Nanoscale Chemical-Mechanical Characterization of Nanoelectronic Low-k Dielectric/Cu Interconnects

摘要

Combined nanoscale chemical and mechanical property characterization has largely been limited by the inability to extend chemical structure identification techniques such as infrared (IR) absorption spectroscopy into the nanometer regime due to diffraction limitations. The recent development of atomic force microscope (AFM) based IR spectroscopy (AFM-IR) has now enabled infrared chemical spectroscopy with resolution well below the diffraction limit. However, the combination of AFM-IR with other AFM based techniques to achieve nanoscale chemical structure-mechanical property characterization has yet to be demonstrated. In this regard, we have combined AFM-IR chemical and contact resonance AFM (CR-AFM) mechanical measurements in the investigation of low dielectric constant (low-k) / Cu damascene structures fabricated using a 90 nm interconnect process technology. We show that the combined AFM-IR and CR-AFM results can be utilized to perform nanoscale chemical-mechanical characterization of both the nano-patterned metal and the low-k dielectric whose mechanical properties are sensitive to chemical modification by the interconnect fabrication process. (C) 2015 The Electrochemical Society. All rights reserved.