A Correlative Analysis Flow for Electrical and Structural Characterization of IGZO Transistors

We report on a custom sample preparation flow for correlative metrology. This is applied here to the electrical, structural, and compositional analysis of Indium-Gallium-Zinc- Oxide thin film transistors (IGZO TFTs). Here, conductive atomic force microscopy (C-AFM) and transmission electron microscopy (TEM) are repeatedly combined on the same structure to maximize the amount of site-specific device information. First, the analysis-flow is described in detail, describing the specimen preparation that enables both electron transparency and mechanical stability. Second, the direct correlation of structural and electrical information is provided with emphasis on the channel and contacts regions, where additional insights are provided by combining multiple measurement techniques. This opens new possibilities in the evaluation of process development for complex samples, well beyond what is reported here.