SBIR Phase I: New Flexible-Tip AFM Mode for High Aspect-Ratio Feature Metrology

This Small Business Innovation Research (SBIR) project will demonstrate the feasibility of a new AFM imaging mode that exploits lateral bending and lateral oscillation of flexible tips, including carbon nanotube tips, as an advantage rather than trying to deal with lateral tip flexure as a disadvantage. The flexible tip AFM mode will enable the semiconductor industry community to access and image both sidewalls and depths of high aspect features. Tips designed to implement the new imaging mode will enable customers to use carbon nanotubes to image high aspect ratio trenches, contact holes and vias without the sidewall sticking problem that occurs when carbon nanotube tips are used with existing AFMs. Both non contact and contact mode operation will be investigated as well as tip characterization, needed for metrology applications and vertical operation, needed to measure and image feature bottoms, tops and corners. The new AFM imaging mode leverages existing, patented carbon nanotube growth process which are now being used to fabricate carbon nanotubes directly on the apexes of AFM tips for use by semiconductor industry manufacturers.Commercially, introduction of a flexible tip scanning mode innovation has the potential to expand the usefulness of carbon nanotubes as AFM tips beyond the semiconductor industry. AFM users in biology, medicine, materials science, forensics and other fields have increasing needs to image three dimensional structures. The same flexible tip technology used to image challenging semiconductor features at the nm scale can also be used to image features of interest to this broader community of AFM users.