Design for Reliability (DfR) - A key requirement for modern product design

Abstract:
Modern state of the art CMOS technologies show inevitable parameter degradation of their devices during use. Device degradation mechanism like NBTI or HCI became a limiting factor in scaling of modern CMOS technologies. The safety margin between real lifetime of MOSFETs and product lifetime requirements decreases at advanced technologies. The assignment of tasks to ensure the product lifetime has to be changed for the future. Up to now technology development and reliability group have the main responsibility to adjust the technology processes to assure the required lifetime. In future, achieving reliability targets can no longer be the task of these both groups only. It has to be a collective challenge for technology-, reliability- and circuit designer-experts. A close collaboration early in development of new technologies and circuit design in terms of reliability is needed to achieve reliable and competitive products. For this work designers have to be supported by smart software tools with built-in reliability know how. "Design for reliability (DfR)" will be one of the key requirements for modern product designs. This paper will give a brief introduction of the NBTI and HCI phenomenon. An overview will be given of the physical damage mechanism, of the operation conditions within circuits leading to stress and of the impact of the corresponding device parameter degradation on the function of the circuit. Based on this understanding the function of aging simulators will be explained and the typical flow of circuit simulation will be shown. Furthermore the difference between full custom and semi custom design and therefore the different required approaches will be discussed.