A primary goal of this project is to develop intrinsic calibration standards based on the crystalline lattice. The ultimate limit for nanoscale length metrology is the development of intrinsic calibration standards, where the reference dimensions are based on atom spacing within an ordered, crystalline lattice. Using techniques developed within this project, advanced step height, linewidth and pitch standards exhibiting picometer accuracy are being developed, using an ultra-high vacuum scanning tunneling microscope (UHV-STM). In addition, a project goal is to validate the use of atomic lattice spacing as a ruler through comparison with interferometric length measurements such as those performed in the Molecular Measuring Machine. The atom-based dimensional metrology project is leveraging this knowledge to develop the metrology science needed to enable parallel, high-throughput, atomically-precise manufacturing for NIST standards development and for industrial applications.
The atom-based dimensional metrology project is developing a new, comprehensive approach to dimensional metrology using the atom spacings of a crystal as the fundamental “ruler” or scale. Based on this metric, larger scale features will be etched into substrates to serve as critical dimension or pitch references for instruments having less-than-atomic resolution. Crystal-lattice dimensional parameters will be validated through interferometer measurements. This work will primarily be done by employing two complex multi-chamber vacuum STMs. The system contains ultra high vacuum (UHV) facility regularly capable of producing 1 x 10-8 Pa base pressures, along with vibration isolation that yields a sub-100 pm noise floor, and includes a unique field-ion/field-electron microscope (FIM), which is used to image scanned probe tips on the atomic scale and is being used to develop repeatable, robust methods for atomically sharp STM tip production. The project is developing improved nanofabrication methods using the STM to write atomic-scale features on the surface of hydrogen-passivated silicon substrates using scanning probe oxidation for accurate nano-standard development. Atom-based step height standards having picometer accuracy will also be developed, validated and characterized by an interferometer-instrumented atomic force microscope. The similar process can be applied to the device fabrication such as a single atomic transistor by laying a single phosphor atom in si substrate.
There are three major tasks in this project:
Lead Organizational Unit:pml
Physical Measurement Laboratory (PML)