COOLING AS A POSSIBLE WAY TO EXTEND THE USABILITY OF I-DDQ TESTING

A reduction of the V-DD voltage, and thus the threshold voltage, in su bmicrometre CMOS circuits, results in an increase in the subthreshold current of the transistors and, consequently, in an increase in the ov erall quiescent current. This effect prohibits the use of I-DDQ testin g. Based on experimental investigation into the subthreshold character istics of deep submicrometre transistors, the authors propose a coolin g of the circuit under test as a method to reduce these difficulties.