Electrical characterization of semiconductor materials and devices using scanning probe microscopy

Several scanning probe microscopy (SPM) modes exist for the electrical characterization of semiconductor materials and devices with nm-scale resolution. The most important electrical SPM modes are: scanning capacitance microscopy (SCM), scanning spreading resistance microscopy (SSRM), and tunneling-AFM (TUNA). SCM and SSRM are primarily used for 2-D carrier profiling and resistivity mapping on cross-sectioned devices. The spatial resolution is on the order of 20 nm, while the dynamic range goes from 10(15) to 10(20) atoms/cm(3). Imaging examples are shown for sub-quarter micron MOSFETs, ferro-electric material, and compound semiconductor structures. The TUNA method allows one to perform thickness mapping and defect imaging of thin dielectric films using a tunneling current flowing between the SPM tip and the sample. Spatial resolution is on the nm-scale: while the current range is from 50 fA to 120 pA. Examples are shown of gate oxide breakdown and defect localization in thin gate oxides. (C) 2001 Elsevier Science Ltd. All rights reserved.