Introduction to reliability
Reliability is an important factor in any semiconductor or packaging process technology development. As a consequence of the strong reduction in geometries, the internal electrical fields and current densities are continuously increasing, leading to a number of reliability problems, such as time-dependent dielectric breakdown, hot carrier degradation, electro-migration and stress induced voiding, etc. Also the devices and circuits are becoming more vulnerable to effects such as electrostatic discharge (ESD), which strongly limits not only the reliability but also the yield of the circuits. New materials, such as high-k gate dielectrics and Cu and low-k materials, and new device architectures such as multiple gate FETs as well as new technologies like micro-electromechanical systems (MEMS) and packaging technologies are introduced. For these new materials, devices and technologies the failure mechanisms are still not well understood and their speed of introduction exceeds the capability to explore their reliability.
IMEC has built-up a strong expertise in the field of reliability. These reliability activities are carried out in the framework of the respective technology development programs, but the reliability competences are brought together in an expertise center called Reliability@IMEC. In this expertise center, research is carried out on basic failure mechanisms, reliability of specific technologies and reliability tools and methods.
This part of the scientific report, brings together the highlight results on gate-stack reliability in both SiON and high-k/metal-gate stacks, on electromigration and stress induced voiding in Cu metallization, on dielectric reliability problems in low-k dielectrics, on ESD protection issues in high-k/metal-gate and FinFET devices and for RF-CMOS circuit applications, as well as results on MEMS reliability problems and reliability activities for advanced packaging technologies.
Also, part of the reliability work is done at IMEC's associated laboratory IMOMEC (see section AC electromigration testing), (see section High sputter bias super secondary Cu grain growth initiation (in structures)), (see section High-temperature reliability issues of gate oxides), (see section Synthesis and characterization of submicron metal-oxide coatings).