Electron beam metrology for advanced technology nodes

Abstract

The critical dimension scanning electron microscope (CD-SEM) is one of the main tools used to estimate critical dimension (CD) in semiconductor manufacturing nowadays, but, as all metrology tools, it will face considerable challenges to keep up with the requirements of the future technology nodes. The root causes of these challenges are not uniquely related to the shrinking CD values, as one might expect, but to the increase in complexity of the devices in of morphology and chemical composition as well. In fact, complicated three-dimensional device architectures, high aspect ratio features, and wide variety of materials are some of the unavoidable characteristics of the future metrology nodes. In this paper, we report on the development of advanced CD-SEM metrology at imec on a variety of device platforms and processes, for both logics and memories. The large variety of results reported here a clear indication of the on-going creative effort needed to ensure that the critical potential of CD-SEM metrology tools is fully enabled for the 5 nm node and beyond.