Invited Paper SS+EM-WeA3
3D Atomic Scale Structure Analysis of Semiconductor Nanostructures by Atom Probe Tomography and Cross-Sectional STM

Wednesday, October 31, 2012, 2:40 pm, Room 22

Present day semiconductor science depends heavily on the construction of precise nanostructures in which atomic scale details are of key importance in the understanding and utilization of such nanostructured semiconductor materials. It is thus of key importance to have techniques that allow such details to be assessed by novel microscopy techniques that can obtain, preferable in 3D, atomic resolution. In this presentation I will present recent results that we have obtained by two exciting techniques that allow for an atomic scale resolution. We have used cross-sectional Scanning Tunneling Microscopy (X-STM) and Atom Probe Tomography (APT) on a range semiconductor nanostructures such as quantum dots and rings. The X-STM technique offers a superb 2D true atomic resolution in a single atomic plane intersecting the nanostructure. Atom Probe Tomography is a technique that has recently become available for the analysis of semiconductor nanostructures. Laser induced field emission is used to get a full atomically resolved 3D map of the composition of semiconductor nanostructure. In the presentation I will apply and compare these techniques on quantum dots and rings that have been obtained by various growth procedures such as the traditional Stransky-Krastonow process, droplet epitaxy or by applying Sb during the dot formation process.