The use of the Fresnel Method for the measurement of the compositional profile of the interfaces of isolated sub-unit-cell-thick layers of Si in Ge

摘要

The Fresnel Method is used here to determine the compositional abruptness of the interfaces in a multilayer which was grown to have, within a period of the structure, a two monolayer thick Si layer and a much thicker Ge layer. The method has to be applied in different ways for the compositional profiling of fine period layer structures and isolated layers. Data obtained for short wavelength multilayers has indicated that such interfaces can be very sharp and here we examine the potentially simpler application of the method which is possible for well separated layers and discuss the implications of the results in relation both to the accuracy of the method and to the form which the interfaces take.