Measurements of Ga_1-xAl_xAs Layers on GaAs with EDS

Abstract

GaAlAs is a basic material in semiconductor technology and thus of great interest for industrial research. Several Ga_1-xAl_xAs bulk samples of predefined composition as well as layered samples of well defined thicknesses and composition were investigated. The experimental data are analyzed with a computer program, which has been developed at the Institute for Applied and Technical Physics at the Technical University of Vienna. Furthermore, analysis of the bulk samples using the program PAP of Pouchou and Pichoir is carried out. An excellent agreement of both correction procedures with the defined composition values is obtained. The determined layer thicknesses also correspond well with the defined data.

For our calculations the total K-peak of aluminum and the total L-peak of gallium and arsenic were measured. Reducing the L-intensities by the already published relative intensity factor for La radiation leads to less correspondence of the calculated k-ratios compared to the measured values. By additionally regarding the emerging Lß intensities with partly much higher mass absorption coefficients than the corresponding values for Lα radiation a dramatic improvement is achieved.

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