Application of the Low-Loss Scanning Electron Microscope Image to Integrated Circuit Technology Part 1-Applications to Accurate Dimension Measurements
Michael T. Postek, Andras Vladar, O C. Wells, J R. Lowney
Scanning electron microscopes are the most extensively used tools for dimensional metrology and defect inspection for integrated circuit technologies with 180 nm and smaller features. Currently almost all SEMs are designed to collect as many electron secondary and backscattered electrons as possible. These signals are mainly secondary electrons (SEl,SE2 and SE3) detected with various detection schemes. To facilitate the electron collection very strong electric and magnetic fields are applied not just in the path of the primary electron beam, but to the emerging electrons as well. These new systems provide strong signals thus better signal-to-noise ratio and thus result in higher throughput than older ones. On the other hand, the use of secondary electrons means that measurement results are much more prone to the detrimental effects of electron beam interactions, sample charging and sample contamination than measurements with higher energy backscattered electrons. The use of backscattered electrons, especially low-loss electrons (LLE) can provide better surface sensitivity, edge accuracy and repeatability possibly at the expense of measurement speed.
backscattered electrons, detector, electron microscopes, linewidth, low loss electrons, secondary electrons
, Vladar, A.
, Wells, O.
and Lowney, J.
Application of the Low-Loss Scanning Electron Microscope Image to Integrated Circuit Technology Part 1-Applications to Accurate Dimension Measurements, Scanning
(Accessed November 30, 2023)