Automated Wafer Testing

A test system was installed at JUT that can automatically test every die on a wafer without any operator interruption. The system integrates a Rucker & Kolls 681A wafer probe station, an HP4145 parameter analyzer, an HP Apollo work station, and a Keithley switch matrix. IC-CAP software was used for system control and data extraction. The system was designed to be flexible so additional tests can he added. Any process and any test that an HP4145 can complete manually can be tested using the automated system. Only a few variables regarding die size, device location, data extraction methods, and HP4145 test parameters, need to be changed. For demonstration of the system, the RIT PMOS process was used, and threshold voltage was measured, extracted and stored