HAST Applications: Acceleration Factors and Results for VLSI Components

    HAST (Highly Accelerated Stress Test) Articles:

    HAST Applications: Acceleration Factors and Results for VLSI Components

    Results and acceleration factors between several highly accelerated stress test (HAST) conditions and 85 °C / 85% relative humidity tests are given for NMOS EPROM’s (erasable programmable read-only memories) and CMOS RAMs (random-access memories). Two failure regimes exist in time: the earliest is below 25% cumulative failures and is due to passivation defects; beyond that, failures are due to passivation moisture saturation or wear out. Results are sensitive to device/process, passivation integrity, and test apparatus cleanliness. Failure predictions are dependent on which failure regime is used.

    This paper appears in: Reliability Physics Symposium, 1989. 27th Annual Proceedings, International