Purging - A reliability assurance technique for new technology semiconductor devices

The use of new technology devices has the potential for significant improvements. However, there is also an element of risk with respect to device reliability. There are applications for which such a risk cannot be accepted. Thus, the challenge of implementing a new digital submarine cable system in 1988 has focused attention on reliability issues for new devices, such as optical sources and detectors. This challenge has led to a philosophy of reliability qualification which has been exceptionally successful and has implications for all new technology semiconductor devices. It is emphasized that the issue involved is reliability assurance as distinct from reliability. Very high stresses are employed to eliminate failure modes which are only weakly temperature activated. The technique involved in this approach is called 'purging'. Purging reduces the extent of redundancy design and establishes confidence in the deployment of new technology devices.