The state of VLSI testing

The phenomenal development in electronic systems has, in large part, the advances in Very Large Scale of Integration (VLSI) semiconductor technologies to thank. Performance, area, power and testing are some of the most important improvements. With the reduction in device sizes, it is becoming possible to fit increasingly larger number of transistors onto a single chip. However, as chip density increases, the probability of defects occurring in a chip increases as well. Thus, the quality, reliability and cost of the product are directly related to the intensity/level of testing of the product. As a result, gradually, Integrated Circuits (ICs) testing has shifted from the final fabricated ICs to the design stage. In this context, many Design For Testability (DFT) techniques have been developed to ease the testing process.