New Technique for the Determination of Atomic Configuration at Semiconductor/Semiconductor Interfaces

In this paper we show that there is a fundamental strategic difficulty with this approach. As there is no structural change on crossing the interface, the question of the atomic configuration at a SC/SC interface is not structural but chemical in nature. Instead of determining where the atoms sit, one must decide which atom sits where. We describe a new technique, based on HRTEM, which is capable of simultaneously providing structural and chemical information on an atomic scale. We apply this method to the InGaAs/InP interface to show that an interface revealed by conventional lattice imaging on an atomic scale. Our imaging method is not only able to reveal interfacial steps whose extent in the direction of the electron beam is much smaller than the sample thickness, but can in principle determine the composition of a given atomic column at a SD/SC interface.