Metrology for Conventional and Quantum Devices in the Few Nanometer to Single Atom Regime
There has been significant progress in the last decade to develop repeatable methods for the fabrication of devices with critical dimensions from the few nanometer regime down to devices that utilize individual atoms for their functionality. These devices include ultimately scaled single atom transistors and single or few atom structures used to isolate individual electrons for use as qubits in quantum computing. Critical device properties, such as tunnel coupling and tunnel rates, change significantly due to a single dimer row change in the tunnel gap (~0.5 nm). Likewise, a one dopant atom versus two dopant atom transistor has very different electronic properties. This presentation will discuss the metrology and materials problems encountered in making these kinds of devices. TEM, SIMS, and other conventional metrologies are pushed to their limits at these dimensions and need to be supplemented with novel methods that rely on the quantum mechanical properties fundamental to this length scale. Similar challenges exist in pushing cleanliness and defect metrology to the single atom scale, and understanding the effects of materials homogeneity on device performance.