C.Bozturk,School of Technology,KSU 课件.ppt

C.Bozturk,School of Technology,KSU BURN-IN, RELIABILITY TESTING, AND MANUFACTURING OF SEMICONDUCTORS Prepared By Cagatay Bozturk Index What is BURN-IN? Reliability of Semiconductors What is ReliabilityLife Testing Semiconductor Manufacturing What is BURN-IN? Burn-In is the application of thermal and electrical stress for the purposes of inducing the failure of marginal (microelectronic) devices, those with inherent defects or defects resulting from manufacturing aberrations which cause time and stress dependant failures. Reliability of Semiconductors To evaluate the reliability of an electronic system, reliability information on the components used in that system is important. Failure rates are often used as an index for reliability. A failure rate indicates how often a failure occurs per unit time, and failure-rate values generally change overtime as shown below Early Failure Stage During this stage, failures occur at a high rate following the initial operation of semiconductor devices. They occur very soon and thus the failure rate declines rapidly over time. This Is because the potential failures that could not be removed through a selective process are included and surface in a short time if a stress such as temperature or voltage is applied after use of the device is started. In the case of semiconductors, these failures are usually due to defects that could not be removed during production, such an micro dust collecting on the wafer, or to material defects. Random Failure Stage When early failures are eliminated, the failure rate drops to an extremely low value. However, there is always the possibility of a potential failure accidentally occurring after a long time. Consequently the failure rate never decreases to zero. It is almost constant because failures occur sporadically Wear-out Failure Stage During this stage, failures occur with increasing frequency over time and are caused by age-related wear and fatigue. In the case of a semiconductor dev