Si impurity concentration in nominally undoped Al0.7Ga0.3N grown in a planetary MOVPE reactor

J. Jeschke, A. Knauer, M. Weyers

Published in:

J. Cryst. Growth, vol. 483, pp. 297-300 (2018).

Copyright © 2018 Elsevier B.V. All rights reserved. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the Elsevier B.V.


The unintentional silicon incorporation during the metalorganic vapor phase epitaxy (MOVPE) of nominally undoped Al0.7Ga0.3N in a Planetary Reactor under various growth conditions was investigated. Dependent on growth temperature, pressure and V/III ratio, Si concentrations of below 1 × 1016 up to 4 × 1017 cm-3 were measured. Potential Si sources are discussed and, by comparing samples grown in a SiC coated reactor setup and in a TaC coated setup, the SiC coatings in the reactor are identified as the most likely source for the unintentional Si doping at elevated temperatures above 1080 °C. Under identical growth conditions the background Si concentration can be reduced by up to an order of magnitude when using TaC coatings.

Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik, Gustav-Kirchhoff-Str. 4, 12489 Berlin, Germany


A1. Impurities, A1. Desorption, A3. Metal organic chemical vapor deposition, B1. Nitrides.