| Popis: |
A fundamental requirement in critical dimension measurement is determination of the edge positions. Edge position measurement can be degraded by many sources of error, the probe‐sample interaction usually being the most important of them. In most cases a sharp conical probe is adequate to locate the top of an edge, and it can scan the entire edge if the walls are not too steep. We discuss aspects of the measurement that affect the uncertainty, such as tip radius, instrument drift, and surface roughness. Measurements with a conical probe of two samples are included. The first is very thin chrome on a quartz substrate, and the second sample is photoresist on a Si wafer. |
