In accordance with the JP-001 Foundry Process Qualification Guidelines, the X-FAB Quality Management System uses two levels of qualification tests:
Level 1 is a pure wafer process qualification intended to find reliability weaknesses by stressing and testing technology elements. It primarily addresses technology wearout mechanisms on specially designed test structures (carried out on wafer or packed level).
Level 2 demonstrates the reliability of the process by testing of a relevant functional technology qualification vehicle (TQV). It also covers the influence of complex interactions of process elements by accelerated lifetime simulation testing and accelerated environmental stress testing, respectively.
Non-volatile (NV) memories form a special category with extended requirements regarding qualification planning, data logging and data evaluation.
In order to check the stability of a production process regarding the reliability requirements that were validated during process qualification, technology conformance tests are performed on a regular base. These tests, which are applicable to qualified technologies transferred to production, cover the main reliability risks of a technology.
An integrated comprehensive process-monitoring program ensures that each delivery lot meets X-FAB's requirements for high outgoing quality and reliability.