Detailed structural characterisation of semiconductors with X-ray scattering

The physical properties of devices critically depend on the structural parameters, from thickness and composition to aspects of the microstructure. The measurement of alloy composition and thickness in perfect semiconductors, for example, can be determined automatically using dynamical scattering theory. As the challenge to mix various materials with different lattice parameters appears evermore inviting the microstructure and state of strain become very important parameters. Also the X-ray scattering becomes more complex. This paper demonstrates the value of reciprocal space mapping and how information can be extracted directly, with examples of GaN device structures and InGaAs quantum dot structures. These reciprocal space maps have also been simulated using an extended dynamical model to accommodate mosaic regions and defects within samples. The potential of this approach is briefly discussed.