Analysis of the two-dimensional-dopant profile in a 90 nm complementary metal–oxide–semiconductor technology using scanning spreading resistance microscopy

In this study we demonstrate the capabilities of scanning spreading resistance microscopy (SSRM), which is an atomic force microscope based technique, for two-dimensional (2D) carrier profiling with nanometer spatial resolution, high quantification accuracy, and high concentration sensitivity. As a test vehicle we discuss the application of SSRM on devices obtained from a 90 nm node complementary metal–oxide–semiconductor technology. Transistors processed in this technology, and with poly-gate lengths down to 70 nm have been analyzed using SSRM. Dedicated quantification software has been used to calculate carrier concentration profiles. The source/drain implants and the halo- and threshold voltage adjustment implants have been analyzed for different gate sizes in order to understand their impact on the 2D channel carrier profile. The SSRM results have been compared to the results of calibrated process simulators.