Automation to Enable Energy Dispersive X-ray Spectroscopy for High Throughput Failure Analysis and Metrology

Abstract Automated S/TEM (auto-S/TEM) and by extension automated energy dispersive x-ray spectroscopy (auto-EDS) enable the collection of large volumes of data that historically was not feasible on a sustained basis using manual S/TEM operation. Automation removes variabilities attributed to operator training and bias while enabling repeatable, precise, and consistent data. This paper examines general considerations for high volume and auto-EDS metrology. Maps are evaluated relative to analysis time and the requisite signal-to-noise (SNR) necessary for adequate measurement precision. Auto-EDS parameters (dwell time and mapping time) were investigated to maximize EDS net counts and SNR for throughput. A methodology was presented to monitor the SNR ratio of critical dimensions which can be extended to further understand the minimum value needed to maintain an acceptable measurement precision. It is important to further study other means of increasing the SNR, such as beam current, accelerating voltage, and larger solid-angle detectors.