Scanning diffraction microscopy from InGaN pseudo-substrates

The objective of this study is to obtain a microscopic mapping of the full tensors of strain and lattice orientation of an In-enriched InyGa1-yN layer on porous InxGa1-xN/GaN/sapphire, to produce pseudo-substrates for InGaN red micro-LEDs. As the size of the micro-LEDs is typically about 10 µm, an excellent in-plane homogeneity of the pseudo-substrate is needed. Therefore, we are applying for the ability to measure Scanning X-ray Diffaction Microscopy (SXDM) maps covering several tens of µm² with a 50 nm accuracy. The crucial point here is to determine if the porosification of the InxGa1-xN underlayer leads to inhomogeneity of the strain or the lattice orientation of the In-enriched InyGa1-yN upper layer.