Vision and scanning probes inspect photomask defects: To check critical dimensions., advanced metrology systems combine visible-light microscopy with stylus nanoprofilometry

摘要

As digital-electronics clock speeds advance past 1 or 2 GHz, semiconductor manufacturers have to fabricate chips whose critical dimensions (CDs) are much smaller than a wavelength of light. The active elements in a digital IC are field-effect switching transistors, and the speed at which they can switch goes up as the gate width goes down. The minimum manufacturable gate width thus determines the maximum clock speed. Chipmakers look to semiconductor-manufacturing equipment vendors such as FEI Company to provide tools capable of reliably fabricating these structures.