Evaluation of the accuracy and precision of STEM and EDS metrology on horizontal GAA nanowire devices

The scaling of device dimensions has resulted in a need for high resolution metrology techniques capable of measuring small CDs with a high degree of precision and accuracy. Scanning transmission electron microscopy (STEM) has previously been demonstrated to be a metrology technique capable of measuring small CDs and gathering large volumes of accurate and precise metrology data. In addition, energy dispersive X-ray spectroscopy (EDS) metrology has also been demonstrated to be a powerful technique enabling the detection and measurement of low contrast layers, specifically for 3D NAND devices. Benchmarking EDS metrology against STEM metrology in terms of precision and accuracy is important to further investigate the capabilities of EDS metrology for the semiconductor industry. This study was performed using the latest technology in EDS detectors, along with automated acquisition and metrology software to generate large metrology data sets on horizontal nanowire structures. In this paper, we present data to support our finding that EDS metrology is well-matched with STEM metrology in terms of both precision and accuracy. In addition, we discuss the capability of EDS and STEM metrology to detect subtle process variations in next-generation logic devices.