In-line electrical probe for CD metrology below 0.5 μm

As device linewidths shrink to 0.5 μm and below the ECD (Electrical Critical Dimension) measurement technique is the best choice for conducting substrates. In this size regime, ECD is poised to replace SEM (Scanning Electron Microscope) as the standard tool of the semiconductor industry, with a measurement capability significantly better than that of the CD SEM. Keithley Instruments has developed an advanced electrical prober for use at Motorola\´s MOS-12 facility. This tool provides in-line CD measurements in a completely automated, hands-off "load-and-go" mode that requires only wafer loading, measurement recipe loading, and a "run" command for processing. Its expected capability will permit measurement of lines thinner than 0.5 μm with a good accuracy, and with complete data transfer to the factory data collection and analysis system upon measurement completion. Results on the repeatability and reproducibility of fully automated measurements are presented, together with correlation to SEM measurements.