H- and D-related mid-infrared absorption bands in Ga 1-y In y As 1-x N x epitaxial layers

Epitaxially grown ternary and quaternary layers of GaAs based dilute nitrides have been exposed to H+ and D+ ion bombardment to investigate the interaction between hydrogen (deuterium) and nitrogen. Low-temperature Fourier transform infrared absorption measurements reveal the formation of N–H (N–D) complexes by the appearance of high-frequency absorption bands in the mid-infrared due to vibrational modes of H(D). In thin layers, the transformation of isolated substi- tutional nitrogen, NAs, into complexes involving H (D) is complete, in thick (500–1000 nm) layers only partial. Analyses of the band intensities dependent on variations of the sample structure and parameters during ion irradiation challenge the model of a unique defect associated with the observed vibrational modes. A new model is proposed based on two different N–H (N–D) centers, each involving one H (D) atom. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)