Recent developments of the RBS technique for the analysis of semiconductor nanostructures

It is well-known that in the case of high lattice mismatch the growth of semiconductor structures proceeds via island formation. The growth and characterization of the so obtained nanostructures has attracted increasing interest in the last few years due to their fascinating potential applications in integrated microelectronics. Apart from optical and electrical characterization, the structural analysis of these structures is usually performed by Scanning Electron Microscopy, Transmission Electron Microscopy or Atomic Force Microscopy: However, none of these techniques is suitable to exactly measure the total amount of deposited materials which is, together with the statistical distribution of the dimensions of the nanostructures, the most important information to be obtained. We have developed a new experimental set up for RES analysis which, in connection with a computer simulation code, improves the thickness resolution of the technique of nearly one order of magnitude. With this experimental arrangement InAs/GaAs, InP/GaAs and InGaAs/GaAs nanostructures, nominally few monolayers (ML) thick can be analyzed by obtaining the total amount of deposited material, the fraction of the surface covered by the nanostructures and their maximum thickness.