Strain engineering of AlGaN-GaN HFETs grown on 3 inch 4H-SiC

Published in:
phys. stat. sol. (c), vol. 6, no. S2, pp. S1065-S1068 (2009).
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Abstract:
In this work strain evolution during MOVPE of AlGaN/GaN HFET structures on 3 inch SiC substrates is investigated in-situ and related to properties of the initial AlN wetting layer. It is shown that the density of pits on the AlN surface depending on growth conditions influences GaN nucleation and consequential grain coalescence and stress incorporation. Optimization of the strain and material quality of the GaN layer is demonstrated without degrading the semiinsulating properties of the HFET buffer.

PACS:
61.72.Hh, 68.35.Gy, 81.05.Ea, 81.15.Kk, 81.40.Jj, 85.30.Tv

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