Electrical failure analysis in high density DRAMs

As density and complexity increase, the search for new test and analysis techniques can impact the role of failure analysis especially in the correct identification of failure mechanisms for root cause fixes to ensure timely introduction of a new product in a relatively competitive market. Design for Testability (DFT) offers some flexibility in trying to meet the demands made on the production test and on the defect analyses by reducing the time per test and in helping to carry out some specific type of tests. This paper presents test results of investigations carried out with the help of some DFT tests on the 1-Megabit, 4-Megabit and 16-Megabit Dynamic Random Access Memories (DRAMs) to detect the cause of an electrical fault in more detail. Several case examples depicting this work are presented.<>