MOVPE-growth and characterization of metastable (GaIn)(NAs)/GaAs heterostructures for 1.3 μm lasers

In this work we present a detailed study on the determination of N and In content in (Ga(1-x)Inx)(NyAs(1-y)) material system and discuss the incorporation behaviour and the effect of alloy composition on device performance. (GaIn)(NAs)/GaAs heterostructures are grown on GaAs substrates by metalorganic vapour phase epitaxy (MOVPE). All layers are observed to be pseudomorphically strained as derived from comparison of symmetric and asymmetric high resolution x-ray diffractometry HRXRD reflexes. At first a series of about 60 nm thick GaNyAs(1-y) (0< y(N) <0.06) layers are gown. The nitrogen content was measured with SIMS and correlated with the strain results measured by HRXRD. This correlation is found to be consistent with Vegard's law. We have chosen the growth parameters of the GaNAs sample with the highest nitrogen content of y(N) =0.055 and investigated the incorporation of indium. It is observed that for increasing indium content the nitrogen incorporation decreases to y(N)=0.014 for x(In)=0.16. (GaIn)(NAs)/GaAs double quantum well (DQW) structures are grown to study the bandgap variation for indium amounts higher than 0.2. PL results show that only for high indium content superior PL-intensities can be observed. 3QW (GaIn)(NAs) laser structures exhibit threshold current densities of 0.67 kA/cm2 per quantum well at a wavelength of 1305nm.