NSF Award
9901879
This Small Business Innovation Research Phase II Project will demonstrate unique capabilities at Xidex's Six Degree-of-Freedom Atomic Force microscope (6-DOF AFM) technology for use as a critical dimension (CD) metrology tool by semiconductor industry. Our CD-AFM design accommodates tilting of the AFM cantilever through large anqular ranges, thereby enabling the probe tip to access undercuts and re-entrant features. Our sensing system tracks the AFM cantilever in up to 6 degrees-of-freedom. The CD-AFM also allows operating the cantilever and tip in the X, Y, and Z directions, enabling is to determine 3-D surface slopes. This enables a scanning strategy where the raster step in Y can be altered for faster AFM imaging and better inspection of profiles in Y. Another advantage is elimination of cosine errors due to cantilever bending and tilt, vertical tip-sample alignment, and X and Y orthogonality error. The semiconductor industry recognizes that a viable alternative to CD-scanning electronic microscope (CD-SEM) technology will be required within the next few year!!. The shortcomings of CD-SEMs present an opportunity to develop a new AFM-based CD metrology tool to ultimately replace the CD-SEM and meet urgent needs of the National Technology Roadmap for production quality control at sub-180 nm feature sizes.<br/> Commercial applications include (a) critical dimension (CD) metrology tools for inline production quality control in semiconductor fabrication facilities and (b) tools for calibration of CD scanning electron microscopes (SEMs).
