Overview

No silicon integrated circuit (IC) manufacturing process is perfect. Therefore, IC testing is used to screen imperfect devices before shipping them to customers. Chips containing manufacturing defects are potentially malfunctioning chips that may cause system crashes and lead to financial deficit, environmental disaster, and/or jeopardize human life. Moreover, if manufacturing defects are not detected early, the cost of repair is increased by an order of magnitude at each step after the chip fabrication line. It comes naturally that chip testing is an important factor of the business in computer and communications industries, since customers demand reliable products at a reasonable cost and manufacturers, in order to stay competitive in business, must find the means to provide the best products at the lowest cost.

IC testing is done in several phases of chip realization process. When a new chip is first designed and fabricated, first silicon debug and validation of early prototypes of the chip in the design laboratory should verify that the design is correct and meets all specifications. During this phase, functional tests are applied, comprehensive AC and DC measurements are made, design errors are corrected, final specifications are set (e.g. the limits of chip operating values), as well as the manufacturing process and corresponding yield are improved. Besides, during this phase, test development for manufacturing testing is verified and improved,...