Scanning spreading resistance microscopy of fully depleted silicon-on-insulator devices

Scanning spreading resistance microscopy (SSRM) is an electrical characterization tool used for the measurement of the 2D carrier distribution in semiconductor devices. In this technique an atomic force microscope is used to measure the local resistance of a semiconductor sample, which is later related to the doping concentration. SSRM was performed in fully depleted silicon-on-insulator (FD-SOI) devices and was able to satisfactorily resolve the different doping regions of the devices. In order to increase the spatial resolution the measurements were repeated on a new PMOS-SOI transistor with a gate length of 300 nm and with a bevel in the polishing step of similar to20degrees. The effective gate length of the device was measured and even the gate oxide, with a nominal thickness of only 3 nm, could be resolved. This brings SSRM closer to the metrology requirements of the International Technology Roadmap for Semiconductors (ITRS). (C) 2003 Elsevier Science B.V. All rights reserved.