Analysis of MBE Brown Al(x)Ga(1-x)As - GaAs Heteroepitaxial Layers by Rutherford.

The Rutherford Backscattering(RBS) technique has been optimized for the measurement of thin (> 85angstroms) alternating layers of Al(x)Ga(1-x) As and GaAs, which are at the limit of resolution of standard RBS measurements. RBS analysis of these structures provides both layer thicknesses and Al content. This information is useful for device processing since the layer thicknesses impact the FET threshold voltage and the Al content is important for proper selective chemical etching. Experimental conditions for the beam energy, detection angle, and sample rotation have been determined which allow measurement of the layer thicknesses to a precision of +-20-30angstroms (for layers > 85angstroms) and of the Al content, x, to a precision of +-.02.