phenomena have been performed. Obtained 3D displacement distribution were used to simulate the HRTEM images. The results show that such modeling, which takes into account the atomic column bending, gives well matching of simulated images with the experimentally observed. Additionally the most probable size, position in quantum well and indium concentration are determined with small error bar.


Legal notice
  • Legal notice:

Related papers

Presentation: oral at E-MRS Fall Meeting 2003, Symposium B, by Grzegorz Jurczak
See On-line Journal of E-MRS Fall Meeting 2003

Submitted: 2003-05-27 18:01
Revised:   2009-06-08 12:55