Reliability concerns the characteristic of a device to remain functional during a period of
time under established environmental conditions. Ultimately, every device will eventually
fail. The task of the reliability study is to provide technology to keep a device economically
viable despite failure. Reliability of semiconductors has its own particularities, which were
summarized in a 2010 report from the Reneseas Electronics Corporation of 2010 
Those five points emphasize the importance of a good design and process control to prevent
device failure. The mechanisms of failure must be understood during the development stage
of the product, otherwise it can be too late to repair it.
A device failure can have different reasons. It can arise from electrical effects (e.g.
negative-bias temperature instability), mechanical forces, material degradation,
environmental, and even a combination of several effects (e.g. electromigration). The
mechanical reliability of semiconductor devices are commonly associated with
fracture and fatigue prevention. The main goal of the mechanical study is to identify
situations, where a device structure could be damaged beyond repair. Therefore, in
addition to the stress-strain theory established in the last section, a method is needed
to determine when a deformation ceases to be elastic and becomes plastic and
- Semiconductor devices have a configuration, which is fundamentally
very sensitive to impurities and particles, and the stability status
of the surface state is extremely important. Consequently, to
manufacture these devices it is necessary to manage many processes
while completely controlling the level of impurities and particles.
Furthermore, the quality of the finished product depends upon
the complex relationship of each interacting substance in the
semiconductor, including chip material, metallization and package.
- The problems of thin films and micro-processes must be fully
understood as they apply to metallization and bonding. It is also
necessary to analyze surface phenomena from the aspect of thin films.
- Due to the rapid advances in technology, many new products are
developed using new processes and materials, and there is a high
demand for product development in a short time period. Consequently,
it is not possible to refer to the reliability achievements of existing
- In greed, semiconductor products are manufactured in high in volume.
In addition, repair of finished semiconductor products is impractical.
Therefore incorporation of reliability at the design stage and reduction
of variation in the production stage have become essential.
- Reliability of semiconductor devices may depend on assembly, use,
and environmental conditions. Stress factors effecting device reliability
include voltage, current density, temperature, humidity, gas, dust,
contamination, mechanical stress, vibration, shock, radiation, and
intensity of electrical and magnetic fields.