Title

Enhanced control over selective-area intermixing of In0.15Ga0.85As/GaAs quantum dots through post-growth exposure to radio-frequency plasma

Authors

Authors

N. Bickel;P. LikamWa

Comments

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Abbreviated Journal Title

Thin Solid Films

Keywords

Quantum dots; Post-growth intermixing; Plasma treatment; Bandgap; engineering; Interdiffusion; Semiconductor epitaxial layer; Optical; properties; Impurity free vacancy disordering; FREE VACANCY DIFFUSION; WELL WAVE-GUIDES; ION-IMPLANTATION; BANDGAP; SHIFTS; LASER-DIODES; CF4 PLASMA; INTERDIFFUSION; INP; SUPPRESSION; HYDROGEN; Materials Science, Multidisciplinary; Materials Science, Coatings &; Films; Physics, Applied; Physics, Condensed Matter

Abstract

Post-growth treatment with a low pressure, CF4-plasma is demonstrated to reliably inhibit the interdiffusion of In and Ga atoms in In0.15Ga0.85As/GaAs self-assembled quantum dot wafer structures subjected to rapid thermal annealing temperatures between 700 degrees C and 800 degrees C for a duration of 20 s. Comparative studies of the effects of rapid thermal annealing were made on plasma treated samples and samples that were capped with either 200 nm of plasma enhanced chemical vapor deposited SiO2 or 220 nm of thermally deposited TiO2 prior to plasma exposure, as well as to uncapped, untreated control samples. Room-temperature photoluminescence spectra were acquired using a Ti-Sapphire laser operating at 742 nm as the excitation source. A bandgap differential of 84 meV (94 nm) was measured across a wafer sample annealed at 775 degrees C, when contrasting sections that were uncapped and treated with the CF4-plasma versus sections that were annealed without any treatment to the surface. This was comparable to a sample that was capped with the TiO2 film, whichproduced a 73.5 meV (82 nm) variance from the raw, annealed-only sample. (C) 2010 Elsevier B.V. All rights reserved.

Journal Title

Thin Solid Films

Volume

519

Issue/Number

6

Publication Date

1-1-2011

Document Type

Article

Language

English

First Page

1955

Last Page

1959

WOS Identifier

WOS:000287339000032

ISSN

0040-6090

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