Stylus NanoProfilometry: A New Approach to CD Metrology

The Stylus NanoProfilometer is a tool that provides nondestructive profilometry of structures encountered in semiconductor manufacture. Results from scans of photoresist and photomasks are shown. The challenge in applying scanning probe microscopy and stylus profilometry to advanced CD-measurement wafer processing applications lies in control. To obtain an accurate profile of a feature on the nano-scale, the sample surface cannot be altered by the measurement and the probe tip or stylus shape must be known and cannot change during the measurement. Our joint engineering projects, in which we studied the sources of error in existing techniques and how to control them, has yielded a new moniker for metrology - Stylus NanoProfilometry (SNP).