Reliability of a semiconductor device is the ability of the device to perform its intended function during the life of the device in the field.
There are multiple considerations that need to be accounted for when developing reliable semiconductor devices:
- Semiconductor devices are very sensitive to impurities and particles. Therefore, to manufacture these devices it is necessary to manage many processes while accurately controlling the level of impurities and particles. The finished product quality depends upon the many layered relationship of each interacting substance in the semiconductor, including metallization, chip material (list of semiconductor materials) and package.
- The problems of micro-processes, and thin films and must be fully understood as they apply to metallization and wire bonding. It is also necessary to analyze surface phenomena from the aspect of thin films.
- Due to the rapid advances in technology, many new devices are developed using new materials and processes, and design calendar time is limited due to non-recurring engineering constraints, plus time to market concerns. Consequently, it is not possible to base new designs on the reliability of existing devices.
- To achieve economy of scale, semiconductor products are manufactured in high volume. Furthermore, 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, environmental, and cooling conditions. Stress factors affecting device reliability include gas, dust, contamination, voltage, current density, temperature, humidity, mechanical stress, vibration, shock, radiation, pressure, and intensity of magnetic and electrical fields.
Design factors affecting semiconductor reliability include: voltage, power, and current derating; metastability; logic timing margins (logic simulation); timing analysis; temperature derating; and process control.