Approach to the analysis of gate oxide shorts in CMOS digital circuits

Abstract

Although many integrated circuit processing or in-field defects change the functional behaviour of the circuit and may be detected by classical testing techniques, small spot and break defects in the active area of the transistors may just cause electrical parameter changes. In our work, experimental results are presented in order to characterize the behaviour of a class of such faulty devices. A fault model for gate oxide shorts is presented and used to analyse the conditions under which a typical CMOS inverter becomes functionally faulty. Static current inspection testing technique is considered for this kind of fault, proposing a static current circuit checker.