Three-Dimensional Structure Analysis of Metal–Oxide–Insulator Field Effect Transistors with Different Electrical Properties by Scanning Transmission Electron Microscopy

To clarify the origin of on-state drain current (ION) variability in metal–oxide–semiconductor field-effect transistors (MOSFETs), we applied three-dimensional scanning transmission electron microscopy (3D STEM) observation to two transistors that had different ION values but the same threshold voltage (VT). The results clearly showed a difference in the distance between the gate and source/drain silicide, suggesting that the ION difference between two transistors can be explained by the difference in the source/drain extension resistance. We showed that it is possible to discuss the 3D device structures in relation to their electrical characteristics.