Abstract
We investigate the parameters used in the MOVPE growth of high‐N‐content In~x~ Ga~1–x~ As~1–y~ N~y~ films on GaAs and their structural and optical properties. The N incorporation control was found to mainly depend on the 1,1‐dimethylhydrazine (DMHy) molar flow rate and the growth temperature. With increasing the DMHy molar flow rate, the high‐resolution X‐ray diffraction measurements exhibited a clear diffraction peak shift, representing the increase in N incorporation. On the other hand, the N content was increased from y ∼ 0.5% to 3.6% with decreasing the growth temperature from 650 °C down to 500 °C. The red‐shift in both the photoluminescence (PL) peak and the photoreflactance (PR) signal (E ~0~ transition) with increasing N content was clearly observed. Finally, the lattice‐matched In~0.06~Ga~0.94~As~0.979~N~0.021~/GaAs film corresponding to the room‐temperature E ~0~ transition energy of 1.11 eV was achieved. It is noticeable that the structural and optical properties of the InGaAsN films grown using TBAs strongly depends on the N content, as in the case of corresponding films grown using AsH~3~. Besides, the PR spectral feature demonstrated the growth of the InGaAsN film whose bandgap is lower than 1.0 eV by using TBAs in place of AsH~3~. The present results show that the DMHy flow rate and the growth temperature play a critical role in the growth of high‐quality and single‐phase dilute‐nitride‐arsenide alloy semiconductors. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)