Characterization of strained silicon quantum wells and Si1-xGex heterostructures using Auger electron spectroscopy and spreading resistance profiles of bevelled structures

Critical fabrication parameters of modulation-doped Si/ SiGe heterostructures may be extensively and quickly characterized using a combination of spreading resistance profile measurements and scanning Auger electron spectroscopy on bevelled heterostructures. We have used this combined approach, with relatively accessible characterization tools, to determine the thickness, composition and doping concentrations in the supply, spacer, well, buffer and graded layers of the heterostructures. Depth profiles of the active layers and virtual substrate can be assessed in a straightforward manner, allowing for optimization of processing parameters and of the overall device structure.