E-test and sort functional test failure: SONOS wafer yield analysis

摘要

Yield analysis is one of the most important subjects in IC companies. During the initial stage of new process development, several factors can greatly impact the yield simultaneously. This paper describes a statistical way to diagnose sort yield loss issues of SONOS (Silicon-Oxide-Nitride-Oxide-Silicon) wafers by using E-test result. Besides that, the wafer sort failure can be recovered by double program/erase cycles. Furthermore, the test failure recovery mechanism is discussed in this paper as well.