Structural, Optical and Morphological Properties of InxGa1-xAs Layers Obtained by RF Magnetron Sputtering

Indium gallium arsenide layers (InxGa1-xAs) were prepared on Silicon (100) and glass substrates in an argon atmosphere by R.F. magnetron sputtering. The growth temperature was 580 °C and high purity targets of gallium arsenide and indium were used. The effects due to the RF power for the In sputtering and the substrate type on the deposited films were studied by X-ray diffraction and Raman microscopy. These studies revealed the formation of InxGa1-xAs with the zinc-blende phase. The results also show that at low In sputtering RF power, there is a preferential growth along of (111) direction. Morphology and thickness of the layers were studied by scanning electron microscopy (SEM) and atomic force microscopy (AFM), revealing a variation of particle size and roughness. Energy dispersive spectroscopy (EDS) allowed us to determine the atomic percentages of In, Ga, and As. These results are in agreement with Raman measurements, where GaAs-like and InAs-like LO and TO vibrational modes were observed with a shift attributed to the indium concentrations in the InxGa1-xAs layers. By secondary ion mass spectroscopy (SIMS), the interface quality was studied. We conclude that at low In sputtering RF power InxGa1-xAs layers highly oriented along the (111) plane are obtained.