Investigations of (GaIn)(NAs) bulk layers and (GaIn)(NAs)/GaAs multiple quantum well structures grown using tertiarybutylarsine (TBAs) and 1,1-dimethylhydrazine (UDMHy)

Abstract

The optimization of the metalorganic vapour phase epitaxial (MOVPE) growth of lattice-matched (GaIn)(NAs)/GaAs multiple quantum well (MQW) structures grown by using triethylgallium (TEGa) and trimethylindium (TMIn) in combination with tertiarybutyl arsine (TBAs) and 1,1-dimethylhydrazine (UDMHy) is investigated in detail by means of high resolution X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM) as well as photoluminescence (PL) measurements. The temperature range for the realization of high structural layer quality is established from about 500 to 525°C. MQWH with extremely narrow XRD linewidths of 21″ (FWHM) are achieved. The N-incorporation behaviour as a function of TBAs partial pressure, As/N-partial pressure ratio and of the growth rate is clarified in detail. The N-incorporation is reduced with increasing In-content in the (GaIn)(NAs) layer. Excellent surface morphologies indicatetd by smooth terraces with monolayer height steps are achieved for N-concentrations up to 4.5%. Above this critical value a deterioriation in structural quality is observed. The band gap reduction with increasing N-incorporation is established from PL studies at room temperature. The optical characteristics as a function of N-concentration and growth conditions are discussed briefly. PL emission of as-grown samples with wavelengths up to 1.55 μm at room temperature is achieved.