A reliable approach to prepare brittle semiconducting materials for cross-sectional transmission electron microscopy.

Here, we present a sample preparation approach that simplifies the thinning of very brittle wide bandgap semiconducting materials in cross-section geometry for (scanning) transmission electron microscopy. Using AlN thin films grown on sapphire and AlN substrates as case studies, we demonstrate that high-quality samples can be routinely prepared while greatly reducing the preparation time and consumables cost. The approach removes the sample preparation barrier to studying a wide variety of materials by electron microscopy.