Role of transmission electron microscopy in the semiconductor industry for process development and failure analysis

Abstract

Transmission electron microscope (TEM) based techniques offer superior spatial resolution and highly sensitive elemental analysis capabilities that can be exploited for metrology and materials characterization of sub-nanometer sized device features in advanced semiconductor technologies. TEM based techniques are suited for evaluating interfacial details, dimensions of device structures, and defects or flaws that arise during the fabrication process. In this work, TEM based techniques that are commonly used for physical characterization, compositional analysis, and failure analysis of semiconductor device structures are reviewed. Sample preparation methods, based on focused ion beam milling that is capable of site specific sample preparation, are also reviewed. The strength of these methods as well as problems, such as focused ion beam induced damage and gallium contamination, and methods to control them are described. Examples are presented from case studies that are required for process development, yield enhancement, and failure analysis of semiconductor manufacturing. Challenges faced due to introduction of alternative gate structures, nano-sized features, high-K gate dielectrics, and new materials needs in the integration of device structures are addressed.