Incorporation Behaviors of In and Ga in the Two-Heater MOVPE Growth of InGaN Films

Abstract

Incorporation behaviors of In and Ga of InGaN films grown by the two-heater metal-organic vapor-phase epitaxial horizontal reactor is investigated by varying growth parameters, such as the substrate temperature, ceiling temperature and reactor pressure. Two In loss mechanisms are observed by the analysis of the concentration and temperature profiles in the deposition zone. The gas-phase parasitic-loss mechanism (activation energy similar to 34.2 +/- 0.1 kcal/mol) is significant in the ceiling temperature T-ceil >= 800 degrees C and at substrate temperature (T-sub) of 600 degrees C. The decomposition-loss mechanism, which arises from In desorption on the growing surface, is significant in T-sub > 625 degrees C region. The desorption activation energy obtained is 28.0 +/- 0.1 kcal/mol, which is close to that of InN (25-26 kcal/mol). This suggests the In decomposition-loss mechanism in InGaN growth does not differ substantially from that in binary InN growth. On the other hand, the gas-phase parasitic-loss mechanism of Ga is negligible in the growth condition that we have explored. Exception is found for reactor pressure at T-ceil = 950 degrees C, where both factors advantageous and disadvantageous to Ga incorporation are unambiguously observed. We have proposed explanation for the above observation. (C) The Author(s) 2016. Published by ECS. All rights reserved.