GOALI: 2D High Resolution Dopant Profiling of Integrated Circuits Using Tapping Mode Atomic Force Microscopy

University Of South Florida, Tampa FL

Investigators

Abstract

0010059 Schlaf The proposed three-year research collaboration between Lucent Technologies and the PI focuses on the further development of a recently demonstrated new technique for laterally resolved 2D dopant profiling. This new technique uses standard tapping mode atomic force microscopy (TMAFM) with an applied direct current (DC) bias between cantilever and sample. Using the TMAFM phase signal, bias induced dopant density related variations in Coulomb forces are detected, yielding a dopant density map of the investigated surface. Since TMAFM is used to scan the surface, only very weak mechanical interaction with the surface occurs resulting in a potentially more stable operation than in to date used methods such as scanning capacitance microscopy (SCM) or nano-spreading resistance profiling (nano-SRP) where the probe presses down on the investigated surface during the measurement resulting in short probe life. While offering the benefits of reproducibility and long probe life, the spatial and doping density resolution limits of the TMAFM method are potentially similar to the existing methods. In this context the proposed program aims at the further exploration of the basic physical mechanisms of the method, finding and optimizing its maximum lateral and dopant density resolutions, calibrating it using industry standards and testing its application to "real life" industrial state-of-the-art integrated circuit samples. In summary, these efforts focus on developing the PI's method into a cutting edge metrology tool for integrated circuit research, development and production.